Bug 1819101 - Add JSON summary to taskgraph diff output with warnings support, r=ahal

Differential Revision: https://phabricator.services.mozilla.com/D171111

taskcluster/ci/source-test/taskgraph.yml

@@ -29,7 +29,8 @@ diff:
         cwd: '{checkout}'
         command: >-
             mkdir -p /builds/worker/artifacts/diffs &&
-            ./mach taskgraph target --fast -p "taskcluster/test/params" -o "/builds/worker/artifacts/diffs/diff.txt" --diff {base_rev}
+            ./mach taskgraph target --fast -p "taskcluster/test/params" -o "/builds/worker/artifacts/diffs/diff.txt" --diff {base_rev} &&
+            python taskcluster/scripts/misc/summarize-tgdiff.py /builds/worker/artifacts/diffs/ 20
     when:
         files-changed:
             - 'taskcluster/ci/**'

taskcluster/scripts/misc/summarize-tgdiff.py

@@ -0,0 +1,45 @@
+# 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 argparse
+import json
+import pathlib
+
+
+def run():
+
+    parser = argparse.ArgumentParser(
+        description="Classify output of taskgraph for CI analsyis"
+    )
+    parser.add_argument(
+        "path",
+        type=pathlib.Path,
+        help="Folder containing all the TXT files from taskgraph target.",
+    )
+    parser.add_argument(
+        "threshold",
+        type=int,
+        help="Minimum number of lines to trigger a warning on taskgraph output.",
+    )
+    args = parser.parse_args()
+
+    out = {"files": {}, "status": "OK", "threshold": args.threshold}
+    for path in args.path.glob("*.txt"):
+
+        with path.open() as f:
+            nb = len(list(filter(None, f.readlines())))
+
+        out["files"][path.stem] = {
+            "nb": nb,
+            "status": "WARNING" if nb >= args.threshold else "OK",
+        }
+
+        if nb >= args.threshold:
+            out["status"] = "WARNING"
+
+    (args.path / "summary.json").write_text(json.dumps(out, sort_keys=True, indent=4))
+
+
+if __name__ == "__main__":
+    run()