1 files changed, 157 insertions, 0 deletions
diff --git a/tools/lint/perfdocs/utils.py b/tools/lint/perfdocs/utils.py
new file mode 100644
index 0000000000..1ba7daeb52
--- /dev/null
+++ b/tools/lint/perfdocs/utils.py
@@ -0,0 +1,157 @@
+# 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 difflib
+import filecmp
+import os
+import pathlib
+
+import yaml
+from mozversioncontrol import get_repository_object
+
+from perfdocs.logger import PerfDocLogger
+
+logger = PerfDocLogger()
+
+ON_TRY = "MOZ_AUTOMATION" in os.environ
+
+
+def save_file(file_content, path, extension="rst"):
+    """
+    Saves data into a file.
+
+    :param str path: Location and name of the file being saved
+        (without an extension).
+    :param str data: Content to write into the file.
+    :param str extension: Extension to save the file as.
+    """
+    new_file = pathlib.Path("{}.{}".format(str(path), extension))
+    with new_file.open("wb") as f:
+        f.write(file_content.encode("utf-8"))
+
+
+def read_file(path, stringify=False):
+    """
+    Opens a file and returns its contents.
+
+    :param str path: Path to the file.
+    :return list: List containing the lines in the file.
+    """
+    with path.open(encoding="utf-8") as f:
+        return f.read() if stringify else f.readlines()
+
+
+def read_yaml(yaml_path):
+    """
+    Opens a YAML file and returns the contents.
+
+    :param str yaml_path: Path to the YAML to open.
+    :return dict: Dictionary containing the YAML content.
+    """
+    contents = {}
+    try:
+        with yaml_path.open(encoding="utf-8") as f:
+            contents = yaml.safe_load(f)
+    except Exception as e:
+        logger.warning(
+            "Error opening file {}: {}".format(str(yaml_path), str(e)), str(yaml_path)
+        )
+
+    return contents
+
+
+def are_dirs_equal(dir_1, dir_2):
+    """
+    Compare two directories to see if they are equal. Files in each
+    directory are assumed to be equal if their names and contents
+    are equal.
+
+    :param dir_1: First directory path
+    :param dir_2: Second directory path
+    :return: True if the directory trees are the same and False otherwise.
+    """
+
+    dirs_cmp = filecmp.dircmp(str(dir_1.resolve()), str(dir_2.resolve()))
+    if dirs_cmp.left_only or dirs_cmp.right_only or dirs_cmp.funny_files:
+        logger.log("Some files are missing or are funny.")
+        for file in dirs_cmp.left_only:
+            logger.log(f"Missing in existing docs: {file}")
+        for file in dirs_cmp.right_only:
+            logger.log(f"Missing in new docs: {file}")
+        for file in dirs_cmp.funny_files:
+            logger.log(f"The following file is funny: {file}")
+        return False
+
+    _, mismatch, errors = filecmp.cmpfiles(
+        str(dir_1.resolve()), str(dir_2.resolve()), dirs_cmp.common_files, shallow=False
+    )
+
+    if mismatch or errors:
+        logger.log(f"Found mismatches: {mismatch}")
+
+        # The root for where to save the diff will be different based on
+        # whether we are running in CI or not
+        os_root = pathlib.Path.cwd().anchor
+        diff_root = pathlib.Path(os_root, "builds", "worker")
+        if not ON_TRY:
+            diff_root = pathlib.Path(PerfDocLogger.TOP_DIR, "artifacts")
+            diff_root.mkdir(parents=True, exist_ok=True)
+
+        diff_path = pathlib.Path(diff_root, "diff.txt")
+        with diff_path.open("w", encoding="utf-8") as diff_file:
+            for entry in mismatch:
+                logger.log(f"Mismatch found on {entry}")
+
+                with pathlib.Path(dir_1, entry).open(encoding="utf-8") as f:
+                    newlines = f.readlines()
+                with pathlib.Path(dir_2, entry).open(encoding="utf-8") as f:
+                    baselines = f.readlines()
+                for line in difflib.unified_diff(
+                    baselines, newlines, fromfile="base", tofile="new"
+                ):
+                    logger.log(line)
+
+                # Here we want to add to diff.txt in a patch format, we use
+                # the basedir to make the file names/paths relative and this is
+                # different in CI vs local runs.
+                basedir = pathlib.Path(
+                    os_root, "builds", "worker", "checkouts", "gecko"
+                )
+                if not ON_TRY:
+                    basedir = diff_root
+
+                relative_path = str(pathlib.Path(dir_2, entry)).split(str(basedir))[-1]
+                patch = difflib.unified_diff(
+                    baselines, newlines, fromfile=relative_path, tofile=relative_path
+                )
+
+                write_header = True
+                for line in patch:
+                    if write_header:
+                        diff_file.write(
+                            f"diff --git a/{relative_path} b/{relative_path}\n"
+                        )
+                        write_header = False
+                    diff_file.write(line)
+
+                logger.log(f"Completed diff on {entry}")
+
+        logger.log(f"Saved diff to {diff_path}")
+
+        return False
+
+    for common_dir in dirs_cmp.common_dirs:
+        subdir_1 = pathlib.Path(dir_1, common_dir)
+        subdir_2 = pathlib.Path(dir_2, common_dir)
+        if not are_dirs_equal(subdir_1, subdir_2):
+            return False
+
+    return True
+
+
+def get_changed_files(top_dir):
+    """
+    Returns the changed files found with duplicates removed.
+    """
+    repo = get_repository_object(top_dir)
+    return list(set(repo.get_changed_files() + repo.get_outgoing_files()))