Adding upstream version 110.0.1.upstream/110.0.1upstream

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

7 files changed, 1059 insertions, 0 deletions

diff --git a/toolkit/modules/subprocess/test/xpcshell/data_test_script.py b/toolkit/modules/subprocess/test/xpcshell/data_test_script.py
new file mode 100644
index 0000000000..e1f5f5de93
--- /dev/null
+++ b/toolkit/modules/subprocess/test/xpcshell/data_test_script.py
@@ -0,0 +1,59 @@
+#!/usr/bin/env python3
+
+import os
+import signal
+import struct
+import sys
+
+
+def output(line, stream=sys.stdout, print_only=False):
+    if isinstance(line, str):
+        line = line.encode("utf-8", "surrogateescape")
+    if not print_only:
+        stream.buffer.write(struct.pack("@I", len(line)))
+    stream.buffer.write(line)
+    stream.flush()
+
+
+def echo_loop():
+    while True:
+        line = sys.stdin.buffer.readline()
+        if not line:
+            break
+
+        output(line)
+
+
+if sys.platform == "win32":
+    import msvcrt
+
+    msvcrt.setmode(sys.stderr.fileno(), os.O_BINARY)
+
+
+cmd = sys.argv[1]
+if cmd == "echo":
+    echo_loop()
+elif cmd == "exit":
+    sys.exit(int(sys.argv[2]))
+elif cmd == "env":
+    for var in sys.argv[2:]:
+        output(os.environ.get(var, "!"))
+elif cmd == "pwd":
+    output(os.path.abspath(os.curdir))
+elif cmd == "print_args":
+    for arg in sys.argv[2:]:
+        output(arg)
+elif cmd == "ignore_sigterm":
+    signal.signal(signal.SIGTERM, signal.SIG_IGN)
+
+    output("Ready")
+    while True:
+        try:
+            signal.pause()
+        except AttributeError:
+            import time
+
+            time.sleep(3600)
+elif cmd == "print":
+    output(sys.argv[2], stream=sys.stdout, print_only=True)
+    output(sys.argv[3], stream=sys.stderr, print_only=True)
diff --git a/toolkit/modules/subprocess/test/xpcshell/data_text_file.txt b/toolkit/modules/subprocess/test/xpcshell/data_text_file.txt
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/toolkit/modules/subprocess/test/xpcshell/data_text_file.txt
diff --git a/toolkit/modules/subprocess/test/xpcshell/head.js b/toolkit/modules/subprocess/test/xpcshell/head.js
new file mode 100644
index 0000000000..a2b85047d3
--- /dev/null
+++ b/toolkit/modules/subprocess/test/xpcshell/head.js
@@ -0,0 +1,13 @@
+"use strict";
+
+var { XPCOMUtils } = ChromeUtils.importESModule(
+  "resource://gre/modules/XPCOMUtils.sys.mjs"
+);
+const { AppConstants } = ChromeUtils.importESModule(
+  "resource://gre/modules/AppConstants.sys.mjs"
+);
+
+// eslint-disable-next-line no-unused-vars
+ChromeUtils.defineESModuleGetters(this, {
+  Subprocess: "resource://gre/modules/Subprocess.sys.mjs",
+});
diff --git a/toolkit/modules/subprocess/test/xpcshell/test_subprocess.js b/toolkit/modules/subprocess/test/xpcshell/test_subprocess.js
new file mode 100644
index 0000000000..b7a5d38bd1
--- /dev/null
+++ b/toolkit/modules/subprocess/test/xpcshell/test_subprocess.js
@@ -0,0 +1,869 @@
+/* eslint-disable mozilla/no-arbitrary-setTimeout */
+"use strict";
+
+const { setTimeout } = ChromeUtils.importESModule(
+  "resource://gre/modules/Timer.sys.mjs"
+);
+
+const MAX_ROUND_TRIP_TIME_MS = AppConstants.DEBUG || AppConstants.ASAN ? 18 : 9;
+const MAX_RETRIES = 5;
+
+let PYTHON;
+let PYTHON_BIN;
+let PYTHON_DIR;
+
+const TEST_SCRIPT = do_get_file("data_test_script.py").path;
+
+let read = pipe => {
+  return pipe.readUint32().then(count => {
+    return pipe.readString(count);
+  });
+};
+
+let readAll = async function(pipe) {
+  let result = [];
+  let string;
+  while ((string = await pipe.readString())) {
+    result.push(string);
+  }
+
+  return result.join("");
+};
+
+add_task(async function setup() {
+  PYTHON = await Subprocess.pathSearch(Services.env.get("PYTHON"));
+
+  PYTHON_BIN = PathUtils.filename(PYTHON);
+  PYTHON_DIR = PathUtils.parent(PYTHON);
+});
+
+add_task(async function test_subprocess_io() {
+  let proc = await Subprocess.call({
+    command: PYTHON,
+    arguments: ["-u", TEST_SCRIPT, "echo"],
+  });
+
+  Assert.throws(() => {
+    proc.stdout.read(-1);
+  }, /non-negative integer/);
+  Assert.throws(() => {
+    proc.stdout.read(1.1);
+  }, /non-negative integer/);
+
+  Assert.throws(() => {
+    proc.stdout.read(Infinity);
+  }, /non-negative integer/);
+  Assert.throws(() => {
+    proc.stdout.read(NaN);
+  }, /non-negative integer/);
+
+  Assert.throws(() => {
+    proc.stdout.readString(-1);
+  }, /non-negative integer/);
+  Assert.throws(() => {
+    proc.stdout.readString(1.1);
+  }, /non-negative integer/);
+
+  Assert.throws(() => {
+    proc.stdout.readJSON(-1);
+  }, /positive integer/);
+  Assert.throws(() => {
+    proc.stdout.readJSON(0);
+  }, /positive integer/);
+  Assert.throws(() => {
+    proc.stdout.readJSON(1.1);
+  }, /positive integer/);
+
+  const LINE1 = "I'm a leaf on the wind.\n";
+  const LINE2 = "Watch how I soar.\n";
+
+  let outputPromise = read(proc.stdout);
+
+  await new Promise(resolve => setTimeout(resolve, 100));
+
+  let [output] = await Promise.all([outputPromise, proc.stdin.write(LINE1)]);
+
+  equal(output, LINE1, "Got expected output");
+
+  // Make sure it succeeds whether the write comes before or after the
+  // read.
+  let inputPromise = proc.stdin.write(LINE2);
+
+  await new Promise(resolve => setTimeout(resolve, 100));
+
+  [output] = await Promise.all([read(proc.stdout), inputPromise]);
+
+  equal(output, LINE2, "Got expected output");
+
+  let JSON_BLOB = { foo: { bar: "baz" } };
+
+  inputPromise = proc.stdin.write(JSON.stringify(JSON_BLOB) + "\n");
+
+  output = await proc.stdout.readUint32().then(count => {
+    return proc.stdout.readJSON(count);
+  });
+
+  Assert.deepEqual(output, JSON_BLOB, "Got expected JSON output");
+
+  await proc.stdin.close();
+
+  let { exitCode } = await proc.wait();
+
+  equal(exitCode, 0, "Got expected exit code");
+});
+
+add_task(async function test_subprocess_large_io() {
+  let proc = await Subprocess.call({
+    command: PYTHON,
+    arguments: ["-u", TEST_SCRIPT, "echo"],
+  });
+
+  const LINE = "I'm a leaf on the wind.\n";
+  const BUFFER_SIZE = 4096;
+
+  // Create a message that's ~3/4 the input buffer size.
+  let msg =
+    Array(((BUFFER_SIZE * 0.75) / 16) | 0)
+      .fill("0123456789abcdef")
+      .join("") + "\n";
+
+  // This sequence of writes and reads crosses several buffer size
+  // boundaries, and causes some branches of the read buffer code to be
+  // exercised which are not exercised by other tests.
+  proc.stdin.write(msg);
+  proc.stdin.write(msg);
+  proc.stdin.write(LINE);
+
+  let output = await read(proc.stdout);
+  equal(output, msg, "Got the expected output");
+
+  output = await read(proc.stdout);
+  equal(output, msg, "Got the expected output");
+
+  output = await read(proc.stdout);
+  equal(output, LINE, "Got the expected output");
+
+  proc.stdin.close();
+
+  let { exitCode } = await proc.wait();
+
+  equal(exitCode, 0, "Got expected exit code");
+});
+
+add_task(async function test_subprocess_huge() {
+  let proc = await Subprocess.call({
+    command: PYTHON,
+    arguments: ["-u", TEST_SCRIPT, "echo"],
+  });
+
+  // This should be large enough to fill most pipe input/output buffers.
+  const MESSAGE_SIZE = 1024 * 16;
+
+  let msg =
+    Array(MESSAGE_SIZE)
+      .fill("0123456789abcdef")
+      .join("") + "\n";
+
+  proc.stdin.write(msg);
+
+  let output = await read(proc.stdout);
+  equal(output, msg, "Got the expected output");
+
+  proc.stdin.close();
+
+  let { exitCode } = await proc.wait();
+
+  equal(exitCode, 0, "Got expected exit code");
+});
+
+add_task(
+  { skip_if: () => mozinfo.ccov },
+  async function test_subprocess_round_trip_perf() {
+    let roundTripTime = Infinity;
+    for (
+      let i = 0;
+      i < MAX_RETRIES && roundTripTime > MAX_ROUND_TRIP_TIME_MS;
+      i++
+    ) {
+      let proc = await Subprocess.call({
+        command: PYTHON,
+        arguments: ["-u", TEST_SCRIPT, "echo"],
+      });
+
+      const LINE = "I'm a leaf on the wind.\n";
+
+      let now = Date.now();
+      const COUNT = 1000;
+      for (let j = 0; j < COUNT; j++) {
+        let [output] = await Promise.all([
+          read(proc.stdout),
+          proc.stdin.write(LINE),
+        ]);
+
+        // We don't want to log this for every iteration, but we still need
+        // to fail if it goes wrong.
+        if (output !== LINE) {
+          equal(output, LINE, "Got expected output");
+        }
+      }
+
+      roundTripTime = (Date.now() - now) / COUNT;
+
+      await proc.stdin.close();
+
+      let { exitCode } = await proc.wait();
+
+      equal(exitCode, 0, "Got expected exit code");
+    }
+
+    ok(
+      roundTripTime <= MAX_ROUND_TRIP_TIME_MS,
+      `Expected round trip time (${roundTripTime}ms) to be less than ${MAX_ROUND_TRIP_TIME_MS}ms`
+    );
+  }
+);
+
+add_task(async function test_subprocess_stderr_default() {
+  const LINE1 = "I'm a leaf on the wind.\n";
+  const LINE2 = "Watch how I soar.\n";
+
+  let proc = await Subprocess.call({
+    command: PYTHON,
+    arguments: ["-u", TEST_SCRIPT, "print", LINE1, LINE2],
+  });
+
+  equal(proc.stderr, undefined, "There should be no stderr pipe by default");
+
+  let stdout = await readAll(proc.stdout);
+
+  equal(stdout, LINE1, "Got the expected stdout output");
+
+  let { exitCode } = await proc.wait();
+
+  equal(exitCode, 0, "Got expected exit code");
+});
+
+add_task(async function test_subprocess_stderr_pipe() {
+  const LINE1 = "I'm a leaf on the wind.\n";
+  const LINE2 = "Watch how I soar.\n";
+
+  let proc = await Subprocess.call({
+    command: PYTHON,
+    arguments: ["-u", TEST_SCRIPT, "print", LINE1, LINE2],
+    stderr: "pipe",
+  });
+
+  let [stdout, stderr] = await Promise.all([
+    readAll(proc.stdout),
+    readAll(proc.stderr),
+  ]);
+
+  equal(stdout, LINE1, "Got the expected stdout output");
+  equal(stderr, LINE2, "Got the expected stderr output");
+
+  let { exitCode } = await proc.wait();
+
+  equal(exitCode, 0, "Got expected exit code");
+});
+
+add_task(async function test_subprocess_stderr_merged() {
+  const LINE1 = "I'm a leaf on the wind.\n";
+  const LINE2 = "Watch how I soar.\n";
+
+  let proc = await Subprocess.call({
+    command: PYTHON,
+    arguments: ["-u", TEST_SCRIPT, "print", LINE1, LINE2],
+    stderr: "stdout",
+  });
+
+  equal(proc.stderr, undefined, "There should be no stderr pipe by default");
+
+  let stdout = await readAll(proc.stdout);
+
+  equal(stdout, LINE1 + LINE2, "Got the expected merged stdout output");
+
+  let { exitCode } = await proc.wait();
+
+  equal(exitCode, 0, "Got expected exit code");
+});
+
+add_task(async function test_subprocess_read_after_exit() {
+  const LINE1 = "I'm a leaf on the wind.\n";
+  const LINE2 = "Watch how I soar.\n";
+
+  let proc = await Subprocess.call({
+    command: PYTHON,
+    arguments: ["-u", TEST_SCRIPT, "print", LINE1, LINE2],
+    stderr: "pipe",
+  });
+
+  let { exitCode } = await proc.wait();
+  equal(exitCode, 0, "Process exited with expected code");
+
+  let [stdout, stderr] = await Promise.all([
+    readAll(proc.stdout),
+    readAll(proc.stderr),
+  ]);
+
+  equal(stdout, LINE1, "Got the expected stdout output");
+  equal(stderr, LINE2, "Got the expected stderr output");
+});
+
+add_task(async function test_subprocess_lazy_close_output() {
+  let proc = await Subprocess.call({
+    command: PYTHON,
+    arguments: ["-u", TEST_SCRIPT, "echo"],
+  });
+
+  const LINE1 = "I'm a leaf on the wind.\n";
+  const LINE2 = "Watch how I soar.\n";
+
+  let writePromises = [proc.stdin.write(LINE1), proc.stdin.write(LINE2)];
+  let closedPromise = proc.stdin.close();
+
+  let output1 = await read(proc.stdout);
+  let output2 = await read(proc.stdout);
+
+  await Promise.all([...writePromises, closedPromise]);
+
+  equal(output1, LINE1, "Got expected output");
+  equal(output2, LINE2, "Got expected output");
+
+  let { exitCode } = await proc.wait();
+
+  equal(exitCode, 0, "Got expected exit code");
+});
+
+add_task(async function test_subprocess_lazy_close_input() {
+  let proc = await Subprocess.call({
+    command: PYTHON,
+    arguments: ["-u", TEST_SCRIPT, "echo"],
+  });
+
+  let readPromise = proc.stdout.readUint32();
+  let closedPromise = proc.stdout.close();
+
+  const LINE = "I'm a leaf on the wind.\n";
+
+  proc.stdin.write(LINE);
+  proc.stdin.close();
+
+  let len = await readPromise;
+  equal(len, LINE.length);
+
+  await closedPromise;
+
+  // Don't test for a successful exit here. The process may exit with a
+  // write error if we close the pipe after it's written the message
+  // size but before it's written the message.
+  await proc.wait();
+});
+
+add_task(async function test_subprocess_force_close() {
+  let proc = await Subprocess.call({
+    command: PYTHON,
+    arguments: ["-u", TEST_SCRIPT, "echo"],
+  });
+
+  let readPromise = proc.stdout.readUint32();
+  let closedPromise = proc.stdout.close(true);
+
+  await Assert.rejects(
+    readPromise,
+    function(e) {
+      equal(
+        e.errorCode,
+        Subprocess.ERROR_END_OF_FILE,
+        "Got the expected error code"
+      );
+      return /File closed/.test(e.message);
+    },
+    "Promise should be rejected when file is closed"
+  );
+
+  await closedPromise;
+  await proc.stdin.close();
+
+  let { exitCode } = await proc.wait();
+
+  equal(exitCode, 0, "Got expected exit code");
+});
+
+add_task(async function test_subprocess_eof() {
+  let proc = await Subprocess.call({
+    command: PYTHON,
+    arguments: ["-u", TEST_SCRIPT, "echo"],
+  });
+
+  let readPromise = proc.stdout.readUint32();
+
+  await proc.stdin.close();
+
+  await Assert.rejects(
+    readPromise,
+    function(e) {
+      equal(
+        e.errorCode,
+        Subprocess.ERROR_END_OF_FILE,
+        "Got the expected error code"
+      );
+      return /File closed/.test(e.message);
+    },
+    "Promise should be rejected on EOF"
+  );
+
+  let { exitCode } = await proc.wait();
+
+  equal(exitCode, 0, "Got expected exit code");
+});
+
+add_task(async function test_subprocess_invalid_json() {
+  let proc = await Subprocess.call({
+    command: PYTHON,
+    arguments: ["-u", TEST_SCRIPT, "echo"],
+  });
+
+  const LINE = "I'm a leaf on the wind.\n";
+
+  proc.stdin.write(LINE);
+  proc.stdin.close();
+
+  let count = await proc.stdout.readUint32();
+  let readPromise = proc.stdout.readJSON(count);
+
+  await Assert.rejects(
+    readPromise,
+    function(e) {
+      equal(
+        e.errorCode,
+        Subprocess.ERROR_INVALID_JSON,
+        "Got the expected error code"
+      );
+      return /SyntaxError/.test(e);
+    },
+    "Promise should be rejected on EOF"
+  );
+
+  let { exitCode } = await proc.wait();
+
+  equal(exitCode, 0, "Got expected exit code");
+});
+
+if (AppConstants.isPlatformAndVersionAtLeast("win", "6")) {
+  add_task(async function test_subprocess_inherited_descriptors() {
+    let { libc, win32 } = ChromeUtils.importESModule(
+      "resource://gre/modules/subprocess/subprocess_win.sys.mjs"
+    );
+    const { ctypes } = ChromeUtils.import("resource://gre/modules/ctypes.jsm");
+
+    let secAttr = new win32.SECURITY_ATTRIBUTES();
+    secAttr.nLength = win32.SECURITY_ATTRIBUTES.size;
+    secAttr.bInheritHandle = true;
+
+    let handles = win32.createPipe(secAttr, 0);
+
+    let proc = await Subprocess.call({
+      command: PYTHON,
+      arguments: ["-u", TEST_SCRIPT, "echo"],
+    });
+
+    // Close the output end of the pipe.
+    // Ours should be the only copy, so reads should fail after this.
+    handles[1].dispose();
+
+    let buffer = new ArrayBuffer(1);
+    let succeeded = libc.ReadFile(
+      handles[0],
+      buffer,
+      buffer.byteLength,
+      null,
+      null
+    );
+
+    ok(!succeeded, "ReadFile should fail on broken pipe");
+    equal(
+      ctypes.winLastError,
+      win32.ERROR_BROKEN_PIPE,
+      "Read should fail with ERROR_BROKEN_PIPE"
+    );
+
+    proc.stdin.close();
+
+    let { exitCode } = await proc.wait();
+
+    equal(exitCode, 0, "Got expected exit code");
+  });
+}
+
+add_task(async function test_subprocess_wait() {
+  let proc = await Subprocess.call({
+    command: PYTHON,
+    arguments: ["-u", TEST_SCRIPT, "exit", "42"],
+  });
+
+  let { exitCode } = await proc.wait();
+
+  equal(exitCode, 42, "Got expected exit code");
+});
+
+add_task(async function test_subprocess_pathSearch() {
+  let promise = Subprocess.call({
+    command: PYTHON_BIN,
+    arguments: ["-u", TEST_SCRIPT, "exit", "13"],
+    environment: {
+      PATH: PYTHON_DIR,
+    },
+  });
+
+  await Assert.rejects(
+    promise,
+    function(error) {
+      return error.errorCode == Subprocess.ERROR_BAD_EXECUTABLE;
+    },
+    "Subprocess.call should fail for a bad executable"
+  );
+});
+
+add_task(async function test_subprocess_workdir() {
+  let procDir = Services.dirsvc.get("CurWorkD", Ci.nsIFile).path;
+  let tmpDir = PathUtils.normalize(PathUtils.osTempDir);
+
+  notEqual(
+    procDir,
+    tmpDir,
+    "Current process directory must not be the current temp directory"
+  );
+
+  async function pwd(options) {
+    let proc = await Subprocess.call(
+      Object.assign(
+        {
+          command: PYTHON,
+          arguments: ["-u", TEST_SCRIPT, "pwd"],
+        },
+        options
+      )
+    );
+
+    let pwdOutput = read(proc.stdout);
+
+    let { exitCode } = await proc.wait();
+    equal(exitCode, 0, "Got expected exit code");
+
+    return pwdOutput;
+  }
+
+  let dir = await pwd({});
+  equal(
+    dir,
+    procDir,
+    "Process should normally launch in current process directory"
+  );
+
+  dir = await pwd({ workdir: tmpDir });
+  equal(
+    dir,
+    tmpDir,
+    "Process should launch in the directory specified in `workdir`"
+  );
+});
+
+add_task(async function test_subprocess_term() {
+  let proc = await Subprocess.call({
+    command: PYTHON,
+    arguments: ["-u", TEST_SCRIPT, "echo"],
+  });
+
+  // Windows does not support killing processes gracefully, so they will
+  // always exit with -9 there.
+  let retVal = AppConstants.platform == "win" ? -9 : -15;
+
+  // Kill gracefully with the default timeout of 300ms.
+  let { exitCode } = await proc.kill();
+
+  equal(exitCode, retVal, "Got expected exit code");
+
+  ({ exitCode } = await proc.wait());
+
+  equal(exitCode, retVal, "Got expected exit code");
+});
+
+add_task(async function test_subprocess_kill() {
+  let proc = await Subprocess.call({
+    command: PYTHON,
+    arguments: ["-u", TEST_SCRIPT, "echo"],
+  });
+
+  // Force kill with no gracefull termination timeout.
+  let { exitCode } = await proc.kill(0);
+
+  equal(exitCode, -9, "Got expected exit code");
+
+  ({ exitCode } = await proc.wait());
+
+  equal(exitCode, -9, "Got expected exit code");
+});
+
+add_task(async function test_subprocess_kill_timeout() {
+  let proc = await Subprocess.call({
+    command: PYTHON,
+    arguments: ["-u", TEST_SCRIPT, "ignore_sigterm"],
+  });
+
+  // Wait for the process to set up its signal handler and tell us it's
+  // ready.
+  let msg = await read(proc.stdout);
+  equal(msg, "Ready", "Process is ready");
+
+  // Kill gracefully with the default timeout of 300ms.
+  // Expect a force kill after 300ms, since the process traps SIGTERM.
+  const TIMEOUT = 300;
+  let startTime = Date.now();
+
+  let { exitCode } = await proc.kill(TIMEOUT);
+
+  // Graceful termination is not supported on Windows, so don't bother
+  // testing the timeout there.
+  if (AppConstants.platform != "win") {
+    let diff = Date.now() - startTime;
+    ok(
+      diff >= TIMEOUT,
+      `Process was killed after ${diff}ms (expected ~${TIMEOUT}ms)`
+    );
+  }
+
+  equal(exitCode, -9, "Got expected exit code");
+
+  ({ exitCode } = await proc.wait());
+
+  equal(exitCode, -9, "Got expected exit code");
+});
+
+add_task(async function test_subprocess_arguments() {
+  let args = [
+    String.raw`C:\Program Files\Company\Program.exe`,
+    String.raw`\\NETWORK SHARE\Foo Directory${"\\"}`,
+    String.raw`foo bar baz`,
+    String.raw`"foo bar baz"`,
+    String.raw`foo " bar`,
+    String.raw`Thing \" with "" "\" \\\" \\\\" quotes\\" \\`,
+  ];
+
+  let proc = await Subprocess.call({
+    command: PYTHON,
+    arguments: ["-u", TEST_SCRIPT, "print_args", ...args],
+  });
+
+  for (let [i, arg] of args.entries()) {
+    let val = await read(proc.stdout);
+    equal(val, arg, `Got correct value for args[${i}]`);
+  }
+
+  let { exitCode } = await proc.wait();
+
+  equal(exitCode, 0, "Got expected exit code");
+});
+
+add_task(async function test_subprocess_environment() {
+  let environment = {
+    FOO: "BAR",
+    EMPTY: "",
+    IGNORED: null,
+  };
+
+  // Our Windows environment can't handle launching python without
+  // PATH variables.
+  if (AppConstants.platform == "win") {
+    Object.assign(environment, {
+      PATH: Services.env.get("PATH"),
+      PATHEXT: Services.env.get("PATHEXT"),
+      SYSTEMROOT: Services.env.get("SYSTEMROOT"),
+    });
+  }
+
+  Services.env.set("BAR", "BAZ");
+
+  let proc = await Subprocess.call({
+    command: PYTHON,
+    arguments: ["-u", TEST_SCRIPT, "env", "FOO", "BAR", "EMPTY", "IGNORED"],
+    environment,
+  });
+
+  let foo = await read(proc.stdout);
+  let bar = await read(proc.stdout);
+  let empty = await read(proc.stdout);
+  let ignored = await read(proc.stdout);
+
+  equal(foo, "BAR", "Got expected $FOO value");
+  equal(bar, "!", "Got expected $BAR value");
+  equal(empty, "", "Got expected $EMPTY value");
+  equal(ignored, "!", "Got expected $IGNORED value");
+
+  let { exitCode } = await proc.wait();
+
+  equal(exitCode, 0, "Got expected exit code");
+});
+
+add_task(async function test_subprocess_environmentAppend() {
+  Services.env.set("VALUE_FROM_BASE_ENV", "untouched");
+  Services.env.set("VALUE_FROM_BASE_ENV_EMPTY", "untouched");
+  Services.env.set("VALUE_FROM_BASE_ENV_REMOVED", "untouched");
+
+  let proc = await Subprocess.call({
+    command: PYTHON,
+    arguments: [
+      "-u",
+      TEST_SCRIPT,
+      "env",
+      "VALUE_FROM_BASE_ENV",
+      "VALUE_FROM_BASE_ENV_EMPTY",
+      "VALUE_FROM_BASE_ENV_REMOVED",
+      "VALUE_APPENDED_ONCE",
+    ],
+    environmentAppend: true,
+    environment: {
+      VALUE_FROM_BASE_ENV_EMPTY: "",
+      VALUE_FROM_BASE_ENV_REMOVED: null,
+      VALUE_APPENDED_ONCE: "soon empty",
+    },
+  });
+
+  let valueFromBaseEnv = await read(proc.stdout);
+  let valueFromBaseEnvEmpty = await read(proc.stdout);
+  let valueFromBaseEnvRemoved = await read(proc.stdout);
+  let valueAppendedOnce = await read(proc.stdout);
+
+  equal(
+    valueFromBaseEnv,
+    "untouched",
+    "Got expected $VALUE_FROM_BASE_ENV value"
+  );
+  equal(
+    valueFromBaseEnvEmpty,
+    "",
+    "Got expected $VALUE_FROM_BASE_ENV_EMPTY value"
+  );
+  equal(
+    valueFromBaseEnvRemoved,
+    "!",
+    "Got expected $VALUE_FROM_BASE_ENV_REMOVED value"
+  );
+  equal(
+    valueAppendedOnce,
+    "soon empty",
+    "Got expected $VALUE_APPENDED_ONCE value"
+  );
+
+  let { exitCode } = await proc.wait();
+
+  equal(exitCode, 0, "Got expected exit code");
+
+  proc = await Subprocess.call({
+    command: PYTHON,
+    arguments: [
+      "-u",
+      TEST_SCRIPT,
+      "env",
+      "VALUE_FROM_BASE_ENV",
+      "VALUE_APPENDED_ONCE",
+    ],
+    environmentAppend: true,
+  });
+
+  valueFromBaseEnv = await read(proc.stdout);
+  valueAppendedOnce = await read(proc.stdout);
+
+  equal(
+    valueFromBaseEnv,
+    "untouched",
+    "Got expected $VALUE_FROM_BASE_ENV value"
+  );
+  equal(valueAppendedOnce, "!", "Got expected $VALUE_APPENDED_ONCE value");
+
+  ({ exitCode } = await proc.wait());
+
+  equal(exitCode, 0, "Got expected exit code");
+});
+
+if (AppConstants.platform !== "win") {
+  add_task(async function test_subprocess_nonASCII() {
+    const { libc } = ChromeUtils.importESModule(
+      "resource://gre/modules/subprocess/subprocess_unix.sys.mjs"
+    );
+
+    // Use TextDecoder rather than a string with a \xff escape, since
+    // the latter will automatically be normalized to valid UTF-8.
+    let val = new TextDecoder().decode(Uint8Array.of(1, 255));
+
+    libc.setenv(
+      "FOO",
+      Uint8Array.from(val + "\0", c => c.charCodeAt(0)),
+      1
+    );
+
+    let proc = await Subprocess.call({
+      command: PYTHON,
+      arguments: ["-u", TEST_SCRIPT, "env", "FOO"],
+    });
+
+    let foo = await read(proc.stdout);
+
+    equal(foo, val, "Got expected $FOO value");
+
+    Services.env.set("FOO", "");
+
+    let { exitCode } = await proc.wait();
+
+    equal(exitCode, 0, "Got expected exit code");
+  });
+}
+
+add_task(async function test_bad_executable() {
+  // Test with a non-executable file.
+
+  let textFile = do_get_file("data_text_file.txt").path;
+
+  let promise = Subprocess.call({
+    command: textFile,
+    arguments: [],
+  });
+
+  await Assert.rejects(
+    promise,
+    function(error) {
+      if (AppConstants.platform == "win") {
+        return /Failed to create process/.test(error.message);
+      }
+      return error.errorCode == Subprocess.ERROR_BAD_EXECUTABLE;
+    },
+    "Subprocess.call should fail for a bad executable"
+  );
+
+  // Test with a nonexistent file.
+  promise = Subprocess.call({
+    command: textFile + ".doesNotExist",
+    arguments: [],
+  });
+
+  await Assert.rejects(
+    promise,
+    function(error) {
+      return error.errorCode == Subprocess.ERROR_BAD_EXECUTABLE;
+    },
+    "Subprocess.call should fail for a bad executable"
+  );
+});
+
+add_task(async function test_cleanup() {
+  let { getSubprocessImplForTest } = ChromeUtils.importESModule(
+    "resource://gre/modules/Subprocess.sys.mjs"
+  );
+
+  let worker = getSubprocessImplForTest().Process.getWorker();
+
+  let openFiles = await worker.call("getOpenFiles", []);
+  let processes = await worker.call("getProcesses", []);
+
+  equal(openFiles.size, 0, "No remaining open files");
+  equal(processes.size, 0, "No remaining processes");
+});
diff --git a/toolkit/modules/subprocess/test/xpcshell/test_subprocess_getEnvironment.js b/toolkit/modules/subprocess/test/xpcshell/test_subprocess_getEnvironment.js
new file mode 100644
index 0000000000..cb4ea7247d
--- /dev/null
+++ b/toolkit/modules/subprocess/test/xpcshell/test_subprocess_getEnvironment.js
@@ -0,0 +1,15 @@
+"use strict";
+
+add_task(async function test_getEnvironment() {
+  Services.env.set("FOO", "BAR");
+
+  let environment = Subprocess.getEnvironment();
+
+  equal(environment.FOO, "BAR");
+  equal(environment.PATH, Services.env.get("PATH"));
+
+  Services.env.set("FOO", null);
+
+  environment = Subprocess.getEnvironment();
+  equal(environment.FOO || "", "");
+});
diff --git a/toolkit/modules/subprocess/test/xpcshell/test_subprocess_pathSearch.js b/toolkit/modules/subprocess/test/xpcshell/test_subprocess_pathSearch.js
new file mode 100644
index 0000000000..d475f66789
--- /dev/null
+++ b/toolkit/modules/subprocess/test/xpcshell/test_subprocess_pathSearch.js
@@ -0,0 +1,87 @@
+"use strict";
+
+const PYTHON = Services.env.get("PYTHON");
+
+const PYTHON_BIN = PathUtils.filename(PYTHON);
+const PYTHON_DIR = PathUtils.parent(PYTHON);
+
+const DOES_NOT_EXIST = PathUtils.join(
+  PathUtils.osTempDir,
+  "ThisPathDoesNotExist"
+);
+
+const PATH_SEP = AppConstants.platform == "win" ? ";" : ":";
+
+add_task(async function test_pathSearchAbsolute() {
+  let env = {};
+
+  let path = await Subprocess.pathSearch(PYTHON, env);
+  equal(path, PYTHON, "Full path resolves even with no PATH.");
+
+  env.PATH = "";
+  path = await Subprocess.pathSearch(PYTHON, env);
+  equal(path, PYTHON, "Full path resolves even with empty PATH.");
+
+  await Assert.rejects(
+    Subprocess.pathSearch(DOES_NOT_EXIST, env),
+    function(e) {
+      equal(
+        e.errorCode,
+        Subprocess.ERROR_BAD_EXECUTABLE,
+        "Got the expected error code"
+      );
+      return /File at path .* does not exist, or is not (executable|a normal file)/.test(
+        e.message
+      );
+    },
+    "Absolute path should throw for a nonexistent execuable"
+  );
+});
+
+add_task(async function test_pathSearchRelative() {
+  let env = {};
+
+  await Assert.rejects(
+    Subprocess.pathSearch(PYTHON_BIN, env),
+    function(e) {
+      equal(
+        e.errorCode,
+        Subprocess.ERROR_BAD_EXECUTABLE,
+        "Got the expected error code"
+      );
+      return /Executable not found:/.test(e.message);
+    },
+    "Relative path should not be found when PATH is missing"
+  );
+
+  env.PATH = [DOES_NOT_EXIST, PYTHON_DIR].join(PATH_SEP);
+
+  let path = await Subprocess.pathSearch(PYTHON_BIN, env);
+  equal(path, PYTHON, "Correct executable should be found in the path");
+});
+
+add_task(
+  {
+    skip_if: () => AppConstants.platform != "win",
+  },
+  async function test_pathSearch_PATHEXT() {
+    ok(PYTHON_BIN.endsWith(".exe"), "Python executable must end with .exe");
+
+    const python_bin = PYTHON_BIN.slice(0, -4);
+
+    let env = {
+      PATH: PYTHON_DIR,
+      PATHEXT: [".com", ".exe", ".foobar"].join(";"),
+    };
+
+    let path = await Subprocess.pathSearch(python_bin, env);
+    equal(
+      path,
+      PYTHON,
+      "Correct executable should be found in the path, with guessed extension"
+    );
+  }
+);
+// IMPORTANT: Do not add any tests beyond this point without removing
+// the `skip_if` condition from the previous task, or it will prevent
+// all succeeding tasks from running when it does not match.
diff --git a/toolkit/modules/subprocess/test/xpcshell/xpcshell.ini b/toolkit/modules/subprocess/test/xpcshell/xpcshell.ini
new file mode 100644
index 0000000000..ffed6b6de0
--- /dev/null
+++ b/toolkit/modules/subprocess/test/xpcshell/xpcshell.ini
@@ -0,0 +1,16 @@
+[DEFAULT]
+head = head.js
+firefox-appdir = browser
+skip-if = os == 'android'
+subprocess = true
+support-files =
+  data_text_file.txt
+  data_test_script.py
+
+[test_subprocess.js]
+skip-if =
+  verify
+  apple_silicon # bug 1729546
+run-sequentially = very high failure rate in parallel
+[test_subprocess_getEnvironment.js]
+[test_subprocess_pathSearch.js]