Implement backouts handling for commits with git reverts.

config/dev/sync.ini

@@ -57,4 +57,5 @@ listener.interval = 60
 
 [lando]
 api_token=%SECRET%
+api_url = https://lando.moz.tools/api
 user_email=wptsync@mozilla.com

sync/commit.py

@@ -11,6 +11,7 @@
 from . import log
 from .env import Environment
 from .errors import AbortError
+from .lando import git2hg
 from .repos import cinnabar, cinnabar_map, pygit2_get
 
 from typing import Dict
@@ -544,8 +545,16 @@ def has_wpt_changes(self) -> bool:
 
     @property
     def is_backout(self) -> bool:
+        return self.is_hg_backout or self.is_git_revert
+
+    @property
+    def is_hg_backout(self) -> bool:
         return commitparser.is_backout(self.msg)
 
+    @property
+    def is_git_revert(self) -> bool:
+        return commitparser.parse_reverts(self.msg) is not None
+
     @property
     def is_downstream(self) -> bool:
         from . import downstream
@@ -563,7 +572,13 @@ def commits_backed_out(self) -> tuple[list[GeckoCommit], set[int]]:
         commits: list[GeckoCommit] = []
         bugs: list[int] = []
         if self.is_backout:
-            nodes_bugs = commitparser.parse_backouts(self.msg)
+            nodes_bugs = None
+
+            if self.is_hg_backout:
+                nodes_bugs = commitparser.parse_backouts(self.msg)
+            elif self.is_git_revert:
+                nodes_bugs = commitparser.parse_reverts(self.msg)
+
             if nodes_bugs is None:
                 # We think this a backout, but have no idea what it backs out
                 # it's not clear how to handle that case so for now we pretend it isn't
@@ -573,7 +588,11 @@ def commits_backed_out(self) -> tuple[list[GeckoCommit], set[int]]:
             nodes, bugs = nodes_bugs
             # Assuming that all commits are listed.
             for node in nodes:
-                git_sha = cinnabar(self.repo).hg2git(node.decode("ascii"))
+                hg_revision = node.decode("ascii")
+                if self.is_git_revert:
+                    # Convert original git hash to mercurial
+                    hg_revision = git2hg(hg_revision)
+                git_sha = cinnabar(self.repo).hg2git(hg_revision)
                 commits.append(GeckoCommit(self.repo, git_sha))
 
         return commits, set(bugs)

sync/lando.py

@@ -0,0 +1,21 @@
+import json
+import urllib.request
+
+from .env import Environment
+from . import log
+
+env = Environment()
+
+logger = log.get_logger(__name__)
+
+
+def git2hg(git_hash: str) -> str:
+    response = urllib.request.urlopen(
+        env.config["lando"]["api_url"] + "/git2hg/firefox/" + git_hash
+    )  # nosec B310
+    data = response.read()
+    map = json.loads(data.decode("utf-8"))
+    assert isinstance(map, dict)
+    assert isinstance(map["hg_hash"], str)
+
+    return map["hg_hash"]

sync_prod.ini

@@ -107,4 +107,5 @@ repo.url = https://github.com/web-platform-tests/wpt-metadata
 
 [lando]
 api_token=%SECRET%
+api_url = https://lando.moz.tools/api
 user_email=wptsync@mozilla.com

test/config/sync.ini

@@ -63,4 +63,5 @@ listener.interval = 60
 
 [lando]
 api_token="%SECRET%"
+api_url = https://lando.moz.tools/api
 user_email="wptsync@mozilla.com"

test/conftest.py

@@ -1,5 +1,6 @@
 import copy
 import glob
+import hashlib
 import io
 import json
 import os
@@ -383,6 +384,20 @@ def inner(revs, bugs, message=None, bookmarks="mozilla/autoland"):
     return inner
 
 
+@pytest.fixture
+def upstream_gecko_revert(env, hg_gecko_upstream):
+    def inner(message, rev, bookmarks="mozilla/autoland"):
+        # Git hash has to be converted to hg hash with API.
+        # Since we going to mock this API call, this git hash
+        # can have a random value that just looks like git hash.
+        random_hash = hashlib.sha1(os.urandom(20)).hexdigest()
+        commit_message = f"""Revert \"{message}\"\nThis reverts commit {random_hash}.""".encode()
+        hg_gecko_upstream.backout("--no-commit", rev)
+        return hg_commit(hg_gecko_upstream, commit_message, bookmarks)
+
+    return inner
+
+
 @pytest.fixture
 def gecko_worktree(env, git_gecko):
     path = os.path.join(env.config["root"], env.config["paths"]["worktrees"], "gecko", "autoland")

test/test_upstream.py

@@ -1,3 +1,5 @@
+from unittest.mock import patch
+
 from sync import commit as sync_commit, upstream
 from sync.gitutils import update_repositories
 from sync.lock import SyncLock
@@ -84,6 +86,44 @@ def test_create_pr_backout(git_gecko, git_wpt, upstream_gecko_commit, upstream_g
     assert backout_commit.upstream_sync(git_gecko, git_wpt) == sync
 
 
+def test_create_pr_revert(git_gecko, git_wpt, upstream_gecko_commit, upstream_gecko_revert):
+    bug = 1234
+    test_changes = {"README": b"Change README\n"}
+    message = f"Bug {bug} - Change README"
+    rev = upstream_gecko_commit(test_changes=test_changes, bug=bug, message=message.encode())
+
+    update_repositories(git_gecko, git_wpt, wait_gecko_commit=rev)
+    upstream.gecko_push(git_gecko, git_wpt, "autoland", rev, raise_on_error=True)
+
+    syncs = upstream.UpstreamSync.for_bug(git_gecko, git_wpt, bug)
+    assert list(syncs.keys()) == ["open"]
+    assert len(syncs["open"]) == 1
+    sync = syncs["open"].pop()
+    assert sync.bug == 1234
+    assert sync.status == "open"
+    assert len(sync.gecko_commits) == 1
+    assert len(sync.wpt_commits) == 1
+    assert sync.pr
+
+    backout_rev = upstream_gecko_revert(message, rev)
+
+    update_repositories(git_gecko, git_wpt, wait_gecko_commit=backout_rev)
+    with patch("sync.commit.git2hg", return_value=rev):
+        upstream.gecko_push(git_gecko, git_wpt, "autoland", backout_rev, raise_on_error=True)
+    syncs = upstream.UpstreamSync.for_bug(git_gecko, git_wpt, bug)
+    assert list(syncs.keys()) == ["incomplete"]
+    assert len(syncs["incomplete"]) == 1
+    sync = syncs["incomplete"].pop()
+    assert sync.bug == 1234
+    with patch("sync.commit.git2hg", return_value=rev):
+        assert len(sync.gecko_commits) == 0
+    assert len(sync.wpt_commits) == 1
+    assert len(sync.upstreamed_gecko_commits) == 1
+    assert sync.status == "incomplete"
+    backout_commit = sync_commit.GeckoCommit(git_gecko, cinnabar(git_gecko).hg2git(rev))
+    assert backout_commit.upstream_sync(git_gecko, git_wpt) == sync
+
+
 def test_create_pr_backout_reland(
     git_gecko, git_wpt, upstream_gecko_commit, upstream_gecko_backout
 ):