Adding upstream version 124.0.1.upstream/124.0.1

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

19 files changed, 5318 insertions, 0 deletions

diff --git a/python/mozbuild/mozpack/test/__init__.py b/python/mozbuild/mozpack/test/__init__.py
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/python/mozbuild/mozpack/test/__init__.py
diff --git a/python/mozbuild/mozpack/test/data/test_data b/python/mozbuild/mozpack/test/data/test_data
new file mode 100644
index 0000000000..fb7f0c4fc2
--- /dev/null
+++ b/python/mozbuild/mozpack/test/data/test_data
@@ -0,0 +1 @@
+test_data
\ No newline at end of file
diff --git a/python/mozbuild/mozpack/test/python.toml b/python/mozbuild/mozpack/test/python.toml
new file mode 100644
index 0000000000..c886e78cf1
--- /dev/null
+++ b/python/mozbuild/mozpack/test/python.toml
@@ -0,0 +1,32 @@
+[DEFAULT]
+subsuite = "mozbuild"
+
+["test_archive.py"]
+
+["test_chrome_flags.py"]
+
+["test_chrome_manifest.py"]
+
+["test_copier.py"]
+
+["test_errors.py"]
+
+["test_files.py"]
+
+["test_manifests.py"]
+
+["test_mozjar.py"]
+
+["test_packager.py"]
+
+["test_packager_formats.py"]
+
+["test_packager_l10n.py"]
+
+["test_packager_unpack.py"]
+
+["test_path.py"]
+
+["test_pkg.py"]
+
+["test_unify.py"]
diff --git a/python/mozbuild/mozpack/test/support/minify_js_verify.py b/python/mozbuild/mozpack/test/support/minify_js_verify.py
new file mode 100644
index 0000000000..88cc0ece0c
--- /dev/null
+++ b/python/mozbuild/mozpack/test/support/minify_js_verify.py
@@ -0,0 +1,15 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+import sys
+
+if len(sys.argv) != 4:
+    raise Exception("Usage: minify_js_verify <exitcode> <orig> <minified>")
+
+retcode = int(sys.argv[1])
+
+if retcode:
+    print("Error message", file=sys.stderr)
+
+sys.exit(retcode)
diff --git a/python/mozbuild/mozpack/test/test_archive.py b/python/mozbuild/mozpack/test/test_archive.py
new file mode 100644
index 0000000000..3417f279df
--- /dev/null
+++ b/python/mozbuild/mozpack/test/test_archive.py
@@ -0,0 +1,197 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+import hashlib
+import os
+import shutil
+import stat
+import tarfile
+import tempfile
+import unittest
+
+import pytest
+from mozunit import main
+
+from mozpack.archive import (
+    DEFAULT_MTIME,
+    create_tar_bz2_from_files,
+    create_tar_from_files,
+    create_tar_gz_from_files,
+)
+from mozpack.files import GeneratedFile
+
+MODE_STANDARD = stat.S_IRUSR | stat.S_IWUSR | stat.S_IRGRP | stat.S_IROTH
+
+
+def file_hash(path):
+    h = hashlib.sha1()
+    with open(path, "rb") as fh:
+        while True:
+            data = fh.read(8192)
+            if not data:
+                break
+            h.update(data)
+
+    return h.hexdigest()
+
+
+class TestArchive(unittest.TestCase):
+    def _create_files(self, root):
+        files = {}
+        for i in range(10):
+            p = os.path.join(root, "file%02d" % i)
+            with open(p, "wb") as fh:
+                fh.write(b"file%02d" % i)
+            # Need to set permissions or umask may influence testing.
+            os.chmod(p, MODE_STANDARD)
+            files["file%02d" % i] = p
+
+        for i in range(10):
+            files["file%02d" % (i + 10)] = GeneratedFile(b"file%02d" % (i + 10))
+
+        return files
+
+    def _verify_basic_tarfile(self, tf):
+        self.assertEqual(len(tf.getmembers()), 20)
+
+        names = ["file%02d" % i for i in range(20)]
+        self.assertEqual(tf.getnames(), names)
+
+        for ti in tf.getmembers():
+            self.assertEqual(ti.uid, 0)
+            self.assertEqual(ti.gid, 0)
+            self.assertEqual(ti.uname, "")
+            self.assertEqual(ti.gname, "")
+            self.assertEqual(ti.mode, MODE_STANDARD)
+            self.assertEqual(ti.mtime, DEFAULT_MTIME)
+
+    @pytest.mark.xfail(
+        reason="ValueError is not thrown despite being provided directory."
+    )
+    def test_dirs_refused(self):
+        d = tempfile.mkdtemp()
+        try:
+            tp = os.path.join(d, "test.tar")
+            with open(tp, "wb") as fh:
+                with self.assertRaisesRegexp(ValueError, "not a regular"):
+                    create_tar_from_files(fh, {"test": d})
+        finally:
+            shutil.rmtree(d)
+
+    @pytest.mark.xfail(reason="ValueError is not thrown despite uid/gid being set.")
+    def test_setuid_setgid_refused(self):
+        d = tempfile.mkdtemp()
+        try:
+            uid = os.path.join(d, "setuid")
+            gid = os.path.join(d, "setgid")
+            with open(uid, "a"):
+                pass
+            with open(gid, "a"):
+                pass
+
+            os.chmod(uid, MODE_STANDARD | stat.S_ISUID)
+            os.chmod(gid, MODE_STANDARD | stat.S_ISGID)
+
+            tp = os.path.join(d, "test.tar")
+            with open(tp, "wb") as fh:
+                with self.assertRaisesRegexp(ValueError, "cannot add file with setuid"):
+                    create_tar_from_files(fh, {"test": uid})
+                with self.assertRaisesRegexp(ValueError, "cannot add file with setuid"):
+                    create_tar_from_files(fh, {"test": gid})
+        finally:
+            shutil.rmtree(d)
+
+    def test_create_tar_basic(self):
+        d = tempfile.mkdtemp()
+        try:
+            files = self._create_files(d)
+
+            tp = os.path.join(d, "test.tar")
+            with open(tp, "wb") as fh:
+                create_tar_from_files(fh, files)
+
+            # Output should be deterministic.
+            self.assertEqual(file_hash(tp), "01cd314e277f060e98c7de6c8ea57f96b3a2065c")
+
+            with tarfile.open(tp, "r") as tf:
+                self._verify_basic_tarfile(tf)
+
+        finally:
+            shutil.rmtree(d)
+
+    @pytest.mark.xfail(reason="hash mismatch")
+    def test_executable_preserved(self):
+        d = tempfile.mkdtemp()
+        try:
+            p = os.path.join(d, "exec")
+            with open(p, "wb") as fh:
+                fh.write("#!/bin/bash\n")
+            os.chmod(p, MODE_STANDARD | stat.S_IXUSR)
+
+            tp = os.path.join(d, "test.tar")
+            with open(tp, "wb") as fh:
+                create_tar_from_files(fh, {"exec": p})
+
+            self.assertEqual(file_hash(tp), "357e1b81c0b6cfdfa5d2d118d420025c3c76ee93")
+
+            with tarfile.open(tp, "r") as tf:
+                m = tf.getmember("exec")
+                self.assertEqual(m.mode, MODE_STANDARD | stat.S_IXUSR)
+
+        finally:
+            shutil.rmtree(d)
+
+    def test_create_tar_gz_basic(self):
+        d = tempfile.mkdtemp()
+        try:
+            files = self._create_files(d)
+
+            gp = os.path.join(d, "test.tar.gz")
+            with open(gp, "wb") as fh:
+                create_tar_gz_from_files(fh, files)
+
+            self.assertEqual(file_hash(gp), "7c4da5adc5088cdf00911d5daf9a67b15de714b7")
+
+            with tarfile.open(gp, "r:gz") as tf:
+                self._verify_basic_tarfile(tf)
+
+        finally:
+            shutil.rmtree(d)
+
+    def test_tar_gz_name(self):
+        d = tempfile.mkdtemp()
+        try:
+            files = self._create_files(d)
+
+            gp = os.path.join(d, "test.tar.gz")
+            with open(gp, "wb") as fh:
+                create_tar_gz_from_files(fh, files, filename="foobar")
+
+            self.assertEqual(file_hash(gp), "721e00083c17d16df2edbddf40136298c06d0c49")
+
+            with tarfile.open(gp, "r:gz") as tf:
+                self._verify_basic_tarfile(tf)
+
+        finally:
+            shutil.rmtree(d)
+
+    def test_create_tar_bz2_basic(self):
+        d = tempfile.mkdtemp()
+        try:
+            files = self._create_files(d)
+
+            bp = os.path.join(d, "test.tar.bz2")
+            with open(bp, "wb") as fh:
+                create_tar_bz2_from_files(fh, files)
+
+            self.assertEqual(file_hash(bp), "eb5096d2fbb71df7b3d690001a6f2e82a5aad6a7")
+
+            with tarfile.open(bp, "r:bz2") as tf:
+                self._verify_basic_tarfile(tf)
+        finally:
+            shutil.rmtree(d)
+
+
+if __name__ == "__main__":
+    main()
diff --git a/python/mozbuild/mozpack/test/test_chrome_flags.py b/python/mozbuild/mozpack/test/test_chrome_flags.py
new file mode 100644
index 0000000000..4f1a968dc2
--- /dev/null
+++ b/python/mozbuild/mozpack/test/test_chrome_flags.py
@@ -0,0 +1,150 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+import unittest
+
+import mozunit
+
+from mozpack.chrome.flags import Flag, Flags, StringFlag, VersionFlag
+from mozpack.errors import ErrorMessage
+
+
+class TestFlag(unittest.TestCase):
+    def test_flag(self):
+        flag = Flag("flag")
+        self.assertEqual(str(flag), "")
+        self.assertTrue(flag.matches(False))
+        self.assertTrue(flag.matches("false"))
+        self.assertFalse(flag.matches("true"))
+        self.assertRaises(ErrorMessage, flag.add_definition, "flag=")
+        self.assertRaises(ErrorMessage, flag.add_definition, "flag=42")
+        self.assertRaises(ErrorMessage, flag.add_definition, "flag!=false")
+
+        flag.add_definition("flag=1")
+        self.assertEqual(str(flag), "flag=1")
+        self.assertTrue(flag.matches(True))
+        self.assertTrue(flag.matches("1"))
+        self.assertFalse(flag.matches("no"))
+
+        flag.add_definition("flag=true")
+        self.assertEqual(str(flag), "flag=true")
+        self.assertTrue(flag.matches(True))
+        self.assertTrue(flag.matches("true"))
+        self.assertFalse(flag.matches("0"))
+
+        flag.add_definition("flag=no")
+        self.assertEqual(str(flag), "flag=no")
+        self.assertTrue(flag.matches("false"))
+        self.assertFalse(flag.matches("1"))
+
+        flag.add_definition("flag")
+        self.assertEqual(str(flag), "flag")
+        self.assertFalse(flag.matches("false"))
+        self.assertTrue(flag.matches("true"))
+        self.assertFalse(flag.matches(False))
+
+    def test_string_flag(self):
+        flag = StringFlag("flag")
+        self.assertEqual(str(flag), "")
+        self.assertTrue(flag.matches("foo"))
+        self.assertRaises(ErrorMessage, flag.add_definition, "flag>=2")
+
+        flag.add_definition("flag=foo")
+        self.assertEqual(str(flag), "flag=foo")
+        self.assertTrue(flag.matches("foo"))
+        self.assertFalse(flag.matches("bar"))
+
+        flag.add_definition("flag=bar")
+        self.assertEqual(str(flag), "flag=foo flag=bar")
+        self.assertTrue(flag.matches("foo"))
+        self.assertTrue(flag.matches("bar"))
+        self.assertFalse(flag.matches("baz"))
+
+        flag = StringFlag("flag")
+        flag.add_definition("flag!=bar")
+        self.assertEqual(str(flag), "flag!=bar")
+        self.assertTrue(flag.matches("foo"))
+        self.assertFalse(flag.matches("bar"))
+
+    def test_version_flag(self):
+        flag = VersionFlag("flag")
+        self.assertEqual(str(flag), "")
+        self.assertTrue(flag.matches("1.0"))
+        self.assertRaises(ErrorMessage, flag.add_definition, "flag!=2")
+
+        flag.add_definition("flag=1.0")
+        self.assertEqual(str(flag), "flag=1.0")
+        self.assertTrue(flag.matches("1.0"))
+        self.assertFalse(flag.matches("2.0"))
+
+        flag.add_definition("flag=2.0")
+        self.assertEqual(str(flag), "flag=1.0 flag=2.0")
+        self.assertTrue(flag.matches("1.0"))
+        self.assertTrue(flag.matches("2.0"))
+        self.assertFalse(flag.matches("3.0"))
+
+        flag = VersionFlag("flag")
+        flag.add_definition("flag>=2.0")
+        self.assertEqual(str(flag), "flag>=2.0")
+        self.assertFalse(flag.matches("1.0"))
+        self.assertTrue(flag.matches("2.0"))
+        self.assertTrue(flag.matches("3.0"))
+
+        flag.add_definition("flag<1.10")
+        self.assertEqual(str(flag), "flag>=2.0 flag<1.10")
+        self.assertTrue(flag.matches("1.0"))
+        self.assertTrue(flag.matches("1.9"))
+        self.assertFalse(flag.matches("1.10"))
+        self.assertFalse(flag.matches("1.20"))
+        self.assertTrue(flag.matches("2.0"))
+        self.assertTrue(flag.matches("3.0"))
+        self.assertRaises(Exception, flag.add_definition, "flag<")
+        self.assertRaises(Exception, flag.add_definition, "flag>")
+        self.assertRaises(Exception, flag.add_definition, "flag>=")
+        self.assertRaises(Exception, flag.add_definition, "flag<=")
+        self.assertRaises(Exception, flag.add_definition, "flag!=1.0")
+
+
+class TestFlags(unittest.TestCase):
+    def setUp(self):
+        self.flags = Flags(
+            "contentaccessible=yes",
+            "appversion>=3.5",
+            "application=foo",
+            "application=bar",
+            "appversion<2.0",
+            "platform",
+            "abi!=Linux_x86-gcc3",
+        )
+
+    def test_flags_str(self):
+        self.assertEqual(
+            str(self.flags),
+            "contentaccessible=yes "
+            + "appversion>=3.5 appversion<2.0 application=foo "
+            + "application=bar platform abi!=Linux_x86-gcc3",
+        )
+
+    def test_flags_match_unset(self):
+        self.assertTrue(self.flags.match(os="WINNT"))
+
+    def test_flags_match(self):
+        self.assertTrue(self.flags.match(application="foo"))
+        self.assertFalse(self.flags.match(application="qux"))
+
+    def test_flags_match_different(self):
+        self.assertTrue(self.flags.match(abi="WINNT_x86-MSVC"))
+        self.assertFalse(self.flags.match(abi="Linux_x86-gcc3"))
+
+    def test_flags_match_version(self):
+        self.assertTrue(self.flags.match(appversion="1.0"))
+        self.assertTrue(self.flags.match(appversion="1.5"))
+        self.assertFalse(self.flags.match(appversion="2.0"))
+        self.assertFalse(self.flags.match(appversion="3.0"))
+        self.assertTrue(self.flags.match(appversion="3.5"))
+        self.assertTrue(self.flags.match(appversion="3.10"))
+
+
+if __name__ == "__main__":
+    mozunit.main()
diff --git a/python/mozbuild/mozpack/test/test_chrome_manifest.py b/python/mozbuild/mozpack/test/test_chrome_manifest.py
new file mode 100644
index 0000000000..c1d5826bbc
--- /dev/null
+++ b/python/mozbuild/mozpack/test/test_chrome_manifest.py
@@ -0,0 +1,176 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+import os
+import unittest
+
+import mozunit
+
+from mozpack.chrome.manifest import (
+    MANIFESTS_TYPES,
+    Manifest,
+    ManifestBinaryComponent,
+    ManifestCategory,
+    ManifestComponent,
+    ManifestContent,
+    ManifestContract,
+    ManifestInterfaces,
+    ManifestLocale,
+    ManifestOverlay,
+    ManifestOverride,
+    ManifestResource,
+    ManifestSkin,
+    ManifestStyle,
+    parse_manifest,
+    parse_manifest_line,
+)
+from mozpack.errors import AccumulatedErrors, errors
+from test_errors import TestErrors
+
+
+class TestManifest(unittest.TestCase):
+    def test_parse_manifest(self):
+        manifest = [
+            "content global content/global/",
+            "content global content/global/ application=foo application=bar"
+            + " platform",
+            "locale global en-US content/en-US/",
+            "locale global en-US content/en-US/ application=foo",
+            "skin global classic/1.0 content/skin/classic/",
+            "skin global classic/1.0 content/skin/classic/ application=foo"
+            + " os=WINNT",
+            "",
+            "manifest pdfjs/chrome.manifest",
+            "resource gre-resources toolkit/res/",
+            "override chrome://global/locale/netError.dtd"
+            + " chrome://browser/locale/netError.dtd",
+            "# Comment",
+            "component {b2bba4df-057d-41ea-b6b1-94a10a8ede68} foo.js",
+            "contract @mozilla.org/foo;1" + " {b2bba4df-057d-41ea-b6b1-94a10a8ede68}",
+            "interfaces foo.xpt",
+            "binary-component bar.so",
+            "category command-line-handler m-browser"
+            + " @mozilla.org/browser/clh;1"
+            + " application={ec8030f7-c20a-464f-9b0e-13a3a9e97384}",
+            "style chrome://global/content/viewSource.xul" + " chrome://browser/skin/",
+            "overlay chrome://global/content/viewSource.xul"
+            + " chrome://browser/content/viewSourceOverlay.xul",
+        ]
+        other_manifest = ["content global content/global/"]
+        expected_result = [
+            ManifestContent("", "global", "content/global/"),
+            ManifestContent(
+                "",
+                "global",
+                "content/global/",
+                "application=foo",
+                "application=bar",
+                "platform",
+            ),
+            ManifestLocale("", "global", "en-US", "content/en-US/"),
+            ManifestLocale("", "global", "en-US", "content/en-US/", "application=foo"),
+            ManifestSkin("", "global", "classic/1.0", "content/skin/classic/"),
+            ManifestSkin(
+                "",
+                "global",
+                "classic/1.0",
+                "content/skin/classic/",
+                "application=foo",
+                "os=WINNT",
+            ),
+            Manifest("", "pdfjs/chrome.manifest"),
+            ManifestResource("", "gre-resources", "toolkit/res/"),
+            ManifestOverride(
+                "",
+                "chrome://global/locale/netError.dtd",
+                "chrome://browser/locale/netError.dtd",
+            ),
+            ManifestComponent("", "{b2bba4df-057d-41ea-b6b1-94a10a8ede68}", "foo.js"),
+            ManifestContract(
+                "", "@mozilla.org/foo;1", "{b2bba4df-057d-41ea-b6b1-94a10a8ede68}"
+            ),
+            ManifestInterfaces("", "foo.xpt"),
+            ManifestBinaryComponent("", "bar.so"),
+            ManifestCategory(
+                "",
+                "command-line-handler",
+                "m-browser",
+                "@mozilla.org/browser/clh;1",
+                "application=" + "{ec8030f7-c20a-464f-9b0e-13a3a9e97384}",
+            ),
+            ManifestStyle(
+                "", "chrome://global/content/viewSource.xul", "chrome://browser/skin/"
+            ),
+            ManifestOverlay(
+                "",
+                "chrome://global/content/viewSource.xul",
+                "chrome://browser/content/viewSourceOverlay.xul",
+            ),
+        ]
+        with mozunit.MockedOpen(
+            {
+                "manifest": "\n".join(manifest),
+                "other/manifest": "\n".join(other_manifest),
+            }
+        ):
+            # Ensure we have tests for all types of manifests.
+            self.assertEqual(
+                set(type(e) for e in expected_result), set(MANIFESTS_TYPES.values())
+            )
+            self.assertEqual(
+                list(parse_manifest(os.curdir, "manifest")), expected_result
+            )
+            self.assertEqual(
+                list(parse_manifest(os.curdir, "other/manifest")),
+                [ManifestContent("other", "global", "content/global/")],
+            )
+
+    def test_manifest_rebase(self):
+        m = parse_manifest_line("chrome", "content global content/global/")
+        m = m.rebase("")
+        self.assertEqual(str(m), "content global chrome/content/global/")
+        m = m.rebase("chrome")
+        self.assertEqual(str(m), "content global content/global/")
+
+        m = parse_manifest_line("chrome/foo", "content global content/global/")
+        m = m.rebase("chrome")
+        self.assertEqual(str(m), "content global foo/content/global/")
+        m = m.rebase("chrome/foo")
+        self.assertEqual(str(m), "content global content/global/")
+
+        m = parse_manifest_line("modules/foo", "resource foo ./")
+        m = m.rebase("modules")
+        self.assertEqual(str(m), "resource foo foo/")
+        m = m.rebase("modules/foo")
+        self.assertEqual(str(m), "resource foo ./")
+
+        m = parse_manifest_line("chrome", "content browser browser/content/")
+        m = m.rebase("chrome/browser").move("jar:browser.jar!").rebase("")
+        self.assertEqual(str(m), "content browser jar:browser.jar!/content/")
+
+
+class TestManifestErrors(TestErrors, unittest.TestCase):
+    def test_parse_manifest_errors(self):
+        manifest = [
+            "skin global classic/1.0 content/skin/classic/ platform",
+            "",
+            "binary-component bar.so",
+            "unsupported foo",
+        ]
+        with mozunit.MockedOpen({"manifest": "\n".join(manifest)}):
+            with self.assertRaises(AccumulatedErrors):
+                with errors.accumulate():
+                    list(parse_manifest(os.curdir, "manifest"))
+            out = self.get_output()
+            # Expecting 2 errors
+            self.assertEqual(len(out), 2)
+            path = os.path.abspath("manifest")
+            # First on line 1
+            self.assertTrue(out[0].startswith("error: %s:1: " % path))
+            # Second on line 4
+            self.assertTrue(out[1].startswith("error: %s:4: " % path))
+
+
+if __name__ == "__main__":
+    mozunit.main()
diff --git a/python/mozbuild/mozpack/test/test_copier.py b/python/mozbuild/mozpack/test/test_copier.py
new file mode 100644
index 0000000000..60ebd2c1e9
--- /dev/null
+++ b/python/mozbuild/mozpack/test/test_copier.py
@@ -0,0 +1,548 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+import os
+import stat
+import unittest
+
+import mozunit
+import six
+
+import mozpack.path as mozpath
+from mozpack.copier import FileCopier, FileRegistry, FileRegistrySubtree, Jarrer
+from mozpack.errors import ErrorMessage
+from mozpack.files import ExistingFile, GeneratedFile
+from mozpack.mozjar import JarReader
+from mozpack.test.test_files import MatchTestTemplate, MockDest, TestWithTmpDir
+
+
+class BaseTestFileRegistry(MatchTestTemplate):
+    def add(self, path):
+        self.registry.add(path, GeneratedFile(path))
+
+    def do_check(self, pattern, result):
+        self.checked = True
+        if result:
+            self.assertTrue(self.registry.contains(pattern))
+        else:
+            self.assertFalse(self.registry.contains(pattern))
+        self.assertEqual(self.registry.match(pattern), result)
+
+    def do_test_file_registry(self, registry):
+        self.registry = registry
+        self.registry.add("foo", GeneratedFile(b"foo"))
+        bar = GeneratedFile(b"bar")
+        self.registry.add("bar", bar)
+        self.assertEqual(self.registry.paths(), ["foo", "bar"])
+        self.assertEqual(self.registry["bar"], bar)
+
+        self.assertRaises(
+            ErrorMessage, self.registry.add, "foo", GeneratedFile(b"foo2")
+        )
+
+        self.assertRaises(ErrorMessage, self.registry.remove, "qux")
+
+        self.assertRaises(
+            ErrorMessage, self.registry.add, "foo/bar", GeneratedFile(b"foobar")
+        )
+        self.assertRaises(
+            ErrorMessage, self.registry.add, "foo/bar/baz", GeneratedFile(b"foobar")
+        )
+
+        self.assertEqual(self.registry.paths(), ["foo", "bar"])
+
+        self.registry.remove("foo")
+        self.assertEqual(self.registry.paths(), ["bar"])
+        self.registry.remove("bar")
+        self.assertEqual(self.registry.paths(), [])
+
+        self.prepare_match_test()
+        self.do_match_test()
+        self.assertTrue(self.checked)
+        self.assertEqual(
+            self.registry.paths(),
+            [
+                "bar",
+                "foo/bar",
+                "foo/baz",
+                "foo/qux/1",
+                "foo/qux/bar",
+                "foo/qux/2/test",
+                "foo/qux/2/test2",
+            ],
+        )
+
+        self.registry.remove("foo/qux")
+        self.assertEqual(self.registry.paths(), ["bar", "foo/bar", "foo/baz"])
+
+        self.registry.add("foo/qux", GeneratedFile(b"fooqux"))
+        self.assertEqual(
+            self.registry.paths(), ["bar", "foo/bar", "foo/baz", "foo/qux"]
+        )
+        self.registry.remove("foo/b*")
+        self.assertEqual(self.registry.paths(), ["bar", "foo/qux"])
+
+        self.assertEqual([f for f, c in self.registry], ["bar", "foo/qux"])
+        self.assertEqual(len(self.registry), 2)
+
+        self.add("foo/.foo")
+        self.assertTrue(self.registry.contains("foo/.foo"))
+
+    def do_test_registry_paths(self, registry):
+        self.registry = registry
+
+        # Can't add a file if it requires a directory in place of a
+        # file we also require.
+        self.registry.add("foo", GeneratedFile(b"foo"))
+        self.assertRaises(
+            ErrorMessage, self.registry.add, "foo/bar", GeneratedFile(b"foobar")
+        )
+
+        # Can't add a file if we already have a directory there.
+        self.registry.add("bar/baz", GeneratedFile(b"barbaz"))
+        self.assertRaises(ErrorMessage, self.registry.add, "bar", GeneratedFile(b"bar"))
+
+        # Bump the count of things that require bar/ to 2.
+        self.registry.add("bar/zot", GeneratedFile(b"barzot"))
+        self.assertRaises(ErrorMessage, self.registry.add, "bar", GeneratedFile(b"bar"))
+
+        # Drop the count of things that require bar/ to 1.
+        self.registry.remove("bar/baz")
+        self.assertRaises(ErrorMessage, self.registry.add, "bar", GeneratedFile(b"bar"))
+
+        # Drop the count of things that require bar/ to 0.
+        self.registry.remove("bar/zot")
+        self.registry.add("bar/zot", GeneratedFile(b"barzot"))
+
+
+class TestFileRegistry(BaseTestFileRegistry, unittest.TestCase):
+    def test_partial_paths(self):
+        cases = {
+            "foo/bar/baz/zot": ["foo/bar/baz", "foo/bar", "foo"],
+            "foo/bar": ["foo"],
+            "bar": [],
+        }
+        reg = FileRegistry()
+        for path, parts in six.iteritems(cases):
+            self.assertEqual(reg._partial_paths(path), parts)
+
+    def test_file_registry(self):
+        self.do_test_file_registry(FileRegistry())
+
+    def test_registry_paths(self):
+        self.do_test_registry_paths(FileRegistry())
+
+    def test_required_directories(self):
+        self.registry = FileRegistry()
+
+        self.registry.add("foo", GeneratedFile(b"foo"))
+        self.assertEqual(self.registry.required_directories(), set())
+
+        self.registry.add("bar/baz", GeneratedFile(b"barbaz"))
+        self.assertEqual(self.registry.required_directories(), {"bar"})
+
+        self.registry.add("bar/zot", GeneratedFile(b"barzot"))
+        self.assertEqual(self.registry.required_directories(), {"bar"})
+
+        self.registry.add("bar/zap/zot", GeneratedFile(b"barzapzot"))
+        self.assertEqual(self.registry.required_directories(), {"bar", "bar/zap"})
+
+        self.registry.remove("bar/zap/zot")
+        self.assertEqual(self.registry.required_directories(), {"bar"})
+
+        self.registry.remove("bar/baz")
+        self.assertEqual(self.registry.required_directories(), {"bar"})
+
+        self.registry.remove("bar/zot")
+        self.assertEqual(self.registry.required_directories(), set())
+
+        self.registry.add("x/y/z", GeneratedFile(b"xyz"))
+        self.assertEqual(self.registry.required_directories(), {"x", "x/y"})
+
+
+class TestFileRegistrySubtree(BaseTestFileRegistry, unittest.TestCase):
+    def test_file_registry_subtree_base(self):
+        registry = FileRegistry()
+        self.assertEqual(registry, FileRegistrySubtree("", registry))
+        self.assertNotEqual(registry, FileRegistrySubtree("base", registry))
+
+    def create_registry(self):
+        registry = FileRegistry()
+        registry.add("foo/bar", GeneratedFile(b"foo/bar"))
+        registry.add("baz/qux", GeneratedFile(b"baz/qux"))
+        return FileRegistrySubtree("base/root", registry)
+
+    def test_file_registry_subtree(self):
+        self.do_test_file_registry(self.create_registry())
+
+    def test_registry_paths_subtree(self):
+        FileRegistry()
+        self.do_test_registry_paths(self.create_registry())
+
+
+class TestFileCopier(TestWithTmpDir):
+    def all_dirs(self, base):
+        all_dirs = set()
+        for root, dirs, files in os.walk(base):
+            if not dirs:
+                all_dirs.add(mozpath.relpath(root, base))
+        return all_dirs
+
+    def all_files(self, base):
+        all_files = set()
+        for root, dirs, files in os.walk(base):
+            for f in files:
+                all_files.add(mozpath.join(mozpath.relpath(root, base), f))
+        return all_files
+
+    def test_file_copier(self):
+        copier = FileCopier()
+        copier.add("foo/bar", GeneratedFile(b"foobar"))
+        copier.add("foo/qux", GeneratedFile(b"fooqux"))
+        copier.add("foo/deep/nested/directory/file", GeneratedFile(b"fooz"))
+        copier.add("bar", GeneratedFile(b"bar"))
+        copier.add("qux/foo", GeneratedFile(b"quxfoo"))
+        copier.add("qux/bar", GeneratedFile(b""))
+
+        result = copier.copy(self.tmpdir)
+        self.assertEqual(self.all_files(self.tmpdir), set(copier.paths()))
+        self.assertEqual(
+            self.all_dirs(self.tmpdir), set(["foo/deep/nested/directory", "qux"])
+        )
+
+        self.assertEqual(
+            result.updated_files,
+            set(self.tmppath(p) for p in self.all_files(self.tmpdir)),
+        )
+        self.assertEqual(result.existing_files, set())
+        self.assertEqual(result.removed_files, set())
+        self.assertEqual(result.removed_directories, set())
+
+        copier.remove("foo")
+        copier.add("test", GeneratedFile(b"test"))
+        result = copier.copy(self.tmpdir)
+        self.assertEqual(self.all_files(self.tmpdir), set(copier.paths()))
+        self.assertEqual(self.all_dirs(self.tmpdir), set(["qux"]))
+        self.assertEqual(
+            result.removed_files,
+            set(
+                self.tmppath(p)
+                for p in ("foo/bar", "foo/qux", "foo/deep/nested/directory/file")
+            ),
+        )
+
+    def test_symlink_directory_replaced(self):
+        """Directory symlinks in destination are replaced if they need to be
+        real directories."""
+        if not self.symlink_supported:
+            return
+
+        dest = self.tmppath("dest")
+
+        copier = FileCopier()
+        copier.add("foo/bar/baz", GeneratedFile(b"foobarbaz"))
+
+        os.makedirs(self.tmppath("dest/foo"))
+        dummy = self.tmppath("dummy")
+        os.mkdir(dummy)
+        link = self.tmppath("dest/foo/bar")
+        os.symlink(dummy, link)
+
+        result = copier.copy(dest)
+
+        st = os.lstat(link)
+        self.assertFalse(stat.S_ISLNK(st.st_mode))
+        self.assertTrue(stat.S_ISDIR(st.st_mode))
+
+        self.assertEqual(self.all_files(dest), set(copier.paths()))
+
+        self.assertEqual(result.removed_directories, set())
+        self.assertEqual(len(result.updated_files), 1)
+
+    def test_remove_unaccounted_directory_symlinks(self):
+        """Directory symlinks in destination that are not in the way are
+        deleted according to remove_unaccounted and
+        remove_all_directory_symlinks.
+        """
+        if not self.symlink_supported:
+            return
+
+        dest = self.tmppath("dest")
+
+        copier = FileCopier()
+        copier.add("foo/bar/baz", GeneratedFile(b"foobarbaz"))
+
+        os.makedirs(self.tmppath("dest/foo"))
+        dummy = self.tmppath("dummy")
+        os.mkdir(dummy)
+
+        os.mkdir(self.tmppath("dest/zot"))
+        link = self.tmppath("dest/zot/zap")
+        os.symlink(dummy, link)
+
+        # If not remove_unaccounted but remove_empty_directories, then
+        # the symlinked directory remains (as does its containing
+        # directory).
+        result = copier.copy(
+            dest,
+            remove_unaccounted=False,
+            remove_empty_directories=True,
+            remove_all_directory_symlinks=False,
+        )
+
+        st = os.lstat(link)
+        self.assertTrue(stat.S_ISLNK(st.st_mode))
+        self.assertFalse(stat.S_ISDIR(st.st_mode))
+
+        self.assertEqual(self.all_files(dest), set(copier.paths()))
+        self.assertEqual(self.all_dirs(dest), set(["foo/bar"]))
+
+        self.assertEqual(result.removed_directories, set())
+        self.assertEqual(len(result.updated_files), 1)
+
+        # If remove_unaccounted but not remove_empty_directories, then
+        # only the symlinked directory is removed.
+        result = copier.copy(
+            dest,
+            remove_unaccounted=True,
+            remove_empty_directories=False,
+            remove_all_directory_symlinks=False,
+        )
+
+        st = os.lstat(self.tmppath("dest/zot"))
+        self.assertFalse(stat.S_ISLNK(st.st_mode))
+        self.assertTrue(stat.S_ISDIR(st.st_mode))
+
+        self.assertEqual(result.removed_files, set([link]))
+        self.assertEqual(result.removed_directories, set())
+
+        self.assertEqual(self.all_files(dest), set(copier.paths()))
+        self.assertEqual(self.all_dirs(dest), set(["foo/bar", "zot"]))
+
+        # If remove_unaccounted and remove_empty_directories, then
+        # both the symlink and its containing directory are removed.
+        link = self.tmppath("dest/zot/zap")
+        os.symlink(dummy, link)
+
+        result = copier.copy(
+            dest,
+            remove_unaccounted=True,
+            remove_empty_directories=True,
+            remove_all_directory_symlinks=False,
+        )
+
+        self.assertEqual(result.removed_files, set([link]))
+        self.assertEqual(result.removed_directories, set([self.tmppath("dest/zot")]))
+
+        self.assertEqual(self.all_files(dest), set(copier.paths()))
+        self.assertEqual(self.all_dirs(dest), set(["foo/bar"]))
+
+    def test_permissions(self):
+        """Ensure files without write permission can be deleted."""
+        with open(self.tmppath("dummy"), "a"):
+            pass
+
+        p = self.tmppath("no_perms")
+        with open(p, "a"):
+            pass
+
+        # Make file and directory unwritable. Reminder: making a directory
+        # unwritable prevents modifications (including deletes) from the list
+        # of files in that directory.
+        os.chmod(p, 0o400)
+        os.chmod(self.tmpdir, 0o400)
+
+        copier = FileCopier()
+        copier.add("dummy", GeneratedFile(b"content"))
+        result = copier.copy(self.tmpdir)
+        self.assertEqual(result.removed_files_count, 1)
+        self.assertFalse(os.path.exists(p))
+
+    def test_no_remove(self):
+        copier = FileCopier()
+        copier.add("foo", GeneratedFile(b"foo"))
+
+        with open(self.tmppath("bar"), "a"):
+            pass
+
+        os.mkdir(self.tmppath("emptydir"))
+        d = self.tmppath("populateddir")
+        os.mkdir(d)
+
+        with open(self.tmppath("populateddir/foo"), "a"):
+            pass
+
+        result = copier.copy(self.tmpdir, remove_unaccounted=False)
+
+        self.assertEqual(
+            self.all_files(self.tmpdir), set(["foo", "bar", "populateddir/foo"])
+        )
+        self.assertEqual(self.all_dirs(self.tmpdir), set(["populateddir"]))
+        self.assertEqual(result.removed_files, set())
+        self.assertEqual(result.removed_directories, set([self.tmppath("emptydir")]))
+
+    def test_no_remove_empty_directories(self):
+        copier = FileCopier()
+        copier.add("foo", GeneratedFile(b"foo"))
+
+        with open(self.tmppath("bar"), "a"):
+            pass
+
+        os.mkdir(self.tmppath("emptydir"))
+        d = self.tmppath("populateddir")
+        os.mkdir(d)
+
+        with open(self.tmppath("populateddir/foo"), "a"):
+            pass
+
+        result = copier.copy(
+            self.tmpdir, remove_unaccounted=False, remove_empty_directories=False
+        )
+
+        self.assertEqual(
+            self.all_files(self.tmpdir), set(["foo", "bar", "populateddir/foo"])
+        )
+        self.assertEqual(self.all_dirs(self.tmpdir), set(["emptydir", "populateddir"]))
+        self.assertEqual(result.removed_files, set())
+        self.assertEqual(result.removed_directories, set())
+
+    def test_optional_exists_creates_unneeded_directory(self):
+        """Demonstrate that a directory not strictly required, but specified
+        as the path to an optional file, will be unnecessarily created.
+
+        This behaviour is wrong; fixing it is tracked by Bug 972432;
+        and this test exists to guard against unexpected changes in
+        behaviour.
+        """
+
+        dest = self.tmppath("dest")
+
+        copier = FileCopier()
+        copier.add("foo/bar", ExistingFile(required=False))
+
+        result = copier.copy(dest)
+
+        st = os.lstat(self.tmppath("dest/foo"))
+        self.assertFalse(stat.S_ISLNK(st.st_mode))
+        self.assertTrue(stat.S_ISDIR(st.st_mode))
+
+        # What's worse, we have no record that dest was created.
+        self.assertEqual(len(result.updated_files), 0)
+
+        # But we do have an erroneous record of an optional file
+        # existing when it does not.
+        self.assertIn(self.tmppath("dest/foo/bar"), result.existing_files)
+
+    def test_remove_unaccounted_file_registry(self):
+        """Test FileCopier.copy(remove_unaccounted=FileRegistry())"""
+
+        dest = self.tmppath("dest")
+
+        copier = FileCopier()
+        copier.add("foo/bar/baz", GeneratedFile(b"foobarbaz"))
+        copier.add("foo/bar/qux", GeneratedFile(b"foobarqux"))
+        copier.add("foo/hoge/fuga", GeneratedFile(b"foohogefuga"))
+        copier.add("foo/toto/tata", GeneratedFile(b"footototata"))
+
+        os.makedirs(os.path.join(dest, "bar"))
+        with open(os.path.join(dest, "bar", "bar"), "w") as fh:
+            fh.write("barbar")
+        os.makedirs(os.path.join(dest, "foo", "toto"))
+        with open(os.path.join(dest, "foo", "toto", "toto"), "w") as fh:
+            fh.write("foototototo")
+
+        result = copier.copy(dest, remove_unaccounted=False)
+
+        self.assertEqual(
+            self.all_files(dest), set(copier.paths()) | {"foo/toto/toto", "bar/bar"}
+        )
+        self.assertEqual(
+            self.all_dirs(dest), {"foo/bar", "foo/hoge", "foo/toto", "bar"}
+        )
+
+        copier2 = FileCopier()
+        copier2.add("foo/hoge/fuga", GeneratedFile(b"foohogefuga"))
+
+        # We expect only files copied from the first copier to be removed,
+        # not the extra file that was there beforehand.
+        result = copier2.copy(dest, remove_unaccounted=copier)
+
+        self.assertEqual(
+            self.all_files(dest), set(copier2.paths()) | {"foo/toto/toto", "bar/bar"}
+        )
+        self.assertEqual(self.all_dirs(dest), {"foo/hoge", "foo/toto", "bar"})
+        self.assertEqual(result.updated_files, {self.tmppath("dest/foo/hoge/fuga")})
+        self.assertEqual(result.existing_files, set())
+        self.assertEqual(
+            result.removed_files,
+            {
+                self.tmppath(p)
+                for p in ("dest/foo/bar/baz", "dest/foo/bar/qux", "dest/foo/toto/tata")
+            },
+        )
+        self.assertEqual(result.removed_directories, {self.tmppath("dest/foo/bar")})
+
+
+class TestJarrer(unittest.TestCase):
+    def check_jar(self, dest, copier):
+        jar = JarReader(fileobj=dest)
+        self.assertEqual([f.filename for f in jar], copier.paths())
+        for f in jar:
+            self.assertEqual(f.uncompressed_data.read(), copier[f.filename].content)
+
+    def test_jarrer(self):
+        copier = Jarrer()
+        copier.add("foo/bar", GeneratedFile(b"foobar"))
+        copier.add("foo/qux", GeneratedFile(b"fooqux"))
+        copier.add("foo/deep/nested/directory/file", GeneratedFile(b"fooz"))
+        copier.add("bar", GeneratedFile(b"bar"))
+        copier.add("qux/foo", GeneratedFile(b"quxfoo"))
+        copier.add("qux/bar", GeneratedFile(b""))
+
+        dest = MockDest()
+        copier.copy(dest)
+        self.check_jar(dest, copier)
+
+        copier.remove("foo")
+        copier.add("test", GeneratedFile(b"test"))
+        copier.copy(dest)
+        self.check_jar(dest, copier)
+
+        copier.remove("test")
+        copier.add("test", GeneratedFile(b"replaced-content"))
+        copier.copy(dest)
+        self.check_jar(dest, copier)
+
+        copier.copy(dest)
+        self.check_jar(dest, copier)
+
+        preloaded = ["qux/bar", "bar"]
+        copier.preload(preloaded)
+        copier.copy(dest)
+
+        dest.seek(0)
+        jar = JarReader(fileobj=dest)
+        self.assertEqual(
+            [f.filename for f in jar],
+            preloaded + [p for p in copier.paths() if p not in preloaded],
+        )
+        self.assertEqual(jar.last_preloaded, preloaded[-1])
+
+    def test_jarrer_compress(self):
+        copier = Jarrer()
+        copier.add("foo/bar", GeneratedFile(b"ffffff"))
+        copier.add("foo/qux", GeneratedFile(b"ffffff"), compress=False)
+
+        dest = MockDest()
+        copier.copy(dest)
+        self.check_jar(dest, copier)
+
+        dest.seek(0)
+        jar = JarReader(fileobj=dest)
+        self.assertTrue(jar["foo/bar"].compressed)
+        self.assertFalse(jar["foo/qux"].compressed)
+
+
+if __name__ == "__main__":
+    mozunit.main()
diff --git a/python/mozbuild/mozpack/test/test_errors.py b/python/mozbuild/mozpack/test/test_errors.py
new file mode 100644
index 0000000000..411b1b54c3
--- /dev/null
+++ b/python/mozbuild/mozpack/test/test_errors.py
@@ -0,0 +1,95 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+import sys
+import unittest
+
+import mozunit
+import six
+
+from mozpack.errors import AccumulatedErrors, ErrorMessage, errors
+
+
+class TestErrors(object):
+    def setUp(self):
+        errors.out = six.moves.cStringIO()
+        errors.ignore_errors(False)
+
+    def tearDown(self):
+        errors.out = sys.stderr
+
+    def get_output(self):
+        return [l.strip() for l in errors.out.getvalue().splitlines()]
+
+
+class TestErrorsImpl(TestErrors, unittest.TestCase):
+    def test_plain_error(self):
+        errors.warn("foo")
+        self.assertRaises(ErrorMessage, errors.error, "foo")
+        self.assertRaises(ErrorMessage, errors.fatal, "foo")
+        self.assertEqual(self.get_output(), ["warning: foo"])
+
+    def test_ignore_errors(self):
+        errors.ignore_errors()
+        errors.warn("foo")
+        errors.error("bar")
+        self.assertRaises(ErrorMessage, errors.fatal, "foo")
+        self.assertEqual(self.get_output(), ["warning: foo", "warning: bar"])
+
+    def test_no_error(self):
+        with errors.accumulate():
+            errors.warn("1")
+
+    def test_simple_error(self):
+        with self.assertRaises(AccumulatedErrors):
+            with errors.accumulate():
+                errors.error("1")
+        self.assertEqual(self.get_output(), ["error: 1"])
+
+    def test_error_loop(self):
+        with self.assertRaises(AccumulatedErrors):
+            with errors.accumulate():
+                for i in range(3):
+                    errors.error("%d" % i)
+        self.assertEqual(self.get_output(), ["error: 0", "error: 1", "error: 2"])
+
+    def test_multiple_errors(self):
+        with self.assertRaises(AccumulatedErrors):
+            with errors.accumulate():
+                errors.error("foo")
+                for i in range(3):
+                    if i == 2:
+                        errors.warn("%d" % i)
+                    else:
+                        errors.error("%d" % i)
+                errors.error("bar")
+        self.assertEqual(
+            self.get_output(),
+            ["error: foo", "error: 0", "error: 1", "warning: 2", "error: bar"],
+        )
+
+    def test_errors_context(self):
+        with self.assertRaises(AccumulatedErrors):
+            with errors.accumulate():
+                self.assertEqual(errors.get_context(), None)
+                with errors.context("foo", 1):
+                    self.assertEqual(errors.get_context(), ("foo", 1))
+                    errors.error("a")
+                    with errors.context("bar", 2):
+                        self.assertEqual(errors.get_context(), ("bar", 2))
+                        errors.error("b")
+                    self.assertEqual(errors.get_context(), ("foo", 1))
+                    errors.error("c")
+        self.assertEqual(
+            self.get_output(),
+            [
+                "error: foo:1: a",
+                "error: bar:2: b",
+                "error: foo:1: c",
+            ],
+        )
+
+
+if __name__ == "__main__":
+    mozunit.main()
diff --git a/python/mozbuild/mozpack/test/test_files.py b/python/mozbuild/mozpack/test/test_files.py
new file mode 100644
index 0000000000..1c86f2e0cc
--- /dev/null
+++ b/python/mozbuild/mozpack/test/test_files.py
@@ -0,0 +1,1362 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+from mozbuild.util import ensure_bytes, ensureParentDir
+from mozpack.errors import ErrorMessage, errors
+from mozpack.files import (
+    AbsoluteSymlinkFile,
+    ComposedFinder,
+    DeflatedFile,
+    Dest,
+    ExistingFile,
+    ExtractedTarFile,
+    File,
+    FileFinder,
+    GeneratedFile,
+    HardlinkFile,
+    JarFinder,
+    ManifestFile,
+    MercurialFile,
+    MercurialRevisionFinder,
+    MinifiedCommentStripped,
+    MinifiedJavaScript,
+    PreprocessedFile,
+    TarFinder,
+)
+
+# We don't have hglib installed everywhere.
+try:
+    import hglib
+except ImportError:
+    hglib = None
+
+import os
+import platform
+import random
+import sys
+import tarfile
+import unittest
+from io import BytesIO
+from tempfile import mkdtemp
+
+import mozfile
+import mozunit
+import six
+
+import mozpack.path as mozpath
+from mozpack.chrome.manifest import (
+    ManifestContent,
+    ManifestLocale,
+    ManifestOverride,
+    ManifestResource,
+)
+from mozpack.mozjar import JarReader, JarWriter
+
+
+class TestWithTmpDir(unittest.TestCase):
+    def setUp(self):
+        self.tmpdir = mkdtemp()
+
+        self.symlink_supported = False
+        self.hardlink_supported = False
+
+        # See comment in mozpack.files.AbsoluteSymlinkFile
+        if hasattr(os, "symlink") and platform.system() != "Windows":
+            dummy_path = self.tmppath("dummy_file")
+            with open(dummy_path, "a"):
+                pass
+
+            try:
+                os.symlink(dummy_path, self.tmppath("dummy_symlink"))
+                os.remove(self.tmppath("dummy_symlink"))
+            except EnvironmentError:
+                pass
+            finally:
+                os.remove(dummy_path)
+
+            self.symlink_supported = True
+
+        if hasattr(os, "link"):
+            dummy_path = self.tmppath("dummy_file")
+            with open(dummy_path, "a"):
+                pass
+
+            try:
+                os.link(dummy_path, self.tmppath("dummy_hardlink"))
+                os.remove(self.tmppath("dummy_hardlink"))
+            except EnvironmentError:
+                pass
+            finally:
+                os.remove(dummy_path)
+
+            self.hardlink_supported = True
+
+    def tearDown(self):
+        mozfile.rmtree(self.tmpdir)
+
+    def tmppath(self, relpath):
+        return os.path.normpath(os.path.join(self.tmpdir, relpath))
+
+
+class MockDest(BytesIO, Dest):
+    def __init__(self):
+        BytesIO.__init__(self)
+        self.mode = None
+
+    def read(self, length=-1):
+        if self.mode != "r":
+            self.seek(0)
+            self.mode = "r"
+        return BytesIO.read(self, length)
+
+    def write(self, data):
+        if self.mode != "w":
+            self.seek(0)
+            self.truncate(0)
+            self.mode = "w"
+        return BytesIO.write(self, data)
+
+    def exists(self):
+        return True
+
+    def close(self):
+        if self.mode:
+            self.mode = None
+
+
+class DestNoWrite(Dest):
+    def write(self, data):
+        raise RuntimeError
+
+
+class TestDest(TestWithTmpDir):
+    def test_dest(self):
+        dest = Dest(self.tmppath("dest"))
+        self.assertFalse(dest.exists())
+        dest.write(b"foo")
+        self.assertTrue(dest.exists())
+        dest.write(b"foo")
+        self.assertEqual(dest.read(4), b"foof")
+        self.assertEqual(dest.read(), b"oo")
+        self.assertEqual(dest.read(), b"")
+        dest.write(b"bar")
+        self.assertEqual(dest.read(4), b"bar")
+        dest.close()
+        self.assertEqual(dest.read(), b"bar")
+        dest.write(b"foo")
+        dest.close()
+        dest.write(b"qux")
+        self.assertEqual(dest.read(), b"qux")
+
+
+rand = bytes(
+    random.choice(b"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ")
+    for i in six.moves.xrange(131597)
+)
+samples = [
+    b"",
+    b"test",
+    b"fooo",
+    b"same",
+    b"same",
+    b"Different and longer",
+    rand,
+    rand,
+    rand[:-1] + b"_",
+    b"test",
+]
+
+
+class TestFile(TestWithTmpDir):
+    def test_file(self):
+        """
+        Check that File.copy yields the proper content in the destination file
+        in all situations that trigger different code paths:
+        - different content
+        - different content of the same size
+        - same content
+        - long content
+        """
+        src = self.tmppath("src")
+        dest = self.tmppath("dest")
+
+        for content in samples:
+            with open(src, "wb") as tmp:
+                tmp.write(content)
+            # Ensure the destination file, when it exists, is older than the
+            # source
+            if os.path.exists(dest):
+                time = os.path.getmtime(src) - 1
+                os.utime(dest, (time, time))
+            f = File(src)
+            f.copy(dest)
+            self.assertEqual(content, open(dest, "rb").read())
+            self.assertEqual(content, f.open().read())
+            self.assertEqual(content, f.open().read())
+
+    def test_file_dest(self):
+        """
+        Similar to test_file, but for a destination object instead of
+        a destination file. This ensures the destination object is being
+        used properly by File.copy, ensuring that other subclasses of Dest
+        will work.
+        """
+        src = self.tmppath("src")
+        dest = MockDest()
+
+        for content in samples:
+            with open(src, "wb") as tmp:
+                tmp.write(content)
+            f = File(src)
+            f.copy(dest)
+            self.assertEqual(content, dest.getvalue())
+
+    def test_file_open(self):
+        """
+        Test whether File.open returns an appropriately reset file object.
+        """
+        src = self.tmppath("src")
+        content = b"".join(samples)
+        with open(src, "wb") as tmp:
+            tmp.write(content)
+
+        f = File(src)
+        self.assertEqual(content[:42], f.open().read(42))
+        self.assertEqual(content, f.open().read())
+
+    def test_file_no_write(self):
+        """
+        Test various conditions where File.copy is expected not to write
+        in the destination file.
+        """
+        src = self.tmppath("src")
+        dest = self.tmppath("dest")
+
+        with open(src, "wb") as tmp:
+            tmp.write(b"test")
+
+        # Initial copy
+        f = File(src)
+        f.copy(dest)
+
+        # Ensure subsequent copies won't trigger writes
+        f.copy(DestNoWrite(dest))
+        self.assertEqual(b"test", open(dest, "rb").read())
+
+        # When the source file is newer, but with the same content, no copy
+        # should occur
+        time = os.path.getmtime(src) - 1
+        os.utime(dest, (time, time))
+        f.copy(DestNoWrite(dest))
+        self.assertEqual(b"test", open(dest, "rb").read())
+
+        # When the source file is older than the destination file, even with
+        # different content, no copy should occur.
+        with open(src, "wb") as tmp:
+            tmp.write(b"fooo")
+        time = os.path.getmtime(dest) - 1
+        os.utime(src, (time, time))
+        f.copy(DestNoWrite(dest))
+        self.assertEqual(b"test", open(dest, "rb").read())
+
+        # Double check that under conditions where a copy occurs, we would get
+        # an exception.
+        time = os.path.getmtime(src) - 1
+        os.utime(dest, (time, time))
+        self.assertRaises(RuntimeError, f.copy, DestNoWrite(dest))
+
+        # skip_if_older=False is expected to force a copy in this situation.
+        f.copy(dest, skip_if_older=False)
+        self.assertEqual(b"fooo", open(dest, "rb").read())
+
+
+class TestAbsoluteSymlinkFile(TestWithTmpDir):
+    def test_absolute_relative(self):
+        AbsoluteSymlinkFile("/foo")
+
+        with self.assertRaisesRegexp(ValueError, "Symlink target not absolute"):
+            AbsoluteSymlinkFile("./foo")
+
+    def test_symlink_file(self):
+        source = self.tmppath("test_path")
+        with open(source, "wt") as fh:
+            fh.write("Hello world")
+
+        s = AbsoluteSymlinkFile(source)
+        dest = self.tmppath("symlink")
+        self.assertTrue(s.copy(dest))
+
+        if self.symlink_supported:
+            self.assertTrue(os.path.islink(dest))
+            link = os.readlink(dest)
+            self.assertEqual(link, source)
+        else:
+            self.assertTrue(os.path.isfile(dest))
+            content = open(dest).read()
+            self.assertEqual(content, "Hello world")
+
+    def test_replace_file_with_symlink(self):
+        # If symlinks are supported, an existing file should be replaced by a
+        # symlink.
+        source = self.tmppath("test_path")
+        with open(source, "wt") as fh:
+            fh.write("source")
+
+        dest = self.tmppath("dest")
+        with open(dest, "a"):
+            pass
+
+        s = AbsoluteSymlinkFile(source)
+        s.copy(dest, skip_if_older=False)
+
+        if self.symlink_supported:
+            self.assertTrue(os.path.islink(dest))
+            link = os.readlink(dest)
+            self.assertEqual(link, source)
+        else:
+            self.assertTrue(os.path.isfile(dest))
+            content = open(dest).read()
+            self.assertEqual(content, "source")
+
+    def test_replace_symlink(self):
+        if not self.symlink_supported:
+            return
+
+        source = self.tmppath("source")
+        with open(source, "a"):
+            pass
+
+        dest = self.tmppath("dest")
+
+        os.symlink(self.tmppath("bad"), dest)
+        self.assertTrue(os.path.islink(dest))
+
+        s = AbsoluteSymlinkFile(source)
+        self.assertTrue(s.copy(dest))
+
+        self.assertTrue(os.path.islink(dest))
+        link = os.readlink(dest)
+        self.assertEqual(link, source)
+
+    def test_noop(self):
+        if not hasattr(os, "symlink") or sys.platform == "win32":
+            return
+
+        source = self.tmppath("source")
+        dest = self.tmppath("dest")
+
+        with open(source, "a"):
+            pass
+
+        os.symlink(source, dest)
+        link = os.readlink(dest)
+        self.assertEqual(link, source)
+
+        s = AbsoluteSymlinkFile(source)
+        self.assertFalse(s.copy(dest))
+
+        link = os.readlink(dest)
+        self.assertEqual(link, source)
+
+
+class TestHardlinkFile(TestWithTmpDir):
+    def test_absolute_relative(self):
+        HardlinkFile("/foo")
+        HardlinkFile("./foo")
+
+    def test_hardlink_file(self):
+        source = self.tmppath("test_path")
+        with open(source, "wt") as fh:
+            fh.write("Hello world")
+
+        s = HardlinkFile(source)
+        dest = self.tmppath("hardlink")
+        self.assertTrue(s.copy(dest))
+
+        if self.hardlink_supported:
+            source_stat = os.stat(source)
+            dest_stat = os.stat(dest)
+            self.assertEqual(source_stat.st_dev, dest_stat.st_dev)
+            self.assertEqual(source_stat.st_ino, dest_stat.st_ino)
+        else:
+            self.assertTrue(os.path.isfile(dest))
+            with open(dest) as f:
+                content = f.read()
+            self.assertEqual(content, "Hello world")
+
+    def test_replace_file_with_hardlink(self):
+        # If hardlink are supported, an existing file should be replaced by a
+        # symlink.
+        source = self.tmppath("test_path")
+        with open(source, "wt") as fh:
+            fh.write("source")
+
+        dest = self.tmppath("dest")
+        with open(dest, "a"):
+            pass
+
+        s = HardlinkFile(source)
+        s.copy(dest, skip_if_older=False)
+
+        if self.hardlink_supported:
+            source_stat = os.stat(source)
+            dest_stat = os.stat(dest)
+            self.assertEqual(source_stat.st_dev, dest_stat.st_dev)
+            self.assertEqual(source_stat.st_ino, dest_stat.st_ino)
+        else:
+            self.assertTrue(os.path.isfile(dest))
+            with open(dest) as f:
+                content = f.read()
+            self.assertEqual(content, "source")
+
+    def test_replace_hardlink(self):
+        if not self.hardlink_supported:
+            raise unittest.SkipTest("hardlink not supported")
+
+        source = self.tmppath("source")
+        with open(source, "a"):
+            pass
+
+        dest = self.tmppath("dest")
+
+        os.link(source, dest)
+
+        s = HardlinkFile(source)
+        self.assertFalse(s.copy(dest))
+
+        source_stat = os.lstat(source)
+        dest_stat = os.lstat(dest)
+        self.assertEqual(source_stat.st_dev, dest_stat.st_dev)
+        self.assertEqual(source_stat.st_ino, dest_stat.st_ino)
+
+    def test_noop(self):
+        if not self.hardlink_supported:
+            raise unittest.SkipTest("hardlink not supported")
+
+        source = self.tmppath("source")
+        dest = self.tmppath("dest")
+
+        with open(source, "a"):
+            pass
+
+        os.link(source, dest)
+
+        s = HardlinkFile(source)
+        self.assertFalse(s.copy(dest))
+
+        source_stat = os.lstat(source)
+        dest_stat = os.lstat(dest)
+        self.assertEqual(source_stat.st_dev, dest_stat.st_dev)
+        self.assertEqual(source_stat.st_ino, dest_stat.st_ino)
+
+
+class TestPreprocessedFile(TestWithTmpDir):
+    def test_preprocess(self):
+        """
+        Test that copying the file invokes the preprocessor
+        """
+        src = self.tmppath("src")
+        dest = self.tmppath("dest")
+
+        with open(src, "wb") as tmp:
+            tmp.write(b"#ifdef FOO\ntest\n#endif")
+
+        f = PreprocessedFile(src, depfile_path=None, marker="#", defines={"FOO": True})
+        self.assertTrue(f.copy(dest))
+
+        self.assertEqual(b"test\n", open(dest, "rb").read())
+
+    def test_preprocess_file_no_write(self):
+        """
+        Test various conditions where PreprocessedFile.copy is expected not to
+        write in the destination file.
+        """
+        src = self.tmppath("src")
+        dest = self.tmppath("dest")
+        depfile = self.tmppath("depfile")
+
+        with open(src, "wb") as tmp:
+            tmp.write(b"#ifdef FOO\ntest\n#endif")
+
+        # Initial copy
+        f = PreprocessedFile(
+            src, depfile_path=depfile, marker="#", defines={"FOO": True}
+        )
+        self.assertTrue(f.copy(dest))
+
+        # Ensure subsequent copies won't trigger writes
+        self.assertFalse(f.copy(DestNoWrite(dest)))
+        self.assertEqual(b"test\n", open(dest, "rb").read())
+
+        # When the source file is older than the destination file, even with
+        # different content, no copy should occur.
+        with open(src, "wb") as tmp:
+            tmp.write(b"#ifdef FOO\nfooo\n#endif")
+        time = os.path.getmtime(dest) - 1
+        os.utime(src, (time, time))
+        self.assertFalse(f.copy(DestNoWrite(dest)))
+        self.assertEqual(b"test\n", open(dest, "rb").read())
+
+        # skip_if_older=False is expected to force a copy in this situation.
+        self.assertTrue(f.copy(dest, skip_if_older=False))
+        self.assertEqual(b"fooo\n", open(dest, "rb").read())
+
+    def test_preprocess_file_dependencies(self):
+        """
+        Test that the preprocess runs if the dependencies of the source change
+        """
+        src = self.tmppath("src")
+        dest = self.tmppath("dest")
+        incl = self.tmppath("incl")
+        deps = self.tmppath("src.pp")
+
+        with open(src, "wb") as tmp:
+            tmp.write(b"#ifdef FOO\ntest\n#endif")
+
+        with open(incl, "wb") as tmp:
+            tmp.write(b"foo bar")
+
+        # Initial copy
+        f = PreprocessedFile(src, depfile_path=deps, marker="#", defines={"FOO": True})
+        self.assertTrue(f.copy(dest))
+
+        # Update the source so it #includes the include file.
+        with open(src, "wb") as tmp:
+            tmp.write(b"#include incl\n")
+        time = os.path.getmtime(dest) + 1
+        os.utime(src, (time, time))
+        self.assertTrue(f.copy(dest))
+        self.assertEqual(b"foo bar", open(dest, "rb").read())
+
+        # If one of the dependencies changes, the file should be updated. The
+        # mtime of the dependency is set after the destination file, to avoid
+        # both files having the same time.
+        with open(incl, "wb") as tmp:
+            tmp.write(b"quux")
+        time = os.path.getmtime(dest) + 1
+        os.utime(incl, (time, time))
+        self.assertTrue(f.copy(dest))
+        self.assertEqual(b"quux", open(dest, "rb").read())
+
+        # Perform one final copy to confirm that we don't run the preprocessor
+        # again. We update the mtime of the destination so it's newer than the
+        # input files. This would "just work" if we weren't changing
+        time = os.path.getmtime(incl) + 1
+        os.utime(dest, (time, time))
+        self.assertFalse(f.copy(DestNoWrite(dest)))
+
+    def test_replace_symlink(self):
+        """
+        Test that if the destination exists, and is a symlink, the target of
+        the symlink is not overwritten by the preprocessor output.
+        """
+        if not self.symlink_supported:
+            return
+
+        source = self.tmppath("source")
+        dest = self.tmppath("dest")
+        pp_source = self.tmppath("pp_in")
+        deps = self.tmppath("deps")
+
+        with open(source, "a"):
+            pass
+
+        os.symlink(source, dest)
+        self.assertTrue(os.path.islink(dest))
+
+        with open(pp_source, "wb") as tmp:
+            tmp.write(b"#define FOO\nPREPROCESSED")
+
+        f = PreprocessedFile(
+            pp_source, depfile_path=deps, marker="#", defines={"FOO": True}
+        )
+        self.assertTrue(f.copy(dest))
+
+        self.assertEqual(b"PREPROCESSED", open(dest, "rb").read())
+        self.assertFalse(os.path.islink(dest))
+        self.assertEqual(b"", open(source, "rb").read())
+
+
+class TestExistingFile(TestWithTmpDir):
+    def test_required_missing_dest(self):
+        with self.assertRaisesRegexp(ErrorMessage, "Required existing file"):
+            f = ExistingFile(required=True)
+            f.copy(self.tmppath("dest"))
+
+    def test_required_existing_dest(self):
+        p = self.tmppath("dest")
+        with open(p, "a"):
+            pass
+
+        f = ExistingFile(required=True)
+        f.copy(p)
+
+    def test_optional_missing_dest(self):
+        f = ExistingFile(required=False)
+        f.copy(self.tmppath("dest"))
+
+    def test_optional_existing_dest(self):
+        p = self.tmppath("dest")
+        with open(p, "a"):
+            pass
+
+        f = ExistingFile(required=False)
+        f.copy(p)
+
+
+class TestGeneratedFile(TestWithTmpDir):
+    def test_generated_file(self):
+        """
+        Check that GeneratedFile.copy yields the proper content in the
+        destination file in all situations that trigger different code paths
+        (see TestFile.test_file)
+        """
+        dest = self.tmppath("dest")
+
+        for content in samples:
+            f = GeneratedFile(content)
+            f.copy(dest)
+            self.assertEqual(content, open(dest, "rb").read())
+
+    def test_generated_file_open(self):
+        """
+        Test whether GeneratedFile.open returns an appropriately reset file
+        object.
+        """
+        content = b"".join(samples)
+        f = GeneratedFile(content)
+        self.assertEqual(content[:42], f.open().read(42))
+        self.assertEqual(content, f.open().read())
+
+    def test_generated_file_no_write(self):
+        """
+        Test various conditions where GeneratedFile.copy is expected not to
+        write in the destination file.
+        """
+        dest = self.tmppath("dest")
+
+        # Initial copy
+        f = GeneratedFile(b"test")
+        f.copy(dest)
+
+        # Ensure subsequent copies won't trigger writes
+        f.copy(DestNoWrite(dest))
+        self.assertEqual(b"test", open(dest, "rb").read())
+
+        # When using a new instance with the same content, no copy should occur
+        f = GeneratedFile(b"test")
+        f.copy(DestNoWrite(dest))
+        self.assertEqual(b"test", open(dest, "rb").read())
+
+        # Double check that under conditions where a copy occurs, we would get
+        # an exception.
+        f = GeneratedFile(b"fooo")
+        self.assertRaises(RuntimeError, f.copy, DestNoWrite(dest))
+
+    def test_generated_file_function(self):
+        """
+        Test GeneratedFile behavior with functions.
+        """
+        dest = self.tmppath("dest")
+        data = {
+            "num_calls": 0,
+        }
+
+        def content():
+            data["num_calls"] += 1
+            return b"content"
+
+        f = GeneratedFile(content)
+        self.assertEqual(data["num_calls"], 0)
+        f.copy(dest)
+        self.assertEqual(data["num_calls"], 1)
+        self.assertEqual(b"content", open(dest, "rb").read())
+        self.assertEqual(b"content", f.open().read())
+        self.assertEqual(b"content", f.read())
+        self.assertEqual(len(b"content"), f.size())
+        self.assertEqual(data["num_calls"], 1)
+
+        f.content = b"modified"
+        f.copy(dest)
+        self.assertEqual(data["num_calls"], 1)
+        self.assertEqual(b"modified", open(dest, "rb").read())
+        self.assertEqual(b"modified", f.open().read())
+        self.assertEqual(b"modified", f.read())
+        self.assertEqual(len(b"modified"), f.size())
+
+        f.content = content
+        self.assertEqual(data["num_calls"], 1)
+        self.assertEqual(b"content", f.read())
+        self.assertEqual(data["num_calls"], 2)
+
+
+class TestDeflatedFile(TestWithTmpDir):
+    def test_deflated_file(self):
+        """
+        Check that DeflatedFile.copy yields the proper content in the
+        destination file in all situations that trigger different code paths
+        (see TestFile.test_file)
+        """
+        src = self.tmppath("src.jar")
+        dest = self.tmppath("dest")
+
+        contents = {}
+        with JarWriter(src) as jar:
+            for content in samples:
+                name = "".join(
+                    random.choice(
+                        "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
+                    )
+                    for i in range(8)
+                )
+                jar.add(name, content, compress=True)
+                contents[name] = content
+
+        for j in JarReader(src):
+            f = DeflatedFile(j)
+            f.copy(dest)
+            self.assertEqual(contents[j.filename], open(dest, "rb").read())
+
+    def test_deflated_file_open(self):
+        """
+        Test whether DeflatedFile.open returns an appropriately reset file
+        object.
+        """
+        src = self.tmppath("src.jar")
+        content = b"".join(samples)
+        with JarWriter(src) as jar:
+            jar.add("content", content)
+
+        f = DeflatedFile(JarReader(src)["content"])
+        self.assertEqual(content[:42], f.open().read(42))
+        self.assertEqual(content, f.open().read())
+
+    def test_deflated_file_no_write(self):
+        """
+        Test various conditions where DeflatedFile.copy is expected not to
+        write in the destination file.
+        """
+        src = self.tmppath("src.jar")
+        dest = self.tmppath("dest")
+
+        with JarWriter(src) as jar:
+            jar.add("test", b"test")
+            jar.add("test2", b"test")
+            jar.add("fooo", b"fooo")
+
+        jar = JarReader(src)
+        # Initial copy
+        f = DeflatedFile(jar["test"])
+        f.copy(dest)
+
+        # Ensure subsequent copies won't trigger writes
+        f.copy(DestNoWrite(dest))
+        self.assertEqual(b"test", open(dest, "rb").read())
+
+        # When using a different file with the same content, no copy should
+        # occur
+        f = DeflatedFile(jar["test2"])
+        f.copy(DestNoWrite(dest))
+        self.assertEqual(b"test", open(dest, "rb").read())
+
+        # Double check that under conditions where a copy occurs, we would get
+        # an exception.
+        f = DeflatedFile(jar["fooo"])
+        self.assertRaises(RuntimeError, f.copy, DestNoWrite(dest))
+
+
+class TestManifestFile(TestWithTmpDir):
+    def test_manifest_file(self):
+        f = ManifestFile("chrome")
+        f.add(ManifestContent("chrome", "global", "toolkit/content/global/"))
+        f.add(ManifestResource("chrome", "gre-resources", "toolkit/res/"))
+        f.add(ManifestResource("chrome/pdfjs", "pdfjs", "./"))
+        f.add(ManifestContent("chrome/pdfjs", "pdfjs", "pdfjs"))
+        f.add(ManifestLocale("chrome", "browser", "en-US", "en-US/locale/browser/"))
+
+        f.copy(self.tmppath("chrome.manifest"))
+        self.assertEqual(
+            open(self.tmppath("chrome.manifest")).readlines(),
+            [
+                "content global toolkit/content/global/\n",
+                "resource gre-resources toolkit/res/\n",
+                "resource pdfjs pdfjs/\n",
+                "content pdfjs pdfjs/pdfjs\n",
+                "locale browser en-US en-US/locale/browser/\n",
+            ],
+        )
+
+        self.assertRaises(
+            ValueError,
+            f.remove,
+            ManifestContent("", "global", "toolkit/content/global/"),
+        )
+        self.assertRaises(
+            ValueError,
+            f.remove,
+            ManifestOverride(
+                "chrome",
+                "chrome://global/locale/netError.dtd",
+                "chrome://browser/locale/netError.dtd",
+            ),
+        )
+
+        f.remove(ManifestContent("chrome", "global", "toolkit/content/global/"))
+        self.assertRaises(
+            ValueError,
+            f.remove,
+            ManifestContent("chrome", "global", "toolkit/content/global/"),
+        )
+
+        f.copy(self.tmppath("chrome.manifest"))
+        content = open(self.tmppath("chrome.manifest"), "rb").read()
+        self.assertEqual(content[:42], f.open().read(42))
+        self.assertEqual(content, f.open().read())
+
+
+# Compiled typelib for the following IDL:
+#     interface foo;
+#     [scriptable, uuid(5f70da76-519c-4858-b71e-e3c92333e2d6)]
+#     interface bar {
+#         void bar(in foo f);
+#     };
+# We need to make this [scriptable] so it doesn't get deleted from the
+# typelib.  We don't need to make the foo interfaces below [scriptable],
+# because they will be automatically included by virtue of being an
+# argument to a method of |bar|.
+bar_xpt = GeneratedFile(
+    b"\x58\x50\x43\x4F\x4D\x0A\x54\x79\x70\x65\x4C\x69\x62\x0D\x0A\x1A"
+    + b"\x01\x02\x00\x02\x00\x00\x00\x7B\x00\x00\x00\x24\x00\x00\x00\x5C"
+    + b"\x80\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00"
+    + b"\x00\x00\x00\x00\x00\x00\x01\x00\x00\x00\x00\x00\x00\x00\x00\x5F"
+    + b"\x70\xDA\x76\x51\x9C\x48\x58\xB7\x1E\xE3\xC9\x23\x33\xE2\xD6\x00"
+    + b"\x00\x00\x05\x00\x00\x00\x00\x00\x00\x00\x0D\x00\x66\x6F\x6F\x00"
+    + b"\x62\x61\x72\x00\x62\x61\x72\x00\x00\x00\x00\x01\x00\x00\x00\x00"
+    + b"\x09\x01\x80\x92\x00\x01\x80\x06\x00\x00\x80"
+)
+
+# Compiled typelib for the following IDL:
+#     [uuid(3271bebc-927e-4bef-935e-44e0aaf3c1e5)]
+#     interface foo {
+#         void foo();
+#     };
+foo_xpt = GeneratedFile(
+    b"\x58\x50\x43\x4F\x4D\x0A\x54\x79\x70\x65\x4C\x69\x62\x0D\x0A\x1A"
+    + b"\x01\x02\x00\x01\x00\x00\x00\x57\x00\x00\x00\x24\x00\x00\x00\x40"
+    + b"\x80\x00\x00\x32\x71\xBE\xBC\x92\x7E\x4B\xEF\x93\x5E\x44\xE0\xAA"
+    + b"\xF3\xC1\xE5\x00\x00\x00\x01\x00\x00\x00\x00\x00\x00\x00\x09\x00"
+    + b"\x66\x6F\x6F\x00\x66\x6F\x6F\x00\x00\x00\x00\x01\x00\x00\x00\x00"
+    + b"\x05\x00\x80\x06\x00\x00\x00"
+)
+
+# Compiled typelib for the following IDL:
+#     [uuid(7057f2aa-fdc2-4559-abde-08d939f7e80d)]
+#     interface foo {
+#         void foo();
+#     };
+foo2_xpt = GeneratedFile(
+    b"\x58\x50\x43\x4F\x4D\x0A\x54\x79\x70\x65\x4C\x69\x62\x0D\x0A\x1A"
+    + b"\x01\x02\x00\x01\x00\x00\x00\x57\x00\x00\x00\x24\x00\x00\x00\x40"
+    + b"\x80\x00\x00\x70\x57\xF2\xAA\xFD\xC2\x45\x59\xAB\xDE\x08\xD9\x39"
+    + b"\xF7\xE8\x0D\x00\x00\x00\x01\x00\x00\x00\x00\x00\x00\x00\x09\x00"
+    + b"\x66\x6F\x6F\x00\x66\x6F\x6F\x00\x00\x00\x00\x01\x00\x00\x00\x00"
+    + b"\x05\x00\x80\x06\x00\x00\x00"
+)
+
+
+class TestMinifiedCommentStripped(TestWithTmpDir):
+    def test_minified_comment_stripped(self):
+        propLines = [
+            "# Comments are removed",
+            "foo = bar",
+            "",
+            "# Another comment",
+        ]
+        prop = GeneratedFile("\n".join(propLines))
+        self.assertEqual(
+            MinifiedCommentStripped(prop).open().readlines(), [b"foo = bar\n", b"\n"]
+        )
+        open(self.tmppath("prop"), "w").write("\n".join(propLines))
+        MinifiedCommentStripped(File(self.tmppath("prop"))).copy(self.tmppath("prop2"))
+        self.assertEqual(open(self.tmppath("prop2")).readlines(), ["foo = bar\n", "\n"])
+
+
+class TestMinifiedJavaScript(TestWithTmpDir):
+    orig_lines = [
+        "// Comment line",
+        'let foo = "bar";',
+        "var bar = true;",
+        "",
+        "// Another comment",
+    ]
+
+    def test_minified_javascript(self):
+        orig_f = GeneratedFile("\n".join(self.orig_lines))
+        min_f = MinifiedJavaScript(orig_f)
+
+        mini_lines = min_f.open().readlines()
+        self.assertTrue(mini_lines)
+        self.assertTrue(len(mini_lines) < len(self.orig_lines))
+
+    def _verify_command(self, code):
+        our_dir = os.path.abspath(os.path.dirname(__file__))
+        return [
+            sys.executable,
+            os.path.join(our_dir, "support", "minify_js_verify.py"),
+            code,
+        ]
+
+    def test_minified_verify_success(self):
+        orig_f = GeneratedFile("\n".join(self.orig_lines))
+        min_f = MinifiedJavaScript(orig_f, verify_command=self._verify_command("0"))
+
+        mini_lines = [six.ensure_text(s) for s in min_f.open().readlines()]
+        self.assertTrue(mini_lines)
+        self.assertTrue(len(mini_lines) < len(self.orig_lines))
+
+    def test_minified_verify_failure(self):
+        orig_f = GeneratedFile("\n".join(self.orig_lines))
+        errors.out = six.StringIO()
+        min_f = MinifiedJavaScript(orig_f, verify_command=self._verify_command("1"))
+
+        mini_lines = min_f.open().readlines()
+        output = errors.out.getvalue()
+        errors.out = sys.stderr
+        self.assertEqual(
+            output,
+            "warning: JS minification verification failed for <unknown>:\n"
+            "warning: Error message\n",
+        )
+        self.assertEqual(mini_lines, orig_f.open().readlines())
+
+
+class MatchTestTemplate(object):
+    def prepare_match_test(self, with_dotfiles=False):
+        self.add("bar")
+        self.add("foo/bar")
+        self.add("foo/baz")
+        self.add("foo/qux/1")
+        self.add("foo/qux/bar")
+        self.add("foo/qux/2/test")
+        self.add("foo/qux/2/test2")
+        if with_dotfiles:
+            self.add("foo/.foo")
+            self.add("foo/.bar/foo")
+
+    def do_match_test(self):
+        self.do_check(
+            "",
+            [
+                "bar",
+                "foo/bar",
+                "foo/baz",
+                "foo/qux/1",
+                "foo/qux/bar",
+                "foo/qux/2/test",
+                "foo/qux/2/test2",
+            ],
+        )
+        self.do_check(
+            "*",
+            [
+                "bar",
+                "foo/bar",
+                "foo/baz",
+                "foo/qux/1",
+                "foo/qux/bar",
+                "foo/qux/2/test",
+                "foo/qux/2/test2",
+            ],
+        )
+        self.do_check(
+            "foo/qux", ["foo/qux/1", "foo/qux/bar", "foo/qux/2/test", "foo/qux/2/test2"]
+        )
+        self.do_check("foo/b*", ["foo/bar", "foo/baz"])
+        self.do_check("baz", [])
+        self.do_check("foo/foo", [])
+        self.do_check("foo/*ar", ["foo/bar"])
+        self.do_check("*ar", ["bar"])
+        self.do_check("*/bar", ["foo/bar"])
+        self.do_check(
+            "foo/*ux", ["foo/qux/1", "foo/qux/bar", "foo/qux/2/test", "foo/qux/2/test2"]
+        )
+        self.do_check(
+            "foo/q*ux",
+            ["foo/qux/1", "foo/qux/bar", "foo/qux/2/test", "foo/qux/2/test2"],
+        )
+        self.do_check("foo/*/2/test*", ["foo/qux/2/test", "foo/qux/2/test2"])
+        self.do_check("**/bar", ["bar", "foo/bar", "foo/qux/bar"])
+        self.do_check("foo/**/test", ["foo/qux/2/test"])
+        self.do_check(
+            "foo",
+            [
+                "foo/bar",
+                "foo/baz",
+                "foo/qux/1",
+                "foo/qux/bar",
+                "foo/qux/2/test",
+                "foo/qux/2/test2",
+            ],
+        )
+        self.do_check(
+            "foo/**",
+            [
+                "foo/bar",
+                "foo/baz",
+                "foo/qux/1",
+                "foo/qux/bar",
+                "foo/qux/2/test",
+                "foo/qux/2/test2",
+            ],
+        )
+        self.do_check("**/2/test*", ["foo/qux/2/test", "foo/qux/2/test2"])
+        self.do_check(
+            "**/foo",
+            [
+                "foo/bar",
+                "foo/baz",
+                "foo/qux/1",
+                "foo/qux/bar",
+                "foo/qux/2/test",
+                "foo/qux/2/test2",
+            ],
+        )
+        self.do_check("**/barbaz", [])
+        self.do_check("f**/bar", ["foo/bar"])
+
+    def do_finder_test(self, finder):
+        self.assertTrue(finder.contains("foo/.foo"))
+        self.assertTrue(finder.contains("foo/.bar"))
+        self.assertTrue("foo/.foo" in [f for f, c in finder.find("foo/.foo")])
+        self.assertTrue("foo/.bar/foo" in [f for f, c in finder.find("foo/.bar")])
+        self.assertEqual(
+            sorted([f for f, c in finder.find("foo/.*")]), ["foo/.bar/foo", "foo/.foo"]
+        )
+        for pattern in ["foo", "**", "**/*", "**/foo", "foo/*"]:
+            self.assertFalse("foo/.foo" in [f for f, c in finder.find(pattern)])
+            self.assertFalse("foo/.bar/foo" in [f for f, c in finder.find(pattern)])
+            self.assertEqual(
+                sorted([f for f, c in finder.find(pattern)]),
+                sorted([f for f, c in finder if mozpath.match(f, pattern)]),
+            )
+
+
+def do_check(test, finder, pattern, result):
+    if result:
+        test.assertTrue(finder.contains(pattern))
+    else:
+        test.assertFalse(finder.contains(pattern))
+    test.assertEqual(sorted(list(f for f, c in finder.find(pattern))), sorted(result))
+
+
+class TestFileFinder(MatchTestTemplate, TestWithTmpDir):
+    def add(self, path):
+        ensureParentDir(self.tmppath(path))
+        open(self.tmppath(path), "wb").write(six.ensure_binary(path))
+
+    def do_check(self, pattern, result):
+        do_check(self, self.finder, pattern, result)
+
+    def test_file_finder(self):
+        self.prepare_match_test(with_dotfiles=True)
+        self.finder = FileFinder(self.tmpdir)
+        self.do_match_test()
+        self.do_finder_test(self.finder)
+
+    def test_get(self):
+        self.prepare_match_test()
+        finder = FileFinder(self.tmpdir)
+
+        self.assertIsNone(finder.get("does-not-exist"))
+        res = finder.get("bar")
+        self.assertIsInstance(res, File)
+        self.assertEqual(mozpath.normpath(res.path), mozpath.join(self.tmpdir, "bar"))
+
+    def test_ignored_dirs(self):
+        """Ignored directories should not have results returned."""
+        self.prepare_match_test()
+        self.add("fooz")
+
+        # Present to ensure prefix matching doesn't exclude.
+        self.add("foo/quxz")
+
+        self.finder = FileFinder(self.tmpdir, ignore=["foo/qux"])
+
+        self.do_check("**", ["bar", "foo/bar", "foo/baz", "foo/quxz", "fooz"])
+        self.do_check("foo/*", ["foo/bar", "foo/baz", "foo/quxz"])
+        self.do_check("foo/**", ["foo/bar", "foo/baz", "foo/quxz"])
+        self.do_check("foo/qux/**", [])
+        self.do_check("foo/qux/*", [])
+        self.do_check("foo/qux/bar", [])
+        self.do_check("foo/quxz", ["foo/quxz"])
+        self.do_check("fooz", ["fooz"])
+
+    def test_ignored_files(self):
+        """Ignored files should not have results returned."""
+        self.prepare_match_test()
+
+        # Be sure prefix match doesn't get ignored.
+        self.add("barz")
+
+        self.finder = FileFinder(self.tmpdir, ignore=["foo/bar", "bar"])
+        self.do_check(
+            "**",
+            [
+                "barz",
+                "foo/baz",
+                "foo/qux/1",
+                "foo/qux/2/test",
+                "foo/qux/2/test2",
+                "foo/qux/bar",
+            ],
+        )
+        self.do_check(
+            "foo/**",
+            [
+                "foo/baz",
+                "foo/qux/1",
+                "foo/qux/2/test",
+                "foo/qux/2/test2",
+                "foo/qux/bar",
+            ],
+        )
+
+    def test_ignored_patterns(self):
+        """Ignore entries with patterns should be honored."""
+        self.prepare_match_test()
+
+        self.add("foo/quxz")
+
+        self.finder = FileFinder(self.tmpdir, ignore=["foo/qux/*"])
+        self.do_check("**", ["foo/bar", "foo/baz", "foo/quxz", "bar"])
+        self.do_check("foo/**", ["foo/bar", "foo/baz", "foo/quxz"])
+
+    def test_dotfiles(self):
+        """Finder can find files beginning with . is configured."""
+        self.prepare_match_test(with_dotfiles=True)
+        self.finder = FileFinder(self.tmpdir, find_dotfiles=True)
+        self.do_check(
+            "**",
+            [
+                "bar",
+                "foo/.foo",
+                "foo/.bar/foo",
+                "foo/bar",
+                "foo/baz",
+                "foo/qux/1",
+                "foo/qux/bar",
+                "foo/qux/2/test",
+                "foo/qux/2/test2",
+            ],
+        )
+
+    def test_dotfiles_plus_ignore(self):
+        self.prepare_match_test(with_dotfiles=True)
+        self.finder = FileFinder(
+            self.tmpdir, find_dotfiles=True, ignore=["foo/.bar/**"]
+        )
+        self.do_check(
+            "foo/**",
+            [
+                "foo/.foo",
+                "foo/bar",
+                "foo/baz",
+                "foo/qux/1",
+                "foo/qux/bar",
+                "foo/qux/2/test",
+                "foo/qux/2/test2",
+            ],
+        )
+
+
+class TestJarFinder(MatchTestTemplate, TestWithTmpDir):
+    def add(self, path):
+        self.jar.add(path, ensure_bytes(path), compress=True)
+
+    def do_check(self, pattern, result):
+        do_check(self, self.finder, pattern, result)
+
+    def test_jar_finder(self):
+        self.jar = JarWriter(file=self.tmppath("test.jar"))
+        self.prepare_match_test()
+        self.jar.finish()
+        reader = JarReader(file=self.tmppath("test.jar"))
+        self.finder = JarFinder(self.tmppath("test.jar"), reader)
+        self.do_match_test()
+
+        self.assertIsNone(self.finder.get("does-not-exist"))
+        self.assertIsInstance(self.finder.get("bar"), DeflatedFile)
+
+
+class TestTarFinder(MatchTestTemplate, TestWithTmpDir):
+    def add(self, path):
+        self.tar.addfile(tarfile.TarInfo(name=path))
+
+    def do_check(self, pattern, result):
+        do_check(self, self.finder, pattern, result)
+
+    def test_tar_finder(self):
+        self.tar = tarfile.open(name=self.tmppath("test.tar.bz2"), mode="w:bz2")
+        self.prepare_match_test()
+        self.tar.close()
+        with tarfile.open(name=self.tmppath("test.tar.bz2"), mode="r:bz2") as tarreader:
+            self.finder = TarFinder(self.tmppath("test.tar.bz2"), tarreader)
+            self.do_match_test()
+
+            self.assertIsNone(self.finder.get("does-not-exist"))
+            self.assertIsInstance(self.finder.get("bar"), ExtractedTarFile)
+
+
+class TestComposedFinder(MatchTestTemplate, TestWithTmpDir):
+    def add(self, path, content=None):
+        # Put foo/qux files under $tmp/b.
+        if path.startswith("foo/qux/"):
+            real_path = mozpath.join("b", path[8:])
+        else:
+            real_path = mozpath.join("a", path)
+        ensureParentDir(self.tmppath(real_path))
+        if not content:
+            content = six.ensure_binary(path)
+        open(self.tmppath(real_path), "wb").write(content)
+
+    def do_check(self, pattern, result):
+        if "*" in pattern:
+            return
+        do_check(self, self.finder, pattern, result)
+
+    def test_composed_finder(self):
+        self.prepare_match_test()
+        # Also add files in $tmp/a/foo/qux because ComposedFinder is
+        # expected to mask foo/qux entirely with content from $tmp/b.
+        ensureParentDir(self.tmppath("a/foo/qux/hoge"))
+        open(self.tmppath("a/foo/qux/hoge"), "wb").write(b"hoge")
+        open(self.tmppath("a/foo/qux/bar"), "wb").write(b"not the right content")
+        self.finder = ComposedFinder(
+            {
+                "": FileFinder(self.tmppath("a")),
+                "foo/qux": FileFinder(self.tmppath("b")),
+            }
+        )
+        self.do_match_test()
+
+        self.assertIsNone(self.finder.get("does-not-exist"))
+        self.assertIsInstance(self.finder.get("bar"), File)
+
+
+@unittest.skipUnless(hglib, "hglib not available")
+@unittest.skipIf(
+    six.PY3 and os.name == "nt", "Does not currently work in Python3 on Windows"
+)
+class TestMercurialRevisionFinder(MatchTestTemplate, TestWithTmpDir):
+    def setUp(self):
+        super(TestMercurialRevisionFinder, self).setUp()
+        hglib.init(self.tmpdir)
+        self._clients = []
+
+    def tearDown(self):
+        # Ensure the hg client process is closed. Otherwise, Windows
+        # may have trouble removing the repo directory because the process
+        # has an open handle on it.
+        for client in getattr(self, "_clients", []):
+            if client.server:
+                client.close()
+
+        self._clients[:] = []
+
+        super(TestMercurialRevisionFinder, self).tearDown()
+
+    def _client(self):
+        configs = (
+            # b'' because py2 needs !unicode
+            b'ui.username="Dummy User <dummy@example.com>"',
+        )
+        client = hglib.open(
+            six.ensure_binary(self.tmpdir),
+            encoding=b"UTF-8",  # b'' because py2 needs !unicode
+            configs=configs,
+        )
+        self._clients.append(client)
+        return client
+
+    def add(self, path):
+        with self._client() as c:
+            ensureParentDir(self.tmppath(path))
+            with open(self.tmppath(path), "wb") as fh:
+                fh.write(six.ensure_binary(path))
+            c.add(six.ensure_binary(self.tmppath(path)))
+
+    def do_check(self, pattern, result):
+        do_check(self, self.finder, pattern, result)
+
+    def _get_finder(self, *args, **kwargs):
+        f = MercurialRevisionFinder(*args, **kwargs)
+        self._clients.append(f._client)
+        return f
+
+    def test_default_revision(self):
+        self.prepare_match_test()
+        with self._client() as c:
+            c.commit("initial commit")
+
+        self.finder = self._get_finder(self.tmpdir)
+        self.do_match_test()
+
+        self.assertIsNone(self.finder.get("does-not-exist"))
+        self.assertIsInstance(self.finder.get("bar"), MercurialFile)
+
+    def test_old_revision(self):
+        with self._client() as c:
+            with open(self.tmppath("foo"), "wb") as fh:
+                fh.write(b"foo initial")
+            c.add(six.ensure_binary(self.tmppath("foo")))
+            c.commit("initial")
+
+            with open(self.tmppath("foo"), "wb") as fh:
+                fh.write(b"foo second")
+            with open(self.tmppath("bar"), "wb") as fh:
+                fh.write(b"bar second")
+            c.add(six.ensure_binary(self.tmppath("bar")))
+            c.commit("second")
+            # This wipes out the working directory, ensuring the finder isn't
+            # finding anything from the filesystem.
+            c.rawcommand([b"update", b"null"])
+
+        finder = self._get_finder(self.tmpdir, "0")
+        f = finder.get("foo")
+        self.assertEqual(f.read(), b"foo initial")
+        self.assertEqual(f.read(), b"foo initial", "read again for good measure")
+        self.assertIsNone(finder.get("bar"))
+
+        finder = self._get_finder(self.tmpdir, rev="1")
+        f = finder.get("foo")
+        self.assertEqual(f.read(), b"foo second")
+        f = finder.get("bar")
+        self.assertEqual(f.read(), b"bar second")
+        f = None
+
+    def test_recognize_repo_paths(self):
+        with self._client() as c:
+            with open(self.tmppath("foo"), "wb") as fh:
+                fh.write(b"initial")
+            c.add(six.ensure_binary(self.tmppath("foo")))
+            c.commit("initial")
+            c.rawcommand([b"update", b"null"])
+
+        finder = self._get_finder(self.tmpdir, "0", recognize_repo_paths=True)
+        with self.assertRaises(NotImplementedError):
+            list(finder.find(""))
+
+        with self.assertRaises(ValueError):
+            finder.get("foo")
+        with self.assertRaises(ValueError):
+            finder.get("")
+
+        f = finder.get(self.tmppath("foo"))
+        self.assertIsInstance(f, MercurialFile)
+        self.assertEqual(f.read(), b"initial")
+        f = None
+
+
+if __name__ == "__main__":
+    mozunit.main()
diff --git a/python/mozbuild/mozpack/test/test_manifests.py b/python/mozbuild/mozpack/test/test_manifests.py
new file mode 100644
index 0000000000..a5db53b58c
--- /dev/null
+++ b/python/mozbuild/mozpack/test/test_manifests.py
@@ -0,0 +1,465 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+import os
+
+import mozunit
+
+from mozpack.copier import FileCopier, FileRegistry
+from mozpack.manifests import InstallManifest, UnreadableInstallManifest
+from mozpack.test.test_files import TestWithTmpDir
+
+
+class TestInstallManifest(TestWithTmpDir):
+    def test_construct(self):
+        m = InstallManifest()
+        self.assertEqual(len(m), 0)
+
+    def test_malformed(self):
+        f = self.tmppath("manifest")
+        open(f, "wt").write("junk\n")
+        with self.assertRaises(UnreadableInstallManifest):
+            InstallManifest(f)
+
+    def test_adds(self):
+        m = InstallManifest()
+        m.add_link("s_source", "s_dest")
+        m.add_copy("c_source", "c_dest")
+        m.add_required_exists("e_dest")
+        m.add_optional_exists("o_dest")
+        m.add_pattern_link("ps_base", "ps/*", "ps_dest")
+        m.add_pattern_copy("pc_base", "pc/**", "pc_dest")
+        m.add_preprocess("p_source", "p_dest", "p_source.pp")
+        m.add_content("content", "content")
+
+        self.assertEqual(len(m), 8)
+        self.assertIn("s_dest", m)
+        self.assertIn("c_dest", m)
+        self.assertIn("p_dest", m)
+        self.assertIn("e_dest", m)
+        self.assertIn("o_dest", m)
+        self.assertIn("content", m)
+
+        with self.assertRaises(ValueError):
+            m.add_link("s_other", "s_dest")
+
+        with self.assertRaises(ValueError):
+            m.add_copy("c_other", "c_dest")
+
+        with self.assertRaises(ValueError):
+            m.add_preprocess("p_other", "p_dest", "p_other.pp")
+
+        with self.assertRaises(ValueError):
+            m.add_required_exists("e_dest")
+
+        with self.assertRaises(ValueError):
+            m.add_optional_exists("o_dest")
+
+        with self.assertRaises(ValueError):
+            m.add_pattern_link("ps_base", "ps/*", "ps_dest")
+
+        with self.assertRaises(ValueError):
+            m.add_pattern_copy("pc_base", "pc/**", "pc_dest")
+
+        with self.assertRaises(ValueError):
+            m.add_content("content", "content")
+
+    def _get_test_manifest(self):
+        m = InstallManifest()
+        m.add_link(self.tmppath("s_source"), "s_dest")
+        m.add_copy(self.tmppath("c_source"), "c_dest")
+        m.add_preprocess(
+            self.tmppath("p_source"),
+            "p_dest",
+            self.tmppath("p_source.pp"),
+            "#",
+            {"FOO": "BAR", "BAZ": "QUX"},
+        )
+        m.add_required_exists("e_dest")
+        m.add_optional_exists("o_dest")
+        m.add_pattern_link("ps_base", "*", "ps_dest")
+        m.add_pattern_copy("pc_base", "**", "pc_dest")
+        m.add_content("the content\non\nmultiple lines", "content")
+
+        return m
+
+    def test_serialization(self):
+        m = self._get_test_manifest()
+
+        p = self.tmppath("m")
+        m.write(path=p)
+        self.assertTrue(os.path.isfile(p))
+
+        with open(p, "r") as fh:
+            c = fh.read()
+
+        self.assertEqual(c.count("\n"), 9)
+
+        lines = c.splitlines()
+        self.assertEqual(len(lines), 9)
+
+        self.assertEqual(lines[0], "5")
+
+        m2 = InstallManifest(path=p)
+        self.assertEqual(m, m2)
+        p2 = self.tmppath("m2")
+        m2.write(path=p2)
+
+        with open(p2, "r") as fh:
+            c2 = fh.read()
+
+        self.assertEqual(c, c2)
+
+    def test_populate_registry(self):
+        m = self._get_test_manifest()
+        r = FileRegistry()
+        m.populate_registry(r)
+
+        self.assertEqual(len(r), 6)
+        self.assertEqual(
+            r.paths(), ["c_dest", "content", "e_dest", "o_dest", "p_dest", "s_dest"]
+        )
+
+    def test_pattern_expansion(self):
+        source = self.tmppath("source")
+        os.mkdir(source)
+        os.mkdir("%s/base" % source)
+        os.mkdir("%s/base/foo" % source)
+
+        with open("%s/base/foo/file1" % source, "a"):
+            pass
+
+        with open("%s/base/foo/file2" % source, "a"):
+            pass
+
+        m = InstallManifest()
+        m.add_pattern_link("%s/base" % source, "**", "dest")
+
+        c = FileCopier()
+        m.populate_registry(c)
+        self.assertEqual(c.paths(), ["dest/foo/file1", "dest/foo/file2"])
+
+    def test_write_expand_pattern(self):
+        source = self.tmppath("source")
+        os.mkdir(source)
+        os.mkdir("%s/base" % source)
+        os.mkdir("%s/base/foo" % source)
+
+        with open("%s/base/foo/file1" % source, "a"):
+            pass
+
+        with open("%s/base/foo/file2" % source, "a"):
+            pass
+
+        m = InstallManifest()
+        m.add_pattern_link("%s/base" % source, "**", "dest")
+
+        track = self.tmppath("track")
+        m.write(path=track, expand_pattern=True)
+
+        m = InstallManifest(path=track)
+        self.assertEqual(
+            sorted(dest for dest in m._dests), ["dest/foo/file1", "dest/foo/file2"]
+        )
+
+    def test_or(self):
+        m1 = self._get_test_manifest()
+        orig_length = len(m1)
+        m2 = InstallManifest()
+        m2.add_link("s_source2", "s_dest2")
+        m2.add_copy("c_source2", "c_dest2")
+
+        m1 |= m2
+
+        self.assertEqual(len(m2), 2)
+        self.assertEqual(len(m1), orig_length + 2)
+
+        self.assertIn("s_dest2", m1)
+        self.assertIn("c_dest2", m1)
+
+    def test_copier_application(self):
+        dest = self.tmppath("dest")
+        os.mkdir(dest)
+
+        to_delete = self.tmppath("dest/to_delete")
+        with open(to_delete, "a"):
+            pass
+
+        with open(self.tmppath("s_source"), "wt") as fh:
+            fh.write("symlink!")
+
+        with open(self.tmppath("c_source"), "wt") as fh:
+            fh.write("copy!")
+
+        with open(self.tmppath("p_source"), "wt") as fh:
+            fh.write("#define FOO 1\npreprocess!")
+
+        with open(self.tmppath("dest/e_dest"), "a"):
+            pass
+
+        with open(self.tmppath("dest/o_dest"), "a"):
+            pass
+
+        m = self._get_test_manifest()
+        c = FileCopier()
+        m.populate_registry(c)
+        result = c.copy(dest)
+
+        self.assertTrue(os.path.exists(self.tmppath("dest/s_dest")))
+        self.assertTrue(os.path.exists(self.tmppath("dest/c_dest")))
+        self.assertTrue(os.path.exists(self.tmppath("dest/p_dest")))
+        self.assertTrue(os.path.exists(self.tmppath("dest/e_dest")))
+        self.assertTrue(os.path.exists(self.tmppath("dest/o_dest")))
+        self.assertTrue(os.path.exists(self.tmppath("dest/content")))
+        self.assertFalse(os.path.exists(to_delete))
+
+        with open(self.tmppath("dest/s_dest"), "rt") as fh:
+            self.assertEqual(fh.read(), "symlink!")
+
+        with open(self.tmppath("dest/c_dest"), "rt") as fh:
+            self.assertEqual(fh.read(), "copy!")
+
+        with open(self.tmppath("dest/p_dest"), "rt") as fh:
+            self.assertEqual(fh.read(), "preprocess!")
+
+        self.assertEqual(
+            result.updated_files,
+            set(
+                self.tmppath(p)
+                for p in ("dest/s_dest", "dest/c_dest", "dest/p_dest", "dest/content")
+            ),
+        )
+        self.assertEqual(
+            result.existing_files,
+            set([self.tmppath("dest/e_dest"), self.tmppath("dest/o_dest")]),
+        )
+        self.assertEqual(result.removed_files, {to_delete})
+        self.assertEqual(result.removed_directories, set())
+
+    def test_preprocessor(self):
+        manifest = self.tmppath("m")
+        deps = self.tmppath("m.pp")
+        dest = self.tmppath("dest")
+        include = self.tmppath("p_incl")
+
+        with open(include, "wt") as fh:
+            fh.write("#define INCL\n")
+        time = os.path.getmtime(include) - 3
+        os.utime(include, (time, time))
+
+        with open(self.tmppath("p_source"), "wt") as fh:
+            fh.write("#ifdef FOO\n#if BAZ == QUX\nPASS1\n#endif\n#endif\n")
+            fh.write("#ifdef DEPTEST\nPASS2\n#endif\n")
+            fh.write("#include p_incl\n#ifdef INCLTEST\nPASS3\n#endif\n")
+        time = os.path.getmtime(self.tmppath("p_source")) - 3
+        os.utime(self.tmppath("p_source"), (time, time))
+
+        # Create and write a manifest with the preprocessed file, then apply it.
+        # This should write out our preprocessed file.
+        m = InstallManifest()
+        m.add_preprocess(
+            self.tmppath("p_source"), "p_dest", deps, "#", {"FOO": "BAR", "BAZ": "QUX"}
+        )
+        m.write(path=manifest)
+
+        m = InstallManifest(path=manifest)
+        c = FileCopier()
+        m.populate_registry(c)
+        c.copy(dest)
+
+        self.assertTrue(os.path.exists(self.tmppath("dest/p_dest")))
+
+        with open(self.tmppath("dest/p_dest"), "rt") as fh:
+            self.assertEqual(fh.read(), "PASS1\n")
+
+        # Create a second manifest with the preprocessed file, then apply it.
+        # Since this manifest does not exist on the disk, there should not be a
+        # dependency on it, and the preprocessed file should not be modified.
+        m2 = InstallManifest()
+        m2.add_preprocess(
+            self.tmppath("p_source"), "p_dest", deps, "#", {"DEPTEST": True}
+        )
+        c = FileCopier()
+        m2.populate_registry(c)
+        result = c.copy(dest)
+
+        self.assertFalse(self.tmppath("dest/p_dest") in result.updated_files)
+        self.assertTrue(self.tmppath("dest/p_dest") in result.existing_files)
+
+        # Write out the second manifest, then load it back in from the disk.
+        # This should add the dependency on the manifest file, so our
+        # preprocessed file should be regenerated with the new defines.
+        # We also set the mtime on the destination file back, so it will be
+        # older than the manifest file.
+        m2.write(path=manifest)
+        time = os.path.getmtime(manifest) - 1
+        os.utime(self.tmppath("dest/p_dest"), (time, time))
+        m2 = InstallManifest(path=manifest)
+        c = FileCopier()
+        m2.populate_registry(c)
+        self.assertTrue(c.copy(dest))
+
+        with open(self.tmppath("dest/p_dest"), "rt") as fh:
+            self.assertEqual(fh.read(), "PASS2\n")
+
+        # Set the time on the manifest back, so it won't be picked up as
+        # modified in the next test
+        time = os.path.getmtime(manifest) - 1
+        os.utime(manifest, (time, time))
+
+        # Update the contents of a file included by the source file. This should
+        # cause the destination to be regenerated.
+        with open(include, "wt") as fh:
+            fh.write("#define INCLTEST\n")
+
+        time = os.path.getmtime(include) - 1
+        os.utime(self.tmppath("dest/p_dest"), (time, time))
+        c = FileCopier()
+        m2.populate_registry(c)
+        self.assertTrue(c.copy(dest))
+
+        with open(self.tmppath("dest/p_dest"), "rt") as fh:
+            self.assertEqual(fh.read(), "PASS2\nPASS3\n")
+
+    def test_preprocessor_dependencies(self):
+        manifest = self.tmppath("m")
+        deps = self.tmppath("m.pp")
+        dest = self.tmppath("dest")
+        source = self.tmppath("p_source")
+        destfile = self.tmppath("dest/p_dest")
+        include = self.tmppath("p_incl")
+        os.mkdir(dest)
+
+        with open(source, "wt") as fh:
+            fh.write("#define SRC\nSOURCE\n")
+        time = os.path.getmtime(source) - 3
+        os.utime(source, (time, time))
+
+        with open(include, "wt") as fh:
+            fh.write("INCLUDE\n")
+        time = os.path.getmtime(source) - 3
+        os.utime(include, (time, time))
+
+        # Create and write a manifest with the preprocessed file.
+        m = InstallManifest()
+        m.add_preprocess(source, "p_dest", deps, "#", {"FOO": "BAR", "BAZ": "QUX"})
+        m.write(path=manifest)
+
+        time = os.path.getmtime(source) - 5
+        os.utime(manifest, (time, time))
+
+        # Now read the manifest back in, and apply it. This should write out
+        # our preprocessed file.
+        m = InstallManifest(path=manifest)
+        c = FileCopier()
+        m.populate_registry(c)
+        self.assertTrue(c.copy(dest))
+
+        with open(destfile, "rt") as fh:
+            self.assertEqual(fh.read(), "SOURCE\n")
+
+        # Next, modify the source to #INCLUDE another file.
+        with open(source, "wt") as fh:
+            fh.write("SOURCE\n#include p_incl\n")
+        time = os.path.getmtime(source) - 1
+        os.utime(destfile, (time, time))
+
+        # Apply the manifest, and confirm that it also reads the newly included
+        # file.
+        m = InstallManifest(path=manifest)
+        c = FileCopier()
+        m.populate_registry(c)
+        c.copy(dest)
+
+        with open(destfile, "rt") as fh:
+            self.assertEqual(fh.read(), "SOURCE\nINCLUDE\n")
+
+        # Set the time on the source file back, so it won't be picked up as
+        # modified in the next test.
+        time = os.path.getmtime(source) - 1
+        os.utime(source, (time, time))
+
+        # Now, modify the include file (but not the original source).
+        with open(include, "wt") as fh:
+            fh.write("INCLUDE MODIFIED\n")
+        time = os.path.getmtime(include) - 1
+        os.utime(destfile, (time, time))
+
+        # Apply the manifest, and confirm that the change to the include file
+        # is detected. That should cause the preprocessor to run again.
+        m = InstallManifest(path=manifest)
+        c = FileCopier()
+        m.populate_registry(c)
+        c.copy(dest)
+
+        with open(destfile, "rt") as fh:
+            self.assertEqual(fh.read(), "SOURCE\nINCLUDE MODIFIED\n")
+
+        # ORing an InstallManifest should copy file dependencies
+        m = InstallManifest()
+        m |= InstallManifest(path=manifest)
+        c = FileCopier()
+        m.populate_registry(c)
+        e = c._files["p_dest"]
+        self.assertEqual(e.extra_depends, [manifest])
+
+    def test_add_entries_from(self):
+        source = self.tmppath("source")
+        os.mkdir(source)
+        os.mkdir("%s/base" % source)
+        os.mkdir("%s/base/foo" % source)
+
+        with open("%s/base/foo/file1" % source, "a"):
+            pass
+
+        with open("%s/base/foo/file2" % source, "a"):
+            pass
+
+        m = InstallManifest()
+        m.add_pattern_link("%s/base" % source, "**", "dest")
+
+        p = InstallManifest()
+        p.add_entries_from(m)
+        self.assertEqual(len(p), 1)
+
+        c = FileCopier()
+        p.populate_registry(c)
+        self.assertEqual(c.paths(), ["dest/foo/file1", "dest/foo/file2"])
+
+        q = InstallManifest()
+        q.add_entries_from(m, base="target")
+        self.assertEqual(len(q), 1)
+
+        d = FileCopier()
+        q.populate_registry(d)
+        self.assertEqual(d.paths(), ["target/dest/foo/file1", "target/dest/foo/file2"])
+
+        # Some of the values in an InstallManifest include destination
+        # information that is present in the keys.  Verify that we can
+        # round-trip serialization.
+        r = InstallManifest()
+        r.add_entries_from(m)
+        r.add_entries_from(m, base="target")
+        self.assertEqual(len(r), 2)
+
+        temp_path = self.tmppath("temp_path")
+        r.write(path=temp_path)
+
+        s = InstallManifest(path=temp_path)
+        e = FileCopier()
+        s.populate_registry(e)
+
+        self.assertEqual(
+            e.paths(),
+            [
+                "dest/foo/file1",
+                "dest/foo/file2",
+                "target/dest/foo/file1",
+                "target/dest/foo/file2",
+            ],
+        )
+
+
+if __name__ == "__main__":
+    mozunit.main()
diff --git a/python/mozbuild/mozpack/test/test_mozjar.py b/python/mozbuild/mozpack/test/test_mozjar.py
new file mode 100644
index 0000000000..e96c59238f
--- /dev/null
+++ b/python/mozbuild/mozpack/test/test_mozjar.py
@@ -0,0 +1,350 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+import os
+import unittest
+from collections import OrderedDict
+
+import mozunit
+import six
+
+import mozpack.path as mozpath
+from mozpack.files import FileFinder
+from mozpack.mozjar import (
+    Deflater,
+    JarLog,
+    JarReader,
+    JarReaderError,
+    JarStruct,
+    JarWriter,
+    JarWriterError,
+)
+from mozpack.test.test_files import MockDest
+
+test_data_path = mozpath.abspath(mozpath.dirname(__file__))
+test_data_path = mozpath.join(test_data_path, "data")
+
+
+class TestJarStruct(unittest.TestCase):
+    class Foo(JarStruct):
+        MAGIC = 0x01020304
+        STRUCT = OrderedDict(
+            [
+                ("foo", "uint32"),
+                ("bar", "uint16"),
+                ("qux", "uint16"),
+                ("length", "uint16"),
+                ("length2", "uint16"),
+                ("string", "length"),
+                ("string2", "length2"),
+            ]
+        )
+
+    def test_jar_struct(self):
+        foo = TestJarStruct.Foo()
+        self.assertEqual(foo.signature, TestJarStruct.Foo.MAGIC)
+        self.assertEqual(foo["foo"], 0)
+        self.assertEqual(foo["bar"], 0)
+        self.assertEqual(foo["qux"], 0)
+        self.assertFalse("length" in foo)
+        self.assertFalse("length2" in foo)
+        self.assertEqual(foo["string"], "")
+        self.assertEqual(foo["string2"], "")
+
+        self.assertEqual(foo.size, 16)
+
+        foo["foo"] = 0x42434445
+        foo["bar"] = 0xABCD
+        foo["qux"] = 0xEF01
+        foo["string"] = "abcde"
+        foo["string2"] = "Arbitrarily long string"
+
+        serialized = (
+            b"\x04\x03\x02\x01\x45\x44\x43\x42\xcd\xab\x01\xef"
+            + b"\x05\x00\x17\x00abcdeArbitrarily long string"
+        )
+        self.assertEqual(foo.size, len(serialized))
+        foo_serialized = foo.serialize()
+        self.assertEqual(foo_serialized, serialized)
+
+    def do_test_read_jar_struct(self, data):
+        self.assertRaises(JarReaderError, TestJarStruct.Foo, data)
+        self.assertRaises(JarReaderError, TestJarStruct.Foo, data[2:])
+
+        foo = TestJarStruct.Foo(data[1:])
+        self.assertEqual(foo["foo"], 0x45444342)
+        self.assertEqual(foo["bar"], 0xCDAB)
+        self.assertEqual(foo["qux"], 0x01EF)
+        self.assertFalse("length" in foo)
+        self.assertFalse("length2" in foo)
+        self.assertEqual(foo["string"], b"012345")
+        self.assertEqual(foo["string2"], b"67")
+
+    def test_read_jar_struct(self):
+        data = (
+            b"\x00\x04\x03\x02\x01\x42\x43\x44\x45\xab\xcd\xef"
+            + b"\x01\x06\x00\x02\x0001234567890"
+        )
+        self.do_test_read_jar_struct(data)
+
+    def test_read_jar_struct_memoryview(self):
+        data = (
+            b"\x00\x04\x03\x02\x01\x42\x43\x44\x45\xab\xcd\xef"
+            + b"\x01\x06\x00\x02\x0001234567890"
+        )
+        self.do_test_read_jar_struct(memoryview(data))
+
+
+class TestDeflater(unittest.TestCase):
+    def wrap(self, data):
+        return data
+
+    def test_deflater_no_compress(self):
+        deflater = Deflater(False)
+        deflater.write(self.wrap(b"abc"))
+        self.assertFalse(deflater.compressed)
+        self.assertEqual(deflater.uncompressed_size, 3)
+        self.assertEqual(deflater.compressed_size, deflater.uncompressed_size)
+        self.assertEqual(deflater.compressed_data, b"abc")
+        self.assertEqual(deflater.crc32, 0x352441C2)
+
+    def test_deflater_compress_no_gain(self):
+        deflater = Deflater(True)
+        deflater.write(self.wrap(b"abc"))
+        self.assertFalse(deflater.compressed)
+        self.assertEqual(deflater.uncompressed_size, 3)
+        self.assertEqual(deflater.compressed_size, deflater.uncompressed_size)
+        self.assertEqual(deflater.compressed_data, b"abc")
+        self.assertEqual(deflater.crc32, 0x352441C2)
+
+    def test_deflater_compress(self):
+        deflater = Deflater(True)
+        deflater.write(self.wrap(b"aaaaaaaaaaaaanopqrstuvwxyz"))
+        self.assertTrue(deflater.compressed)
+        self.assertEqual(deflater.uncompressed_size, 26)
+        self.assertNotEqual(deflater.compressed_size, deflater.uncompressed_size)
+        self.assertEqual(deflater.crc32, 0xD46B97ED)
+        # The CRC is the same as when not compressed
+        deflater = Deflater(False)
+        self.assertFalse(deflater.compressed)
+        deflater.write(self.wrap(b"aaaaaaaaaaaaanopqrstuvwxyz"))
+        self.assertEqual(deflater.crc32, 0xD46B97ED)
+
+    def test_deflater_empty(self):
+        deflater = Deflater(False)
+        self.assertFalse(deflater.compressed)
+        self.assertEqual(deflater.uncompressed_size, 0)
+        self.assertEqual(deflater.compressed_size, deflater.uncompressed_size)
+        self.assertEqual(deflater.compressed_data, b"")
+        self.assertEqual(deflater.crc32, 0)
+
+
+class TestDeflaterMemoryView(TestDeflater):
+    def wrap(self, data):
+        return memoryview(data)
+
+
+class TestJar(unittest.TestCase):
+    def test_jar(self):
+        s = MockDest()
+        with JarWriter(fileobj=s) as jar:
+            jar.add("foo", b"foo")
+            self.assertRaises(JarWriterError, jar.add, "foo", b"bar")
+            jar.add("bar", b"aaaaaaaaaaaaanopqrstuvwxyz")
+            jar.add("baz/qux", b"aaaaaaaaaaaaanopqrstuvwxyz", False)
+            jar.add("baz\\backslash", b"aaaaaaaaaaaaaaa")
+
+        files = [j for j in JarReader(fileobj=s)]
+
+        self.assertEqual(files[0].filename, "foo")
+        self.assertFalse(files[0].compressed)
+        self.assertEqual(files[0].read(), b"foo")
+
+        self.assertEqual(files[1].filename, "bar")
+        self.assertTrue(files[1].compressed)
+        self.assertEqual(files[1].read(), b"aaaaaaaaaaaaanopqrstuvwxyz")
+
+        self.assertEqual(files[2].filename, "baz/qux")
+        self.assertFalse(files[2].compressed)
+        self.assertEqual(files[2].read(), b"aaaaaaaaaaaaanopqrstuvwxyz")
+
+        if os.sep == "\\":
+            self.assertEqual(
+                files[3].filename,
+                "baz/backslash",
+                "backslashes in filenames on Windows should get normalized",
+            )
+        else:
+            self.assertEqual(
+                files[3].filename,
+                "baz\\backslash",
+                "backslashes in filenames on POSIX platform are untouched",
+            )
+
+        s = MockDest()
+        with JarWriter(fileobj=s, compress=False) as jar:
+            jar.add("bar", b"aaaaaaaaaaaaanopqrstuvwxyz")
+            jar.add("foo", b"foo")
+            jar.add("baz/qux", b"aaaaaaaaaaaaanopqrstuvwxyz", True)
+
+        jar = JarReader(fileobj=s)
+        files = [j for j in jar]
+
+        self.assertEqual(files[0].filename, "bar")
+        self.assertFalse(files[0].compressed)
+        self.assertEqual(files[0].read(), b"aaaaaaaaaaaaanopqrstuvwxyz")
+
+        self.assertEqual(files[1].filename, "foo")
+        self.assertFalse(files[1].compressed)
+        self.assertEqual(files[1].read(), b"foo")
+
+        self.assertEqual(files[2].filename, "baz/qux")
+        self.assertTrue(files[2].compressed)
+        self.assertEqual(files[2].read(), b"aaaaaaaaaaaaanopqrstuvwxyz")
+
+        self.assertTrue("bar" in jar)
+        self.assertTrue("foo" in jar)
+        self.assertFalse("baz" in jar)
+        self.assertTrue("baz/qux" in jar)
+        self.assertTrue(jar["bar"], files[1])
+        self.assertTrue(jar["foo"], files[0])
+        self.assertTrue(jar["baz/qux"], files[2])
+
+        s.seek(0)
+        jar = JarReader(fileobj=s)
+        self.assertTrue("bar" in jar)
+        self.assertTrue("foo" in jar)
+        self.assertFalse("baz" in jar)
+        self.assertTrue("baz/qux" in jar)
+
+        files[0].seek(0)
+        self.assertEqual(jar["bar"].filename, files[0].filename)
+        self.assertEqual(jar["bar"].compressed, files[0].compressed)
+        self.assertEqual(jar["bar"].read(), files[0].read())
+
+        files[1].seek(0)
+        self.assertEqual(jar["foo"].filename, files[1].filename)
+        self.assertEqual(jar["foo"].compressed, files[1].compressed)
+        self.assertEqual(jar["foo"].read(), files[1].read())
+
+        files[2].seek(0)
+        self.assertEqual(jar["baz/qux"].filename, files[2].filename)
+        self.assertEqual(jar["baz/qux"].compressed, files[2].compressed)
+        self.assertEqual(jar["baz/qux"].read(), files[2].read())
+
+    def test_rejar(self):
+        s = MockDest()
+        with JarWriter(fileobj=s) as jar:
+            jar.add("foo", b"foo")
+            jar.add("bar", b"aaaaaaaaaaaaanopqrstuvwxyz")
+            jar.add("baz/qux", b"aaaaaaaaaaaaanopqrstuvwxyz", False)
+
+        new = MockDest()
+        with JarWriter(fileobj=new) as jar:
+            for j in JarReader(fileobj=s):
+                jar.add(j.filename, j)
+
+        jar = JarReader(fileobj=new)
+        files = [j for j in jar]
+
+        self.assertEqual(files[0].filename, "foo")
+        self.assertFalse(files[0].compressed)
+        self.assertEqual(files[0].read(), b"foo")
+
+        self.assertEqual(files[1].filename, "bar")
+        self.assertTrue(files[1].compressed)
+        self.assertEqual(files[1].read(), b"aaaaaaaaaaaaanopqrstuvwxyz")
+
+        self.assertEqual(files[2].filename, "baz/qux")
+        self.assertTrue(files[2].compressed)
+        self.assertEqual(files[2].read(), b"aaaaaaaaaaaaanopqrstuvwxyz")
+
+    def test_add_from_finder(self):
+        s = MockDest()
+        with JarWriter(fileobj=s) as jar:
+            finder = FileFinder(test_data_path)
+            for p, f in finder.find("test_data"):
+                jar.add("test_data", f)
+
+        jar = JarReader(fileobj=s)
+        files = [j for j in jar]
+
+        self.assertEqual(files[0].filename, "test_data")
+        self.assertFalse(files[0].compressed)
+        self.assertEqual(files[0].read(), b"test_data")
+
+
+class TestPreload(unittest.TestCase):
+    def test_preload(self):
+        s = MockDest()
+        with JarWriter(fileobj=s) as jar:
+            jar.add("foo", b"foo")
+            jar.add("bar", b"abcdefghijklmnopqrstuvwxyz")
+            jar.add("baz/qux", b"aaaaaaaaaaaaanopqrstuvwxyz")
+
+        jar = JarReader(fileobj=s)
+        self.assertEqual(jar.last_preloaded, None)
+
+        with JarWriter(fileobj=s) as jar:
+            jar.add("foo", b"foo")
+            jar.add("bar", b"abcdefghijklmnopqrstuvwxyz")
+            jar.add("baz/qux", b"aaaaaaaaaaaaanopqrstuvwxyz")
+            jar.preload(["baz/qux", "bar"])
+
+        jar = JarReader(fileobj=s)
+        self.assertEqual(jar.last_preloaded, "bar")
+        files = [j for j in jar]
+
+        self.assertEqual(files[0].filename, "baz/qux")
+        self.assertEqual(files[1].filename, "bar")
+        self.assertEqual(files[2].filename, "foo")
+
+
+class TestJarLog(unittest.TestCase):
+    def test_jarlog(self):
+        s = six.moves.cStringIO(
+            "\n".join(
+                [
+                    "bar/baz.jar first",
+                    "bar/baz.jar second",
+                    "bar/baz.jar third",
+                    "bar/baz.jar second",
+                    "bar/baz.jar second",
+                    "omni.ja stuff",
+                    "bar/baz.jar first",
+                    "omni.ja other/stuff",
+                    "omni.ja stuff",
+                    "bar/baz.jar third",
+                ]
+            )
+        )
+        log = JarLog(fileobj=s)
+        self.assertEqual(
+            set(log.keys()),
+            set(
+                [
+                    "bar/baz.jar",
+                    "omni.ja",
+                ]
+            ),
+        )
+        self.assertEqual(
+            log["bar/baz.jar"],
+            [
+                "first",
+                "second",
+                "third",
+            ],
+        )
+        self.assertEqual(
+            log["omni.ja"],
+            [
+                "stuff",
+                "other/stuff",
+            ],
+        )
+
+
+if __name__ == "__main__":
+    mozunit.main()
diff --git a/python/mozbuild/mozpack/test/test_packager.py b/python/mozbuild/mozpack/test/test_packager.py
new file mode 100644
index 0000000000..266902ebb2
--- /dev/null
+++ b/python/mozbuild/mozpack/test/test_packager.py
@@ -0,0 +1,630 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+import os
+import unittest
+
+import mozunit
+from buildconfig import topobjdir
+from mozunit import MockedOpen
+
+import mozpack.path as mozpath
+from mozbuild.preprocessor import Preprocessor
+from mozpack.chrome.manifest import (
+    ManifestBinaryComponent,
+    ManifestContent,
+    ManifestResource,
+)
+from mozpack.errors import ErrorMessage, errors
+from mozpack.files import GeneratedFile
+from mozpack.packager import (
+    CallDeque,
+    Component,
+    SimpleManifestSink,
+    SimplePackager,
+    preprocess_manifest,
+)
+
+MANIFEST = """
+bar/*
+[foo]
+foo/*
+-foo/bar
+chrome.manifest
+[zot destdir="destdir"]
+foo/zot
+; comment
+#ifdef baz
+[baz]
+baz@SUFFIX@
+#endif
+"""
+
+
+class TestPreprocessManifest(unittest.TestCase):
+    MANIFEST_PATH = mozpath.join("$OBJDIR", "manifest")
+
+    EXPECTED_LOG = [
+        ((MANIFEST_PATH, 2), "add", "", "bar/*"),
+        ((MANIFEST_PATH, 4), "add", "foo", "foo/*"),
+        ((MANIFEST_PATH, 5), "remove", "foo", "foo/bar"),
+        ((MANIFEST_PATH, 6), "add", "foo", "chrome.manifest"),
+        ((MANIFEST_PATH, 8), "add", 'zot destdir="destdir"', "foo/zot"),
+    ]
+
+    def setUp(self):
+        class MockSink(object):
+            def __init__(self):
+                self.log = []
+
+            def add(self, component, path):
+                self._log(errors.get_context(), "add", repr(component), path)
+
+            def remove(self, component, path):
+                self._log(errors.get_context(), "remove", repr(component), path)
+
+            def _log(self, *args):
+                self.log.append(args)
+
+        self.sink = MockSink()
+        self.cwd = os.getcwd()
+        os.chdir(topobjdir)
+
+    def tearDown(self):
+        os.chdir(self.cwd)
+
+    def test_preprocess_manifest(self):
+        with MockedOpen({"manifest": MANIFEST}):
+            preprocess_manifest(self.sink, "manifest")
+        self.assertEqual(self.sink.log, self.EXPECTED_LOG)
+
+    def test_preprocess_manifest_missing_define(self):
+        with MockedOpen({"manifest": MANIFEST}):
+            self.assertRaises(
+                Preprocessor.Error,
+                preprocess_manifest,
+                self.sink,
+                "manifest",
+                {"baz": 1},
+            )
+
+    def test_preprocess_manifest_defines(self):
+        with MockedOpen({"manifest": MANIFEST}):
+            preprocess_manifest(self.sink, "manifest", {"baz": 1, "SUFFIX": ".exe"})
+        self.assertEqual(
+            self.sink.log,
+            self.EXPECTED_LOG + [((self.MANIFEST_PATH, 12), "add", "baz", "baz.exe")],
+        )
+
+
+class MockFinder(object):
+    def __init__(self, files):
+        self.files = files
+        self.log = []
+
+    def find(self, path):
+        self.log.append(path)
+        for f in sorted(self.files):
+            if mozpath.match(f, path):
+                yield f, self.files[f]
+
+    def __iter__(self):
+        return self.find("")
+
+
+class MockFormatter(object):
+    def __init__(self):
+        self.log = []
+
+    def add_base(self, *args):
+        self._log(errors.get_context(), "add_base", *args)
+
+    def add_manifest(self, *args):
+        self._log(errors.get_context(), "add_manifest", *args)
+
+    def add_interfaces(self, *args):
+        self._log(errors.get_context(), "add_interfaces", *args)
+
+    def add(self, *args):
+        self._log(errors.get_context(), "add", *args)
+
+    def _log(self, *args):
+        self.log.append(args)
+
+
+class TestSimplePackager(unittest.TestCase):
+    def test_simple_packager(self):
+        class GeneratedFileWithPath(GeneratedFile):
+            def __init__(self, path, content):
+                GeneratedFile.__init__(self, content)
+                self.path = path
+
+        formatter = MockFormatter()
+        packager = SimplePackager(formatter)
+        curdir = os.path.abspath(os.curdir)
+        file = GeneratedFileWithPath(
+            os.path.join(curdir, "foo", "bar.manifest"),
+            b"resource bar bar/\ncontent bar bar/",
+        )
+        with errors.context("manifest", 1):
+            packager.add("foo/bar.manifest", file)
+
+        file = GeneratedFileWithPath(
+            os.path.join(curdir, "foo", "baz.manifest"), b"resource baz baz/"
+        )
+        with errors.context("manifest", 2):
+            packager.add("bar/baz.manifest", file)
+
+        with errors.context("manifest", 3):
+            packager.add(
+                "qux/qux.manifest",
+                GeneratedFile(
+                    b"".join(
+                        [
+                            b"resource qux qux/\n",
+                            b"binary-component qux.so\n",
+                        ]
+                    )
+                ),
+            )
+        bar_xpt = GeneratedFile(b"bar.xpt")
+        qux_xpt = GeneratedFile(b"qux.xpt")
+        foo_html = GeneratedFile(b"foo_html")
+        bar_html = GeneratedFile(b"bar_html")
+        with errors.context("manifest", 4):
+            packager.add("foo/bar.xpt", bar_xpt)
+        with errors.context("manifest", 5):
+            packager.add("foo/bar/foo.html", foo_html)
+            packager.add("foo/bar/bar.html", bar_html)
+
+        file = GeneratedFileWithPath(
+            os.path.join(curdir, "foo.manifest"),
+            b"".join(
+                [
+                    b"manifest foo/bar.manifest\n",
+                    b"manifest bar/baz.manifest\n",
+                ]
+            ),
+        )
+        with errors.context("manifest", 6):
+            packager.add("foo.manifest", file)
+        with errors.context("manifest", 7):
+            packager.add("foo/qux.xpt", qux_xpt)
+
+        file = GeneratedFileWithPath(
+            os.path.join(curdir, "addon", "chrome.manifest"), b"resource hoge hoge/"
+        )
+        with errors.context("manifest", 8):
+            packager.add("addon/chrome.manifest", file)
+
+        install_rdf = GeneratedFile(b"<RDF></RDF>")
+        with errors.context("manifest", 9):
+            packager.add("addon/install.rdf", install_rdf)
+
+        with errors.context("manifest", 10):
+            packager.add("addon2/install.rdf", install_rdf)
+            packager.add(
+                "addon2/chrome.manifest", GeneratedFile(b"binary-component addon2.so")
+            )
+
+        with errors.context("manifest", 11):
+            packager.add("addon3/install.rdf", install_rdf)
+            packager.add(
+                "addon3/chrome.manifest",
+                GeneratedFile(b"manifest components/components.manifest"),
+            )
+            packager.add(
+                "addon3/components/components.manifest",
+                GeneratedFile(b"binary-component addon3.so"),
+            )
+
+        with errors.context("manifest", 12):
+            install_rdf_addon4 = GeneratedFile(
+                b"<RDF>\n<...>\n<em:unpack>true</em:unpack>\n<...>\n</RDF>"
+            )
+            packager.add("addon4/install.rdf", install_rdf_addon4)
+
+        with errors.context("manifest", 13):
+            install_rdf_addon5 = GeneratedFile(
+                b"<RDF>\n<...>\n<em:unpack>false</em:unpack>\n<...>\n</RDF>"
+            )
+            packager.add("addon5/install.rdf", install_rdf_addon5)
+
+        with errors.context("manifest", 14):
+            install_rdf_addon6 = GeneratedFile(
+                b"<RDF>\n<... em:unpack=true>\n<...>\n</RDF>"
+            )
+            packager.add("addon6/install.rdf", install_rdf_addon6)
+
+        with errors.context("manifest", 15):
+            install_rdf_addon7 = GeneratedFile(
+                b"<RDF>\n<... em:unpack=false>\n<...>\n</RDF>"
+            )
+            packager.add("addon7/install.rdf", install_rdf_addon7)
+
+        with errors.context("manifest", 16):
+            install_rdf_addon8 = GeneratedFile(
+                b'<RDF>\n<... em:unpack="true">\n<...>\n</RDF>'
+            )
+            packager.add("addon8/install.rdf", install_rdf_addon8)
+
+        with errors.context("manifest", 17):
+            install_rdf_addon9 = GeneratedFile(
+                b'<RDF>\n<... em:unpack="false">\n<...>\n</RDF>'
+            )
+            packager.add("addon9/install.rdf", install_rdf_addon9)
+
+        with errors.context("manifest", 18):
+            install_rdf_addon10 = GeneratedFile(
+                b"<RDF>\n<... em:unpack='true'>\n<...>\n</RDF>"
+            )
+            packager.add("addon10/install.rdf", install_rdf_addon10)
+
+        with errors.context("manifest", 19):
+            install_rdf_addon11 = GeneratedFile(
+                b"<RDF>\n<... em:unpack='false'>\n<...>\n</RDF>"
+            )
+            packager.add("addon11/install.rdf", install_rdf_addon11)
+
+        we_manifest = GeneratedFile(
+            b'{"manifest_version": 2, "name": "Test WebExtension", "version": "1.0"}'
+        )
+        # hybrid and hybrid2 are both bootstrapped extensions with
+        # embedded webextensions, they differ in the order in which
+        # the manifests are added to the packager.
+        with errors.context("manifest", 20):
+            packager.add("hybrid/install.rdf", install_rdf)
+
+        with errors.context("manifest", 21):
+            packager.add("hybrid/webextension/manifest.json", we_manifest)
+
+        with errors.context("manifest", 22):
+            packager.add("hybrid2/webextension/manifest.json", we_manifest)
+
+        with errors.context("manifest", 23):
+            packager.add("hybrid2/install.rdf", install_rdf)
+
+        with errors.context("manifest", 24):
+            packager.add("webextension/manifest.json", we_manifest)
+
+        non_we_manifest = GeneratedFile(b'{"not a webextension": true}')
+        with errors.context("manifest", 25):
+            packager.add("nonwebextension/manifest.json", non_we_manifest)
+
+        self.assertEqual(formatter.log, [])
+
+        with errors.context("dummy", 1):
+            packager.close()
+        self.maxDiff = None
+        # The formatter is expected to reorder the manifest entries so that
+        # chrome entries appear before the others.
+        self.assertEqual(
+            formatter.log,
+            [
+                (("dummy", 1), "add_base", "", False),
+                (("dummy", 1), "add_base", "addon", True),
+                (("dummy", 1), "add_base", "addon10", "unpacked"),
+                (("dummy", 1), "add_base", "addon11", True),
+                (("dummy", 1), "add_base", "addon2", "unpacked"),
+                (("dummy", 1), "add_base", "addon3", "unpacked"),
+                (("dummy", 1), "add_base", "addon4", "unpacked"),
+                (("dummy", 1), "add_base", "addon5", True),
+                (("dummy", 1), "add_base", "addon6", "unpacked"),
+                (("dummy", 1), "add_base", "addon7", True),
+                (("dummy", 1), "add_base", "addon8", "unpacked"),
+                (("dummy", 1), "add_base", "addon9", True),
+                (("dummy", 1), "add_base", "hybrid", True),
+                (("dummy", 1), "add_base", "hybrid2", True),
+                (("dummy", 1), "add_base", "qux", False),
+                (("dummy", 1), "add_base", "webextension", True),
+                (
+                    (os.path.join(curdir, "foo", "bar.manifest"), 2),
+                    "add_manifest",
+                    ManifestContent("foo", "bar", "bar/"),
+                ),
+                (
+                    (os.path.join(curdir, "foo", "bar.manifest"), 1),
+                    "add_manifest",
+                    ManifestResource("foo", "bar", "bar/"),
+                ),
+                (
+                    ("bar/baz.manifest", 1),
+                    "add_manifest",
+                    ManifestResource("bar", "baz", "baz/"),
+                ),
+                (
+                    ("qux/qux.manifest", 1),
+                    "add_manifest",
+                    ManifestResource("qux", "qux", "qux/"),
+                ),
+                (
+                    ("qux/qux.manifest", 2),
+                    "add_manifest",
+                    ManifestBinaryComponent("qux", "qux.so"),
+                ),
+                (("manifest", 4), "add_interfaces", "foo/bar.xpt", bar_xpt),
+                (("manifest", 7), "add_interfaces", "foo/qux.xpt", qux_xpt),
+                (
+                    (os.path.join(curdir, "addon", "chrome.manifest"), 1),
+                    "add_manifest",
+                    ManifestResource("addon", "hoge", "hoge/"),
+                ),
+                (
+                    ("addon2/chrome.manifest", 1),
+                    "add_manifest",
+                    ManifestBinaryComponent("addon2", "addon2.so"),
+                ),
+                (
+                    ("addon3/components/components.manifest", 1),
+                    "add_manifest",
+                    ManifestBinaryComponent("addon3/components", "addon3.so"),
+                ),
+                (("manifest", 5), "add", "foo/bar/foo.html", foo_html),
+                (("manifest", 5), "add", "foo/bar/bar.html", bar_html),
+                (("manifest", 9), "add", "addon/install.rdf", install_rdf),
+                (("manifest", 10), "add", "addon2/install.rdf", install_rdf),
+                (("manifest", 11), "add", "addon3/install.rdf", install_rdf),
+                (("manifest", 12), "add", "addon4/install.rdf", install_rdf_addon4),
+                (("manifest", 13), "add", "addon5/install.rdf", install_rdf_addon5),
+                (("manifest", 14), "add", "addon6/install.rdf", install_rdf_addon6),
+                (("manifest", 15), "add", "addon7/install.rdf", install_rdf_addon7),
+                (("manifest", 16), "add", "addon8/install.rdf", install_rdf_addon8),
+                (("manifest", 17), "add", "addon9/install.rdf", install_rdf_addon9),
+                (("manifest", 18), "add", "addon10/install.rdf", install_rdf_addon10),
+                (("manifest", 19), "add", "addon11/install.rdf", install_rdf_addon11),
+                (("manifest", 20), "add", "hybrid/install.rdf", install_rdf),
+                (
+                    ("manifest", 21),
+                    "add",
+                    "hybrid/webextension/manifest.json",
+                    we_manifest,
+                ),
+                (
+                    ("manifest", 22),
+                    "add",
+                    "hybrid2/webextension/manifest.json",
+                    we_manifest,
+                ),
+                (("manifest", 23), "add", "hybrid2/install.rdf", install_rdf),
+                (("manifest", 24), "add", "webextension/manifest.json", we_manifest),
+                (
+                    ("manifest", 25),
+                    "add",
+                    "nonwebextension/manifest.json",
+                    non_we_manifest,
+                ),
+            ],
+        )
+
+        self.assertEqual(
+            packager.get_bases(),
+            set(
+                [
+                    "",
+                    "addon",
+                    "addon2",
+                    "addon3",
+                    "addon4",
+                    "addon5",
+                    "addon6",
+                    "addon7",
+                    "addon8",
+                    "addon9",
+                    "addon10",
+                    "addon11",
+                    "qux",
+                    "hybrid",
+                    "hybrid2",
+                    "webextension",
+                ]
+            ),
+        )
+        self.assertEqual(packager.get_bases(addons=False), set(["", "qux"]))
+
+    def test_simple_packager_manifest_consistency(self):
+        formatter = MockFormatter()
+        # bar/ is detected as an addon because of install.rdf, but top-level
+        # includes a manifest inside bar/.
+        packager = SimplePackager(formatter)
+        packager.add(
+            "base.manifest",
+            GeneratedFile(
+                b"manifest foo/bar.manifest\n" b"manifest bar/baz.manifest\n"
+            ),
+        )
+        packager.add("foo/bar.manifest", GeneratedFile(b"resource bar bar"))
+        packager.add("bar/baz.manifest", GeneratedFile(b"resource baz baz"))
+        packager.add("bar/install.rdf", GeneratedFile(b""))
+
+        with self.assertRaises(ErrorMessage) as e:
+            packager.close()
+
+        self.assertEqual(
+            str(e.exception),
+            'error: "bar/baz.manifest" is included from "base.manifest", '
+            'which is outside "bar"',
+        )
+
+        # bar/ is detected as a separate base because of chrome.manifest that
+        # is included nowhere, but top-level includes another manifest inside
+        # bar/.
+        packager = SimplePackager(formatter)
+        packager.add(
+            "base.manifest",
+            GeneratedFile(
+                b"manifest foo/bar.manifest\n" b"manifest bar/baz.manifest\n"
+            ),
+        )
+        packager.add("foo/bar.manifest", GeneratedFile(b"resource bar bar"))
+        packager.add("bar/baz.manifest", GeneratedFile(b"resource baz baz"))
+        packager.add("bar/chrome.manifest", GeneratedFile(b"resource baz baz"))
+
+        with self.assertRaises(ErrorMessage) as e:
+            packager.close()
+
+        self.assertEqual(
+            str(e.exception),
+            'error: "bar/baz.manifest" is included from "base.manifest", '
+            'which is outside "bar"',
+        )
+
+        # bar/ is detected as a separate base because of chrome.manifest that
+        # is included nowhere, but chrome.manifest includes baz.manifest from
+        # the same directory. This shouldn't error out.
+        packager = SimplePackager(formatter)
+        packager.add("base.manifest", GeneratedFile(b"manifest foo/bar.manifest\n"))
+        packager.add("foo/bar.manifest", GeneratedFile(b"resource bar bar"))
+        packager.add("bar/baz.manifest", GeneratedFile(b"resource baz baz"))
+        packager.add("bar/chrome.manifest", GeneratedFile(b"manifest baz.manifest"))
+        packager.close()
+
+
+class TestSimpleManifestSink(unittest.TestCase):
+    def test_simple_manifest_parser(self):
+        formatter = MockFormatter()
+        foobar = GeneratedFile(b"foobar")
+        foobaz = GeneratedFile(b"foobaz")
+        fooqux = GeneratedFile(b"fooqux")
+        foozot = GeneratedFile(b"foozot")
+        finder = MockFinder(
+            {
+                "bin/foo/bar": foobar,
+                "bin/foo/baz": foobaz,
+                "bin/foo/qux": fooqux,
+                "bin/foo/zot": foozot,
+                "bin/foo/chrome.manifest": GeneratedFile(b"resource foo foo/"),
+                "bin/chrome.manifest": GeneratedFile(b"manifest foo/chrome.manifest"),
+            }
+        )
+        parser = SimpleManifestSink(finder, formatter)
+        component0 = Component("component0")
+        component1 = Component("component1")
+        component2 = Component("component2", destdir="destdir")
+        parser.add(component0, "bin/foo/b*")
+        parser.add(component1, "bin/foo/qux")
+        parser.add(component1, "bin/foo/chrome.manifest")
+        parser.add(component2, "bin/foo/zot")
+        self.assertRaises(ErrorMessage, parser.add, "component1", "bin/bar")
+
+        self.assertEqual(formatter.log, [])
+        parser.close()
+        self.assertEqual(
+            formatter.log,
+            [
+                (None, "add_base", "", False),
+                (
+                    ("foo/chrome.manifest", 1),
+                    "add_manifest",
+                    ManifestResource("foo", "foo", "foo/"),
+                ),
+                (None, "add", "foo/bar", foobar),
+                (None, "add", "foo/baz", foobaz),
+                (None, "add", "foo/qux", fooqux),
+                (None, "add", "destdir/foo/zot", foozot),
+            ],
+        )
+
+        self.assertEqual(
+            finder.log,
+            [
+                "bin/foo/b*",
+                "bin/foo/qux",
+                "bin/foo/chrome.manifest",
+                "bin/foo/zot",
+                "bin/bar",
+                "bin/chrome.manifest",
+            ],
+        )
+
+
+class TestCallDeque(unittest.TestCase):
+    def test_call_deque(self):
+        class Logger(object):
+            def __init__(self):
+                self._log = []
+
+            def log(self, str):
+                self._log.append(str)
+
+            @staticmethod
+            def staticlog(logger, str):
+                logger.log(str)
+
+        def do_log(logger, str):
+            logger.log(str)
+
+        logger = Logger()
+        d = CallDeque()
+        d.append(logger.log, "foo")
+        d.append(logger.log, "bar")
+        d.append(logger.staticlog, logger, "baz")
+        d.append(do_log, logger, "qux")
+        self.assertEqual(logger._log, [])
+        d.execute()
+        self.assertEqual(logger._log, ["foo", "bar", "baz", "qux"])
+
+
+class TestComponent(unittest.TestCase):
+    def do_split(self, string, name, options):
+        n, o = Component._split_component_and_options(string)
+        self.assertEqual(name, n)
+        self.assertEqual(options, o)
+
+    def test_component_split_component_and_options(self):
+        self.do_split("component", "component", {})
+        self.do_split("trailingspace ", "trailingspace", {})
+        self.do_split(" leadingspace", "leadingspace", {})
+        self.do_split(" trim ", "trim", {})
+        self.do_split(' trim key="value"', "trim", {"key": "value"})
+        self.do_split(' trim empty=""', "trim", {"empty": ""})
+        self.do_split(' trim space=" "', "trim", {"space": " "})
+        self.do_split(
+            'component key="value"  key2="second" ',
+            "component",
+            {"key": "value", "key2": "second"},
+        )
+        self.do_split(
+            'trim key="  value with spaces   "  key2="spaces again"',
+            "trim",
+            {"key": "  value with spaces   ", "key2": "spaces again"},
+        )
+
+    def do_split_error(self, string):
+        self.assertRaises(ValueError, Component._split_component_and_options, string)
+
+    def test_component_split_component_and_options_errors(self):
+        self.do_split_error('"component')
+        self.do_split_error('comp"onent')
+        self.do_split_error('component"')
+        self.do_split_error('"component"')
+        self.do_split_error("=component")
+        self.do_split_error("comp=onent")
+        self.do_split_error("component=")
+        self.do_split_error('key="val"')
+        self.do_split_error("component key=")
+        self.do_split_error('component key="val')
+        self.do_split_error('component key=val"')
+        self.do_split_error('component key="val" x')
+        self.do_split_error('component x key="val"')
+        self.do_split_error('component key1="val" x key2="val"')
+
+    def do_from_string(self, string, name, destdir=""):
+        component = Component.from_string(string)
+        self.assertEqual(name, component.name)
+        self.assertEqual(destdir, component.destdir)
+
+    def test_component_from_string(self):
+        self.do_from_string("component", "component")
+        self.do_from_string("component-with-hyphen", "component-with-hyphen")
+        self.do_from_string('component destdir="foo/bar"', "component", "foo/bar")
+        self.do_from_string('component destdir="bar spc"', "component", "bar spc")
+        self.assertRaises(ErrorMessage, Component.from_string, "")
+        self.assertRaises(ErrorMessage, Component.from_string, "component novalue=")
+        self.assertRaises(
+            ErrorMessage, Component.from_string, "component badoption=badvalue"
+        )
+
+
+if __name__ == "__main__":
+    mozunit.main()
diff --git a/python/mozbuild/mozpack/test/test_packager_formats.py b/python/mozbuild/mozpack/test/test_packager_formats.py
new file mode 100644
index 0000000000..b09971a102
--- /dev/null
+++ b/python/mozbuild/mozpack/test/test_packager_formats.py
@@ -0,0 +1,537 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+import unittest
+from itertools import chain
+
+import mozunit
+import six
+
+import mozpack.path as mozpath
+from mozpack.chrome.manifest import (
+    ManifestBinaryComponent,
+    ManifestComponent,
+    ManifestContent,
+    ManifestLocale,
+    ManifestResource,
+    ManifestSkin,
+)
+from mozpack.copier import FileRegistry
+from mozpack.errors import ErrorMessage
+from mozpack.files import GeneratedFile, ManifestFile
+from mozpack.packager.formats import FlatFormatter, JarFormatter, OmniJarFormatter
+from mozpack.test.test_files import bar_xpt, foo2_xpt, foo_xpt
+from test_errors import TestErrors
+
+CONTENTS = {
+    "bases": {
+        # base_path: is_addon?
+        "": False,
+        "app": False,
+        "addon0": "unpacked",
+        "addon1": True,
+        "app/chrome/addons/addon2": True,
+    },
+    "manifests": [
+        ManifestContent("chrome/f", "oo", "oo/"),
+        ManifestContent("chrome/f", "bar", "oo/bar/"),
+        ManifestResource("chrome/f", "foo", "resource://bar/"),
+        ManifestBinaryComponent("components", "foo.so"),
+        ManifestContent("app/chrome", "content", "foo/"),
+        ManifestComponent("app/components", "{foo-id}", "foo.js"),
+        ManifestContent("addon0/chrome", "addon0", "foo/bar/"),
+        ManifestContent("addon1/chrome", "addon1", "foo/bar/"),
+        ManifestContent("app/chrome/addons/addon2/chrome", "addon2", "foo/bar/"),
+    ],
+    "files": {
+        "chrome/f/oo/bar/baz": GeneratedFile(b"foobarbaz"),
+        "chrome/f/oo/baz": GeneratedFile(b"foobaz"),
+        "chrome/f/oo/qux": GeneratedFile(b"fooqux"),
+        "components/foo.so": GeneratedFile(b"foo.so"),
+        "components/foo.xpt": foo_xpt,
+        "components/bar.xpt": bar_xpt,
+        "foo": GeneratedFile(b"foo"),
+        "app/chrome/foo/foo": GeneratedFile(b"appfoo"),
+        "app/components/foo.js": GeneratedFile(b"foo.js"),
+        "addon0/chrome/foo/bar/baz": GeneratedFile(b"foobarbaz"),
+        "addon0/components/foo.xpt": foo2_xpt,
+        "addon0/components/bar.xpt": bar_xpt,
+        "addon1/chrome/foo/bar/baz": GeneratedFile(b"foobarbaz"),
+        "addon1/components/foo.xpt": foo2_xpt,
+        "addon1/components/bar.xpt": bar_xpt,
+        "app/chrome/addons/addon2/chrome/foo/bar/baz": GeneratedFile(b"foobarbaz"),
+        "app/chrome/addons/addon2/components/foo.xpt": foo2_xpt,
+        "app/chrome/addons/addon2/components/bar.xpt": bar_xpt,
+    },
+}
+
+FILES = CONTENTS["files"]
+
+RESULT_FLAT = {
+    "chrome.manifest": [
+        "manifest chrome/chrome.manifest",
+        "manifest components/components.manifest",
+    ],
+    "chrome/chrome.manifest": [
+        "manifest f/f.manifest",
+    ],
+    "chrome/f/f.manifest": [
+        "content oo oo/",
+        "content bar oo/bar/",
+        "resource foo resource://bar/",
+    ],
+    "chrome/f/oo/bar/baz": FILES["chrome/f/oo/bar/baz"],
+    "chrome/f/oo/baz": FILES["chrome/f/oo/baz"],
+    "chrome/f/oo/qux": FILES["chrome/f/oo/qux"],
+    "components/components.manifest": [
+        "binary-component foo.so",
+        "interfaces bar.xpt",
+        "interfaces foo.xpt",
+    ],
+    "components/foo.so": FILES["components/foo.so"],
+    "components/foo.xpt": foo_xpt,
+    "components/bar.xpt": bar_xpt,
+    "foo": FILES["foo"],
+    "app/chrome.manifest": [
+        "manifest chrome/chrome.manifest",
+        "manifest components/components.manifest",
+    ],
+    "app/chrome/chrome.manifest": [
+        "content content foo/",
+    ],
+    "app/chrome/foo/foo": FILES["app/chrome/foo/foo"],
+    "app/components/components.manifest": [
+        "component {foo-id} foo.js",
+    ],
+    "app/components/foo.js": FILES["app/components/foo.js"],
+}
+
+for addon in ("addon0", "addon1", "app/chrome/addons/addon2"):
+    RESULT_FLAT.update(
+        {
+            mozpath.join(addon, p): f
+            for p, f in six.iteritems(
+                {
+                    "chrome.manifest": [
+                        "manifest chrome/chrome.manifest",
+                        "manifest components/components.manifest",
+                    ],
+                    "chrome/chrome.manifest": [
+                        "content %s foo/bar/" % mozpath.basename(addon),
+                    ],
+                    "chrome/foo/bar/baz": FILES[
+                        mozpath.join(addon, "chrome/foo/bar/baz")
+                    ],
+                    "components/components.manifest": [
+                        "interfaces bar.xpt",
+                        "interfaces foo.xpt",
+                    ],
+                    "components/bar.xpt": bar_xpt,
+                    "components/foo.xpt": foo2_xpt,
+                }
+            )
+        }
+    )
+
+RESULT_JAR = {
+    p: RESULT_FLAT[p]
+    for p in (
+        "chrome.manifest",
+        "chrome/chrome.manifest",
+        "components/components.manifest",
+        "components/foo.so",
+        "components/foo.xpt",
+        "components/bar.xpt",
+        "foo",
+        "app/chrome.manifest",
+        "app/components/components.manifest",
+        "app/components/foo.js",
+        "addon0/chrome.manifest",
+        "addon0/components/components.manifest",
+        "addon0/components/foo.xpt",
+        "addon0/components/bar.xpt",
+    )
+}
+
+RESULT_JAR.update(
+    {
+        "chrome/f/f.manifest": [
+            "content oo jar:oo.jar!/",
+            "content bar jar:oo.jar!/bar/",
+            "resource foo resource://bar/",
+        ],
+        "chrome/f/oo.jar": {
+            "bar/baz": FILES["chrome/f/oo/bar/baz"],
+            "baz": FILES["chrome/f/oo/baz"],
+            "qux": FILES["chrome/f/oo/qux"],
+        },
+        "app/chrome/chrome.manifest": [
+            "content content jar:foo.jar!/",
+        ],
+        "app/chrome/foo.jar": {
+            "foo": FILES["app/chrome/foo/foo"],
+        },
+        "addon0/chrome/chrome.manifest": [
+            "content addon0 jar:foo.jar!/bar/",
+        ],
+        "addon0/chrome/foo.jar": {
+            "bar/baz": FILES["addon0/chrome/foo/bar/baz"],
+        },
+        "addon1.xpi": {
+            mozpath.relpath(p, "addon1"): f
+            for p, f in six.iteritems(RESULT_FLAT)
+            if p.startswith("addon1/")
+        },
+        "app/chrome/addons/addon2.xpi": {
+            mozpath.relpath(p, "app/chrome/addons/addon2"): f
+            for p, f in six.iteritems(RESULT_FLAT)
+            if p.startswith("app/chrome/addons/addon2/")
+        },
+    }
+)
+
+RESULT_OMNIJAR = {
+    p: RESULT_FLAT[p]
+    for p in (
+        "components/foo.so",
+        "foo",
+    )
+}
+
+RESULT_OMNIJAR.update({p: RESULT_JAR[p] for p in RESULT_JAR if p.startswith("addon")})
+
+RESULT_OMNIJAR.update(
+    {
+        "omni.foo": {
+            "components/components.manifest": [
+                "interfaces bar.xpt",
+                "interfaces foo.xpt",
+            ],
+        },
+        "chrome.manifest": [
+            "manifest components/components.manifest",
+        ],
+        "components/components.manifest": [
+            "binary-component foo.so",
+        ],
+        "app/omni.foo": {
+            p: RESULT_FLAT["app/" + p]
+            for p in chain(
+                (
+                    "chrome.manifest",
+                    "chrome/chrome.manifest",
+                    "chrome/foo/foo",
+                    "components/components.manifest",
+                    "components/foo.js",
+                ),
+                (
+                    mozpath.relpath(p, "app")
+                    for p in six.iterkeys(RESULT_FLAT)
+                    if p.startswith("app/chrome/addons/addon2/")
+                ),
+            )
+        },
+    }
+)
+
+RESULT_OMNIJAR["omni.foo"].update(
+    {
+        p: RESULT_FLAT[p]
+        for p in (
+            "chrome.manifest",
+            "chrome/chrome.manifest",
+            "chrome/f/f.manifest",
+            "chrome/f/oo/bar/baz",
+            "chrome/f/oo/baz",
+            "chrome/f/oo/qux",
+            "components/foo.xpt",
+            "components/bar.xpt",
+        )
+    }
+)
+
+RESULT_OMNIJAR_WITH_SUBPATH = {
+    k.replace("omni.foo", "bar/omni.foo"): v for k, v in RESULT_OMNIJAR.items()
+}
+
+CONTENTS_WITH_BASE = {
+    "bases": {
+        mozpath.join("base/root", b) if b else "base/root": a
+        for b, a in six.iteritems(CONTENTS["bases"])
+    },
+    "manifests": [
+        m.move(mozpath.join("base/root", m.base)) for m in CONTENTS["manifests"]
+    ],
+    "files": {
+        mozpath.join("base/root", p): f for p, f in six.iteritems(CONTENTS["files"])
+    },
+}
+
+EXTRA_CONTENTS = {
+    "extra/file": GeneratedFile(b"extra file"),
+}
+
+CONTENTS_WITH_BASE["files"].update(EXTRA_CONTENTS)
+
+
+def result_with_base(results):
+    result = {mozpath.join("base/root", p): v for p, v in six.iteritems(results)}
+    result.update(EXTRA_CONTENTS)
+    return result
+
+
+RESULT_FLAT_WITH_BASE = result_with_base(RESULT_FLAT)
+RESULT_JAR_WITH_BASE = result_with_base(RESULT_JAR)
+RESULT_OMNIJAR_WITH_BASE = result_with_base(RESULT_OMNIJAR)
+
+
+def fill_formatter(formatter, contents):
+    for base, is_addon in sorted(contents["bases"].items()):
+        formatter.add_base(base, is_addon)
+
+    for manifest in contents["manifests"]:
+        formatter.add_manifest(manifest)
+
+    for k, v in sorted(six.iteritems(contents["files"])):
+        if k.endswith(".xpt"):
+            formatter.add_interfaces(k, v)
+        else:
+            formatter.add(k, v)
+
+
+def get_contents(registry, read_all=False, mode="rt"):
+    result = {}
+    for k, v in registry:
+        if isinstance(v, FileRegistry):
+            result[k] = get_contents(v)
+        elif isinstance(v, ManifestFile) or read_all:
+            if "b" in mode:
+                result[k] = v.open().read()
+            else:
+                result[k] = six.ensure_text(v.open().read()).splitlines()
+        else:
+            result[k] = v
+    return result
+
+
+class TestFormatters(TestErrors, unittest.TestCase):
+    maxDiff = None
+
+    def test_bases(self):
+        formatter = FlatFormatter(FileRegistry())
+        formatter.add_base("")
+        formatter.add_base("addon0", addon=True)
+        formatter.add_base("browser")
+        self.assertEqual(formatter._get_base("platform.ini"), ("", "platform.ini"))
+        self.assertEqual(
+            formatter._get_base("browser/application.ini"),
+            ("browser", "application.ini"),
+        )
+        self.assertEqual(
+            formatter._get_base("addon0/install.rdf"), ("addon0", "install.rdf")
+        )
+
+    def do_test_contents(self, formatter, contents):
+        for f in contents["files"]:
+            # .xpt files are merged, so skip them.
+            if not f.endswith(".xpt"):
+                self.assertTrue(formatter.contains(f))
+
+    def test_flat_formatter(self):
+        registry = FileRegistry()
+        formatter = FlatFormatter(registry)
+
+        fill_formatter(formatter, CONTENTS)
+        self.assertEqual(get_contents(registry), RESULT_FLAT)
+        self.do_test_contents(formatter, CONTENTS)
+
+    def test_jar_formatter(self):
+        registry = FileRegistry()
+        formatter = JarFormatter(registry)
+
+        fill_formatter(formatter, CONTENTS)
+        self.assertEqual(get_contents(registry), RESULT_JAR)
+        self.do_test_contents(formatter, CONTENTS)
+
+    def test_omnijar_formatter(self):
+        registry = FileRegistry()
+        formatter = OmniJarFormatter(registry, "omni.foo")
+
+        fill_formatter(formatter, CONTENTS)
+        self.assertEqual(get_contents(registry), RESULT_OMNIJAR)
+        self.do_test_contents(formatter, CONTENTS)
+
+    def test_flat_formatter_with_base(self):
+        registry = FileRegistry()
+        formatter = FlatFormatter(registry)
+
+        fill_formatter(formatter, CONTENTS_WITH_BASE)
+        self.assertEqual(get_contents(registry), RESULT_FLAT_WITH_BASE)
+        self.do_test_contents(formatter, CONTENTS_WITH_BASE)
+
+    def test_jar_formatter_with_base(self):
+        registry = FileRegistry()
+        formatter = JarFormatter(registry)
+
+        fill_formatter(formatter, CONTENTS_WITH_BASE)
+        self.assertEqual(get_contents(registry), RESULT_JAR_WITH_BASE)
+        self.do_test_contents(formatter, CONTENTS_WITH_BASE)
+
+    def test_omnijar_formatter_with_base(self):
+        registry = FileRegistry()
+        formatter = OmniJarFormatter(registry, "omni.foo")
+
+        fill_formatter(formatter, CONTENTS_WITH_BASE)
+        self.assertEqual(get_contents(registry), RESULT_OMNIJAR_WITH_BASE)
+        self.do_test_contents(formatter, CONTENTS_WITH_BASE)
+
+    def test_omnijar_formatter_with_subpath(self):
+        registry = FileRegistry()
+        formatter = OmniJarFormatter(registry, "bar/omni.foo")
+
+        fill_formatter(formatter, CONTENTS)
+        self.assertEqual(get_contents(registry), RESULT_OMNIJAR_WITH_SUBPATH)
+        self.do_test_contents(formatter, CONTENTS)
+
+    def test_omnijar_is_resource(self):
+        def is_resource(base, path):
+            registry = FileRegistry()
+            f = OmniJarFormatter(
+                registry,
+                "omni.foo",
+                non_resources=[
+                    "defaults/messenger/mailViews.dat",
+                    "defaults/foo/*",
+                    "*/dummy",
+                ],
+            )
+            f.add_base("")
+            f.add_base("app")
+            f.add(mozpath.join(base, path), GeneratedFile(b""))
+            if f.copier.contains(mozpath.join(base, path)):
+                return False
+            self.assertTrue(f.copier.contains(mozpath.join(base, "omni.foo")))
+            self.assertTrue(f.copier[mozpath.join(base, "omni.foo")].contains(path))
+            return True
+
+        for base in ["", "app/"]:
+            self.assertTrue(is_resource(base, "chrome"))
+            self.assertTrue(is_resource(base, "chrome/foo/bar/baz.properties"))
+            self.assertFalse(is_resource(base, "chrome/icons/foo.png"))
+            self.assertTrue(is_resource(base, "components/foo.js"))
+            self.assertFalse(is_resource(base, "components/foo.so"))
+            self.assertTrue(is_resource(base, "res/foo.css"))
+            self.assertFalse(is_resource(base, "res/cursors/foo.png"))
+            self.assertFalse(is_resource(base, "res/MainMenu.nib/foo"))
+            self.assertTrue(is_resource(base, "defaults/pref/foo.js"))
+            self.assertFalse(is_resource(base, "defaults/pref/channel-prefs.js"))
+            self.assertTrue(is_resource(base, "defaults/preferences/foo.js"))
+            self.assertFalse(is_resource(base, "defaults/preferences/channel-prefs.js"))
+            self.assertTrue(is_resource(base, "modules/foo.jsm"))
+            self.assertTrue(is_resource(base, "greprefs.js"))
+            self.assertTrue(is_resource(base, "hyphenation/foo"))
+            self.assertTrue(is_resource(base, "update.locale"))
+            self.assertFalse(is_resource(base, "foo"))
+            self.assertFalse(is_resource(base, "foo/bar/greprefs.js"))
+            self.assertTrue(is_resource(base, "defaults/messenger/foo.dat"))
+            self.assertFalse(is_resource(base, "defaults/messenger/mailViews.dat"))
+            self.assertTrue(is_resource(base, "defaults/pref/foo.js"))
+            self.assertFalse(is_resource(base, "defaults/foo/bar.dat"))
+            self.assertFalse(is_resource(base, "defaults/foo/bar/baz.dat"))
+            self.assertTrue(is_resource(base, "chrome/foo/bar/baz/dummy_"))
+            self.assertFalse(is_resource(base, "chrome/foo/bar/baz/dummy"))
+            self.assertTrue(is_resource(base, "chrome/foo/bar/dummy_"))
+            self.assertFalse(is_resource(base, "chrome/foo/bar/dummy"))
+
+    def test_chrome_override(self):
+        registry = FileRegistry()
+        f = FlatFormatter(registry)
+        f.add_base("")
+        f.add_manifest(ManifestContent("chrome", "foo", "foo/unix"))
+        # A more specific entry for a given chrome name can override a more
+        # generic one.
+        f.add_manifest(ManifestContent("chrome", "foo", "foo/win", "os=WINNT"))
+        f.add_manifest(ManifestContent("chrome", "foo", "foo/osx", "os=Darwin"))
+
+        # Chrome with the same name overrides the previous registration.
+        with self.assertRaises(ErrorMessage) as e:
+            f.add_manifest(ManifestContent("chrome", "foo", "foo/"))
+
+        self.assertEqual(
+            str(e.exception),
+            'error: "content foo foo/" overrides ' '"content foo foo/unix"',
+        )
+
+        # Chrome with the same name and same flags overrides the previous
+        # registration.
+        with self.assertRaises(ErrorMessage) as e:
+            f.add_manifest(ManifestContent("chrome", "foo", "foo/", "os=WINNT"))
+
+        self.assertEqual(
+            str(e.exception),
+            'error: "content foo foo/ os=WINNT" overrides '
+            '"content foo foo/win os=WINNT"',
+        )
+
+        # We may start with the more specific entry first
+        f.add_manifest(ManifestContent("chrome", "bar", "bar/win", "os=WINNT"))
+        # Then adding a more generic one overrides it.
+        with self.assertRaises(ErrorMessage) as e:
+            f.add_manifest(ManifestContent("chrome", "bar", "bar/unix"))
+
+        self.assertEqual(
+            str(e.exception),
+            'error: "content bar bar/unix" overrides ' '"content bar bar/win os=WINNT"',
+        )
+
+        # Adding something more specific still works.
+        f.add_manifest(
+            ManifestContent("chrome", "bar", "bar/win", "os=WINNT osversion>=7.0")
+        )
+
+        # Variations of skin/locales are allowed.
+        f.add_manifest(
+            ManifestSkin("chrome", "foo", "classic/1.0", "foo/skin/classic/")
+        )
+        f.add_manifest(ManifestSkin("chrome", "foo", "modern/1.0", "foo/skin/modern/"))
+
+        f.add_manifest(ManifestLocale("chrome", "foo", "en-US", "foo/locale/en-US/"))
+        f.add_manifest(ManifestLocale("chrome", "foo", "ja-JP", "foo/locale/ja-JP/"))
+
+        # But same-skin/locale still error out.
+        with self.assertRaises(ErrorMessage) as e:
+            f.add_manifest(
+                ManifestSkin("chrome", "foo", "classic/1.0", "foo/skin/classic/foo")
+            )
+
+        self.assertEqual(
+            str(e.exception),
+            'error: "skin foo classic/1.0 foo/skin/classic/foo" overrides '
+            '"skin foo classic/1.0 foo/skin/classic/"',
+        )
+
+        with self.assertRaises(ErrorMessage) as e:
+            f.add_manifest(
+                ManifestLocale("chrome", "foo", "en-US", "foo/locale/en-US/foo")
+            )
+
+        self.assertEqual(
+            str(e.exception),
+            'error: "locale foo en-US foo/locale/en-US/foo" overrides '
+            '"locale foo en-US foo/locale/en-US/"',
+        )
+
+        # Duplicating existing manifest entries is not an error.
+        f.add_manifest(ManifestContent("chrome", "foo", "foo/unix"))
+
+        self.assertEqual(
+            self.get_output(),
+            [
+                'warning: "content foo foo/unix" is duplicated. Skipping.',
+            ],
+        )
+
+
+if __name__ == "__main__":
+    mozunit.main()
diff --git a/python/mozbuild/mozpack/test/test_packager_l10n.py b/python/mozbuild/mozpack/test/test_packager_l10n.py
new file mode 100644
index 0000000000..0714ae3252
--- /dev/null
+++ b/python/mozbuild/mozpack/test/test_packager_l10n.py
@@ -0,0 +1,153 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+import unittest
+
+import mozunit
+import six
+
+from mozpack.chrome.manifest import Manifest, ManifestContent, ManifestLocale
+from mozpack.copier import FileRegistry
+from mozpack.files import GeneratedFile, ManifestFile
+from mozpack.packager import l10n
+from test_packager import MockFinder
+
+
+class TestL10NRepack(unittest.TestCase):
+    def test_l10n_repack(self):
+        foo = GeneratedFile(b"foo")
+        foobar = GeneratedFile(b"foobar")
+        qux = GeneratedFile(b"qux")
+        bar = GeneratedFile(b"bar")
+        baz = GeneratedFile(b"baz")
+        dict_aa = GeneratedFile(b"dict_aa")
+        dict_bb = GeneratedFile(b"dict_bb")
+        dict_cc = GeneratedFile(b"dict_cc")
+        barbaz = GeneratedFile(b"barbaz")
+        lst = GeneratedFile(b"foo\nbar")
+        app_finder = MockFinder(
+            {
+                "bar/foo": foo,
+                "chrome/foo/foobar": foobar,
+                "chrome/qux/qux.properties": qux,
+                "chrome/qux/baz/baz.properties": baz,
+                "chrome/chrome.manifest": ManifestFile(
+                    "chrome",
+                    [
+                        ManifestContent("chrome", "foo", "foo/"),
+                        ManifestLocale("chrome", "qux", "en-US", "qux/"),
+                    ],
+                ),
+                "chrome.manifest": ManifestFile(
+                    "", [Manifest("", "chrome/chrome.manifest")]
+                ),
+                "dict/aa": dict_aa,
+                "app/chrome/bar/barbaz.dtd": barbaz,
+                "app/chrome/chrome.manifest": ManifestFile(
+                    "app/chrome", [ManifestLocale("app/chrome", "bar", "en-US", "bar/")]
+                ),
+                "app/chrome.manifest": ManifestFile(
+                    "app", [Manifest("app", "chrome/chrome.manifest")]
+                ),
+                "app/dict/bb": dict_bb,
+                "app/dict/cc": dict_cc,
+                "app/chrome/bar/search/foo.xml": foo,
+                "app/chrome/bar/search/bar.xml": bar,
+                "app/chrome/bar/search/lst.txt": lst,
+                "META-INF/foo": foo,  # Stripped.
+                "inner/META-INF/foo": foo,  # Not stripped.
+                "app/META-INF/foo": foo,  # Stripped.
+                "app/inner/META-INF/foo": foo,  # Not stripped.
+            }
+        )
+        app_finder.jarlogs = {}
+        app_finder.base = "app"
+        foo_l10n = GeneratedFile(b"foo_l10n")
+        qux_l10n = GeneratedFile(b"qux_l10n")
+        baz_l10n = GeneratedFile(b"baz_l10n")
+        barbaz_l10n = GeneratedFile(b"barbaz_l10n")
+        lst_l10n = GeneratedFile(b"foo\nqux")
+        l10n_finder = MockFinder(
+            {
+                "chrome/qux-l10n/qux.properties": qux_l10n,
+                "chrome/qux-l10n/baz/baz.properties": baz_l10n,
+                "chrome/chrome.manifest": ManifestFile(
+                    "chrome",
+                    [
+                        ManifestLocale("chrome", "qux", "x-test", "qux-l10n/"),
+                    ],
+                ),
+                "chrome.manifest": ManifestFile(
+                    "", [Manifest("", "chrome/chrome.manifest")]
+                ),
+                "dict/bb": dict_bb,
+                "dict/cc": dict_cc,
+                "app/chrome/bar-l10n/barbaz.dtd": barbaz_l10n,
+                "app/chrome/chrome.manifest": ManifestFile(
+                    "app/chrome",
+                    [ManifestLocale("app/chrome", "bar", "x-test", "bar-l10n/")],
+                ),
+                "app/chrome.manifest": ManifestFile(
+                    "app", [Manifest("app", "chrome/chrome.manifest")]
+                ),
+                "app/dict/aa": dict_aa,
+                "app/chrome/bar-l10n/search/foo.xml": foo_l10n,
+                "app/chrome/bar-l10n/search/qux.xml": qux_l10n,
+                "app/chrome/bar-l10n/search/lst.txt": lst_l10n,
+            }
+        )
+        l10n_finder.base = "l10n"
+        copier = FileRegistry()
+        formatter = l10n.FlatFormatter(copier)
+
+        l10n._repack(
+            app_finder,
+            l10n_finder,
+            copier,
+            formatter,
+            ["dict", "chrome/**/search/*.xml"],
+        )
+        self.maxDiff = None
+
+        repacked = {
+            "bar/foo": foo,
+            "chrome/foo/foobar": foobar,
+            "chrome/qux-l10n/qux.properties": qux_l10n,
+            "chrome/qux-l10n/baz/baz.properties": baz_l10n,
+            "chrome/chrome.manifest": ManifestFile(
+                "chrome",
+                [
+                    ManifestContent("chrome", "foo", "foo/"),
+                    ManifestLocale("chrome", "qux", "x-test", "qux-l10n/"),
+                ],
+            ),
+            "chrome.manifest": ManifestFile(
+                "", [Manifest("", "chrome/chrome.manifest")]
+            ),
+            "dict/bb": dict_bb,
+            "dict/cc": dict_cc,
+            "app/chrome/bar-l10n/barbaz.dtd": barbaz_l10n,
+            "app/chrome/chrome.manifest": ManifestFile(
+                "app/chrome",
+                [ManifestLocale("app/chrome", "bar", "x-test", "bar-l10n/")],
+            ),
+            "app/chrome.manifest": ManifestFile(
+                "app", [Manifest("app", "chrome/chrome.manifest")]
+            ),
+            "app/dict/aa": dict_aa,
+            "app/chrome/bar-l10n/search/foo.xml": foo_l10n,
+            "app/chrome/bar-l10n/search/qux.xml": qux_l10n,
+            "app/chrome/bar-l10n/search/lst.txt": lst_l10n,
+            "inner/META-INF/foo": foo,
+            "app/inner/META-INF/foo": foo,
+        }
+
+        self.assertEqual(
+            dict((p, f.open().read()) for p, f in copier),
+            dict((p, f.open().read()) for p, f in six.iteritems(repacked)),
+        )
+
+
+if __name__ == "__main__":
+    mozunit.main()
diff --git a/python/mozbuild/mozpack/test/test_packager_unpack.py b/python/mozbuild/mozpack/test/test_packager_unpack.py
new file mode 100644
index 0000000000..57a2d71eda
--- /dev/null
+++ b/python/mozbuild/mozpack/test/test_packager_unpack.py
@@ -0,0 +1,67 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+import mozunit
+
+from mozpack.copier import FileCopier, FileRegistry
+from mozpack.packager.formats import FlatFormatter, JarFormatter, OmniJarFormatter
+from mozpack.packager.unpack import unpack_to_registry
+from mozpack.test.test_files import TestWithTmpDir
+from mozpack.test.test_packager_formats import CONTENTS, fill_formatter, get_contents
+
+
+class TestUnpack(TestWithTmpDir):
+    maxDiff = None
+
+    @staticmethod
+    def _get_copier(cls):
+        copier = FileCopier()
+        formatter = cls(copier)
+        fill_formatter(formatter, CONTENTS)
+        return copier
+
+    @classmethod
+    def setUpClass(cls):
+        cls.contents = get_contents(
+            cls._get_copier(FlatFormatter), read_all=True, mode="rb"
+        )
+
+    def _unpack_test(self, cls):
+        # Format a package with the given formatter class
+        copier = self._get_copier(cls)
+        copier.copy(self.tmpdir)
+
+        # Unpack that package. Its content is expected to match that of a Flat
+        # formatted package.
+        registry = FileRegistry()
+        unpack_to_registry(self.tmpdir, registry, getattr(cls, "OMNIJAR_NAME", None))
+        self.assertEqual(
+            get_contents(registry, read_all=True, mode="rb"), self.contents
+        )
+
+    def test_flat_unpack(self):
+        self._unpack_test(FlatFormatter)
+
+    def test_jar_unpack(self):
+        self._unpack_test(JarFormatter)
+
+    @staticmethod
+    def _omni_foo_formatter(name):
+        class OmniFooFormatter(OmniJarFormatter):
+            OMNIJAR_NAME = name
+
+            def __init__(self, registry):
+                super(OmniFooFormatter, self).__init__(registry, name)
+
+        return OmniFooFormatter
+
+    def test_omnijar_unpack(self):
+        self._unpack_test(self._omni_foo_formatter("omni.foo"))
+
+    def test_omnijar_subpath_unpack(self):
+        self._unpack_test(self._omni_foo_formatter("bar/omni.foo"))
+
+
+if __name__ == "__main__":
+    mozunit.main()
diff --git a/python/mozbuild/mozpack/test/test_path.py b/python/mozbuild/mozpack/test/test_path.py
new file mode 100644
index 0000000000..6c7aeb5400
--- /dev/null
+++ b/python/mozbuild/mozpack/test/test_path.py
@@ -0,0 +1,152 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+import os
+import unittest
+
+import mozunit
+
+from mozpack.path import (
+    basedir,
+    basename,
+    commonprefix,
+    dirname,
+    join,
+    match,
+    normpath,
+    rebase,
+    relpath,
+    split,
+    splitext,
+)
+
+
+class TestPath(unittest.TestCase):
+    SEP = os.sep
+
+    def test_relpath(self):
+        self.assertEqual(relpath("foo", "foo"), "")
+        self.assertEqual(relpath(self.SEP.join(("foo", "bar")), "foo/bar"), "")
+        self.assertEqual(relpath(self.SEP.join(("foo", "bar")), "foo"), "bar")
+        self.assertEqual(
+            relpath(self.SEP.join(("foo", "bar", "baz")), "foo"), "bar/baz"
+        )
+        self.assertEqual(relpath(self.SEP.join(("foo", "bar")), "foo/bar/baz"), "..")
+        self.assertEqual(relpath(self.SEP.join(("foo", "bar")), "foo/baz"), "../bar")
+        self.assertEqual(relpath("foo/", "foo"), "")
+        self.assertEqual(relpath("foo/bar/", "foo"), "bar")
+
+    def test_join(self):
+        self.assertEqual(join("foo", "bar", "baz"), "foo/bar/baz")
+        self.assertEqual(join("foo", "", "bar"), "foo/bar")
+        self.assertEqual(join("", "foo", "bar"), "foo/bar")
+        self.assertEqual(join("", "foo", "/bar"), "/bar")
+
+    def test_normpath(self):
+        self.assertEqual(
+            normpath(self.SEP.join(("foo", "bar", "baz", "..", "qux"))), "foo/bar/qux"
+        )
+
+    def test_dirname(self):
+        self.assertEqual(dirname("foo/bar/baz"), "foo/bar")
+        self.assertEqual(dirname("foo/bar"), "foo")
+        self.assertEqual(dirname("foo"), "")
+        self.assertEqual(dirname("foo/bar/"), "foo/bar")
+
+    def test_commonprefix(self):
+        self.assertEqual(
+            commonprefix(
+                [self.SEP.join(("foo", "bar", "baz")), "foo/qux", "foo/baz/qux"]
+            ),
+            "foo/",
+        )
+        self.assertEqual(
+            commonprefix([self.SEP.join(("foo", "bar", "baz")), "foo/qux", "baz/qux"]),
+            "",
+        )
+
+    def test_basename(self):
+        self.assertEqual(basename("foo/bar/baz"), "baz")
+        self.assertEqual(basename("foo/bar"), "bar")
+        self.assertEqual(basename("foo"), "foo")
+        self.assertEqual(basename("foo/bar/"), "")
+
+    def test_split(self):
+        self.assertEqual(
+            split(self.SEP.join(("foo", "bar", "baz"))), ["foo", "bar", "baz"]
+        )
+
+    def test_splitext(self):
+        self.assertEqual(
+            splitext(self.SEP.join(("foo", "bar", "baz.qux"))), ("foo/bar/baz", ".qux")
+        )
+
+    def test_basedir(self):
+        foobarbaz = self.SEP.join(("foo", "bar", "baz"))
+        self.assertEqual(basedir(foobarbaz, ["foo", "bar", "baz"]), "foo")
+        self.assertEqual(basedir(foobarbaz, ["foo", "foo/bar", "baz"]), "foo/bar")
+        self.assertEqual(basedir(foobarbaz, ["foo/bar", "foo", "baz"]), "foo/bar")
+        self.assertEqual(basedir(foobarbaz, ["foo", "bar", ""]), "foo")
+        self.assertEqual(basedir(foobarbaz, ["bar", "baz", ""]), "")
+
+    def test_match(self):
+        self.assertTrue(match("foo", ""))
+        self.assertTrue(match("foo/bar/baz.qux", "foo/bar"))
+        self.assertTrue(match("foo/bar/baz.qux", "foo"))
+        self.assertTrue(match("foo", "*"))
+        self.assertTrue(match("foo/bar/baz.qux", "foo/bar/*"))
+        self.assertTrue(match("foo/bar/baz.qux", "foo/bar/*"))
+        self.assertTrue(match("foo/bar/baz.qux", "foo/bar/*"))
+        self.assertTrue(match("foo/bar/baz.qux", "foo/bar/*"))
+        self.assertTrue(match("foo/bar/baz.qux", "foo/*/baz.qux"))
+        self.assertTrue(match("foo/bar/baz.qux", "*/bar/baz.qux"))
+        self.assertTrue(match("foo/bar/baz.qux", "*/*/baz.qux"))
+        self.assertTrue(match("foo/bar/baz.qux", "*/*/*"))
+        self.assertTrue(match("foo/bar/baz.qux", "foo/*/*"))
+        self.assertTrue(match("foo/bar/baz.qux", "foo/*/*.qux"))
+        self.assertTrue(match("foo/bar/baz.qux", "foo/b*/*z.qux"))
+        self.assertTrue(match("foo/bar/baz.qux", "foo/b*r/ba*z.qux"))
+        self.assertFalse(match("foo/bar/baz.qux", "foo/b*z/ba*r.qux"))
+        self.assertTrue(match("foo/bar/baz.qux", "**"))
+        self.assertTrue(match("foo/bar/baz.qux", "**/baz.qux"))
+        self.assertTrue(match("foo/bar/baz.qux", "**/bar/baz.qux"))
+        self.assertTrue(match("foo/bar/baz.qux", "foo/**/baz.qux"))
+        self.assertTrue(match("foo/bar/baz.qux", "foo/**/*.qux"))
+        self.assertTrue(match("foo/bar/baz.qux", "**/foo/bar/baz.qux"))
+        self.assertTrue(match("foo/bar/baz.qux", "foo/**/bar/baz.qux"))
+        self.assertTrue(match("foo/bar/baz.qux", "foo/**/bar/*.qux"))
+        self.assertTrue(match("foo/bar/baz.qux", "foo/**/*.qux"))
+        self.assertTrue(match("foo/bar/baz.qux", "**/*.qux"))
+        self.assertFalse(match("foo/bar/baz.qux", "**.qux"))
+        self.assertFalse(match("foo/bar", "foo/*/bar"))
+        self.assertTrue(match("foo/bar/baz.qux", "foo/**/bar/**"))
+        self.assertFalse(match("foo/nobar/baz.qux", "foo/**/bar/**"))
+        self.assertTrue(match("foo/bar", "foo/**/bar/**"))
+
+    def test_rebase(self):
+        self.assertEqual(rebase("foo", "foo/bar", "bar/baz"), "baz")
+        self.assertEqual(rebase("foo", "foo", "bar/baz"), "bar/baz")
+        self.assertEqual(rebase("foo/bar", "foo", "baz"), "bar/baz")
+
+
+if os.altsep:
+
+    class TestAltPath(TestPath):
+        SEP = os.altsep
+
+    class TestReverseAltPath(TestPath):
+        def setUp(self):
+            sep = os.sep
+            os.sep = os.altsep
+            os.altsep = sep
+
+        def tearDown(self):
+            self.setUp()
+
+    class TestAltReverseAltPath(TestReverseAltPath):
+        SEP = os.altsep
+
+
+if __name__ == "__main__":
+    mozunit.main()
diff --git a/python/mozbuild/mozpack/test/test_pkg.py b/python/mozbuild/mozpack/test/test_pkg.py
new file mode 100644
index 0000000000..f1febbbae0
--- /dev/null
+++ b/python/mozbuild/mozpack/test/test_pkg.py
@@ -0,0 +1,138 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+from pathlib import Path
+from string import Template
+from unittest.mock import patch
+
+import mozunit
+
+import mozpack.pkg
+from mozpack.pkg import (
+    create_bom,
+    create_payload,
+    create_pkg,
+    get_app_info_plist,
+    get_apple_template,
+    get_relative_glob_list,
+    save_text_file,
+    xar_package_folder,
+)
+from mozpack.test.test_files import TestWithTmpDir
+
+
+class TestPkg(TestWithTmpDir):
+    maxDiff = None
+
+    class MockSubprocessRun:
+        stderr = ""
+        stdout = ""
+        returncode = 0
+
+        def __init__(self, returncode=0):
+            self.returncode = returncode
+
+    def _mk_test_file(self, name, mode=0o777):
+        tool = Path(self.tmpdir) / f"{name}"
+        tool.touch()
+        tool.chmod(mode)
+        return tool
+
+    def test_get_apple_template(self):
+        tmpl = get_apple_template("Distribution.template")
+        assert type(tmpl) == Template
+
+    def test_get_apple_template_not_file(self):
+        with self.assertRaises(Exception):
+            get_apple_template("tmpl-should-not-exist")
+
+    def test_save_text_file(self):
+        content = "Hello"
+        destination = Path(self.tmpdir) / "test_save_text_file"
+        save_text_file(content, destination)
+        with destination.open("r") as file:
+            assert content == file.read()
+
+    def test_get_app_info_plist(self):
+        app_path = Path(self.tmpdir) / "app"
+        (app_path / "Contents").mkdir(parents=True)
+        (app_path / "Contents/Info.plist").touch()
+        data = {"foo": "bar"}
+        with patch.object(mozpack.pkg.plistlib, "load", lambda x: data):
+            assert data == get_app_info_plist(app_path)
+
+    def test_get_app_info_plist_not_file(self):
+        app_path = Path(self.tmpdir) / "app-does-not-exist"
+        with self.assertRaises(Exception):
+            get_app_info_plist(app_path)
+
+    def _mock_payload(self, returncode):
+        def _mock_run(*args, **kwargs):
+            return self.MockSubprocessRun(returncode)
+
+        return _mock_run
+
+    def test_create_payload(self):
+        destination = Path(self.tmpdir) / "mockPayload"
+        with patch.object(mozpack.pkg.subprocess, "run", self._mock_payload(0)):
+            create_payload(destination, Path(self.tmpdir), "cpio")
+
+    def test_create_bom(self):
+        bom_path = Path(self.tmpdir) / "Bom"
+        bom_path.touch()
+        root_path = Path(self.tmpdir)
+        tool_path = Path(self.tmpdir) / "not-really-used-during-test"
+        with patch.object(mozpack.pkg.subprocess, "check_call", lambda *x: None):
+            create_bom(bom_path, root_path, tool_path)
+
+    def get_relative_glob_list(self):
+        source = Path(self.tmpdir)
+        (source / "testfile").touch()
+        glob = "*"
+        assert len(get_relative_glob_list(source, glob)) == 1
+
+    def test_xar_package_folder(self):
+        source = Path(self.tmpdir)
+        dest = source / "fakedestination"
+        dest.touch()
+        tool = source / "faketool"
+        with patch.object(mozpack.pkg.subprocess, "check_call", lambda *x, **y: None):
+            xar_package_folder(source, dest, tool)
+
+    def test_xar_package_folder_not_absolute(self):
+        source = Path("./some/relative/path")
+        dest = Path("./some/other/relative/path")
+        tool = source / "faketool"
+        with patch.object(mozpack.pkg.subprocess, "check_call", lambda: None):
+            with self.assertRaises(Exception):
+                xar_package_folder(source, dest, tool)
+
+    def test_create_pkg(self):
+        def noop(*x, **y):
+            pass
+
+        def mock_get_app_info_plist(*args):
+            return {"CFBundleShortVersionString": "1.0.0"}
+
+        def mock_get_apple_template(*args):
+            return Template("fake template")
+
+        source = Path(self.tmpdir) / "FakeApp.app"
+        source.mkdir()
+        output = Path(self.tmpdir) / "output.pkg"
+        fake_tool = Path(self.tmpdir) / "faketool"
+        with patch.multiple(
+            mozpack.pkg,
+            get_app_info_plist=mock_get_app_info_plist,
+            get_apple_template=mock_get_apple_template,
+            save_text_file=noop,
+            create_payload=noop,
+            create_bom=noop,
+            xar_package_folder=noop,
+        ):
+            create_pkg(source, output, fake_tool, fake_tool, fake_tool)
+
+
+if __name__ == "__main__":
+    mozunit.main()
diff --git a/python/mozbuild/mozpack/test/test_unify.py b/python/mozbuild/mozpack/test/test_unify.py
new file mode 100644
index 0000000000..15de50dccc
--- /dev/null
+++ b/python/mozbuild/mozpack/test/test_unify.py
@@ -0,0 +1,250 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+import os
+import sys
+from io import StringIO
+
+import mozunit
+
+from mozbuild.util import ensureParentDir
+from mozpack.errors import AccumulatedErrors, ErrorMessage, errors
+from mozpack.files import FileFinder
+from mozpack.mozjar import JarWriter
+from mozpack.test.test_files import MockDest, TestWithTmpDir
+from mozpack.unify import UnifiedBuildFinder, UnifiedFinder
+
+
+class TestUnified(TestWithTmpDir):
+    def create_one(self, which, path, content):
+        file = self.tmppath(os.path.join(which, path))
+        ensureParentDir(file)
+        if isinstance(content, str):
+            content = content.encode("utf-8")
+        open(file, "wb").write(content)
+
+    def create_both(self, path, content):
+        for p in ["a", "b"]:
+            self.create_one(p, path, content)
+
+
+class TestUnifiedFinder(TestUnified):
+    def test_unified_finder(self):
+        self.create_both("foo/bar", "foobar")
+        self.create_both("foo/baz", "foobaz")
+        self.create_one("a", "bar", "bar")
+        self.create_one("b", "baz", "baz")
+        self.create_one("a", "qux", "foobar")
+        self.create_one("b", "qux", "baz")
+        self.create_one("a", "test/foo", "a\nb\nc\n")
+        self.create_one("b", "test/foo", "b\nc\na\n")
+        self.create_both("test/bar", "a\nb\nc\n")
+
+        finder = UnifiedFinder(
+            FileFinder(self.tmppath("a")),
+            FileFinder(self.tmppath("b")),
+            sorted=["test"],
+        )
+        self.assertEqual(
+            sorted(
+                [(f, c.open().read().decode("utf-8")) for f, c in finder.find("foo")]
+            ),
+            [("foo/bar", "foobar"), ("foo/baz", "foobaz")],
+        )
+        self.assertRaises(ErrorMessage, any, finder.find("bar"))
+        self.assertRaises(ErrorMessage, any, finder.find("baz"))
+        self.assertRaises(ErrorMessage, any, finder.find("qux"))
+        self.assertEqual(
+            sorted(
+                [(f, c.open().read().decode("utf-8")) for f, c in finder.find("test")]
+            ),
+            [("test/bar", "a\nb\nc\n"), ("test/foo", "a\nb\nc\n")],
+        )
+
+
+class TestUnifiedBuildFinder(TestUnified):
+    def test_unified_build_finder(self):
+        finder = UnifiedBuildFinder(
+            FileFinder(self.tmppath("a")), FileFinder(self.tmppath("b"))
+        )
+
+        # Test chrome.manifest unification
+        self.create_both("chrome.manifest", "a\nb\nc\n")
+        self.create_one("a", "chrome/chrome.manifest", "a\nb\nc\n")
+        self.create_one("b", "chrome/chrome.manifest", "b\nc\na\n")
+        self.assertEqual(
+            sorted(
+                [
+                    (f, c.open().read().decode("utf-8"))
+                    for f, c in finder.find("**/chrome.manifest")
+                ]
+            ),
+            [("chrome.manifest", "a\nb\nc\n"), ("chrome/chrome.manifest", "a\nb\nc\n")],
+        )
+
+        # Test buildconfig.html unification
+        self.create_one(
+            "a",
+            "chrome/browser/foo/buildconfig.html",
+            "\n".join(
+                [
+                    "<html>",
+                    "  <body>",
+                    "    <div>",
+                    "      <h1>Build Configuration</h1>",
+                    "      <div>foo</div>",
+                    "    </div>",
+                    "  </body>",
+                    "</html>",
+                ]
+            ),
+        )
+        self.create_one(
+            "b",
+            "chrome/browser/foo/buildconfig.html",
+            "\n".join(
+                [
+                    "<html>",
+                    "  <body>",
+                    "    <div>",
+                    "      <h1>Build Configuration</h1>",
+                    "      <div>bar</div>",
+                    "    </div>",
+                    "  </body>",
+                    "</html>",
+                ]
+            ),
+        )
+        self.assertEqual(
+            sorted(
+                [
+                    (f, c.open().read().decode("utf-8"))
+                    for f, c in finder.find("**/buildconfig.html")
+                ]
+            ),
+            [
+                (
+                    "chrome/browser/foo/buildconfig.html",
+                    "\n".join(
+                        [
+                            "<html>",
+                            "  <body>",
+                            "    <div>",
+                            "      <h1>Build Configuration</h1>",
+                            "      <div>foo</div>",
+                            "      <hr> </hr>",
+                            "      <div>bar</div>",
+                            "    </div>",
+                            "  </body>",
+                            "</html>",
+                        ]
+                    ),
+                )
+            ],
+        )
+
+        # Test xpi file unification
+        xpi = MockDest()
+        with JarWriter(fileobj=xpi, compress=True) as jar:
+            jar.add("foo", "foo")
+            jar.add("bar", "bar")
+        foo_xpi = xpi.read()
+        self.create_both("foo.xpi", foo_xpi)
+
+        with JarWriter(fileobj=xpi, compress=True) as jar:
+            jar.add("foo", "bar")
+        self.create_one("a", "bar.xpi", foo_xpi)
+        self.create_one("b", "bar.xpi", xpi.read())
+
+        errors.out = StringIO()
+        with self.assertRaises(AccumulatedErrors), errors.accumulate():
+            self.assertEqual(
+                [(f, c.open().read()) for f, c in finder.find("*.xpi")],
+                [("foo.xpi", foo_xpi)],
+            )
+        errors.out = sys.stderr
+
+        # Test install.rdf unification
+        x86_64 = "Darwin_x86_64-gcc3"
+        x86 = "Darwin_x86-gcc3"
+        target_tag = "<{em}targetPlatform>{platform}</{em}targetPlatform>"
+        target_attr = '{em}targetPlatform="{platform}" '
+
+        rdf_tag = "".join(
+            [
+                '<{RDF}Description {em}bar="bar" {em}qux="qux">',
+                "<{em}foo>foo</{em}foo>",
+                "{targets}",
+                "<{em}baz>baz</{em}baz>",
+                "</{RDF}Description>",
+            ]
+        )
+        rdf_attr = "".join(
+            [
+                '<{RDF}Description {em}bar="bar" {attr}{em}qux="qux">',
+                "{targets}",
+                "<{em}foo>foo</{em}foo><{em}baz>baz</{em}baz>",
+                "</{RDF}Description>",
+            ]
+        )
+
+        for descr_ns, target_ns in (("RDF:", ""), ("", "em:"), ("RDF:", "em:")):
+            # First we need to infuse the above strings with our namespaces and
+            # platform values.
+            ns = {"RDF": descr_ns, "em": target_ns}
+            target_tag_x86_64 = target_tag.format(platform=x86_64, **ns)
+            target_tag_x86 = target_tag.format(platform=x86, **ns)
+            target_attr_x86_64 = target_attr.format(platform=x86_64, **ns)
+            target_attr_x86 = target_attr.format(platform=x86, **ns)
+
+            tag_x86_64 = rdf_tag.format(targets=target_tag_x86_64, **ns)
+            tag_x86 = rdf_tag.format(targets=target_tag_x86, **ns)
+            tag_merged = rdf_tag.format(
+                targets=target_tag_x86_64 + target_tag_x86, **ns
+            )
+            tag_empty = rdf_tag.format(targets="", **ns)
+
+            attr_x86_64 = rdf_attr.format(attr=target_attr_x86_64, targets="", **ns)
+            attr_x86 = rdf_attr.format(attr=target_attr_x86, targets="", **ns)
+            attr_merged = rdf_attr.format(
+                attr="", targets=target_tag_x86_64 + target_tag_x86, **ns
+            )
+
+            # This table defines the test cases, columns "a" and "b" being the
+            # contents of the install.rdf of the respective platform and
+            # "result" the exepected merged content after unification.
+            testcases = (
+                # _____a_____  _____b_____  ___result___#
+                (tag_x86_64, tag_x86, tag_merged),
+                (tag_x86_64, tag_empty, tag_empty),
+                (tag_empty, tag_x86, tag_empty),
+                (tag_empty, tag_empty, tag_empty),
+                (attr_x86_64, attr_x86, attr_merged),
+                (tag_x86_64, attr_x86, tag_merged),
+                (attr_x86_64, tag_x86, attr_merged),
+                (attr_x86_64, tag_empty, tag_empty),
+                (tag_empty, attr_x86, tag_empty),
+            )
+
+            # Now create the files from the above table and compare
+            results = []
+            for emid, (rdf_a, rdf_b, result) in enumerate(testcases):
+                filename = "ext/id{0}/install.rdf".format(emid)
+                self.create_one("a", filename, rdf_a)
+                self.create_one("b", filename, rdf_b)
+                results.append((filename, result))
+
+            self.assertEqual(
+                sorted(
+                    [
+                        (f, c.open().read().decode("utf-8"))
+                        for f, c in finder.find("**/install.rdf")
+                    ]
+                ),
+                results,
+            )
+
+
+if __name__ == "__main__":
+    mozunit.main()