[GHF] Allow reverts from pytorch-auto-revert app (#164911)

This is a bit weird, but author_login is not a unique field, but author_url is.

Explicitly allow https://github.com/apps/pytorch-auto-revert to issue revert commands

Update mocks by running
```
sed -i -e s/8e262b0495bd934d39dda198d4c09144311c5ddd6cca6a227194bd48dbfe7201/47860a8f57a214a426d1150c29893cbc2aa49507f12b731483b1a1254bca3428/ gql_mocks.json
```

Test plan: Run
```python
from trymerge import GitHubPR
pr=GitHubPR("pytorch", "pytorch", 164660)
print(pr.get_last_comment().author_url, pr.get_comment_by_id(3375785595).author_url)
```
that should produce
```
https://github.com/pytorch-auto-revert https://github.com/apps/pytorch-auto-revert
```
Plus added a regression test that checks two particular comments for revert validity

`pytorch-auto-revert` user is my alter ego :)
Pull Request resolved: https://github.com/pytorch/pytorch/pull/164911
Approved by: https://github.com/jeanschmidt

.github/scripts/github_utils.py

@@ -18,6 +18,7 @@ class GitHubComment:
     body_text: str
     created_at: str
     author_login: str
+    author_url: Optional[str]
     author_association: str
     editor_login: Optional[str]
     database_id: int

.github/scripts/test_check_labels.py

@@ -38,6 +38,7 @@ def mock_get_comments() -> list[GitHubComment]:
             body_text="mock_body_text",
             created_at="",
             author_login="",
+            author_url=None,
             author_association="",
             editor_login=None,
             database_id=1,
@@ -48,6 +49,7 @@ def mock_get_comments() -> list[GitHubComment]:
             body_text=" #" + LABEL_ERR_MSG_TITLE.replace("`", ""),
             created_at="",
             author_login=BOT_AUTHORS[1],
+            author_url=None,
             author_association="",
             editor_login=None,
             database_id=2,

.github/scripts/test_trymerge.py

@@ -32,6 +32,7 @@ from trymerge import (
     main as trymerge_main,
     MandatoryChecksMissingError,
     MergeRule,
+    PostCommentError,
     RE_GHSTACK_DESC,
     read_merge_rules,
     remove_job_name_suffix,
@@ -588,6 +589,23 @@ class TestTryMerge(TestCase):
             self.assertEqual(mock_merge_base, pr.get_merge_base())
             mocked_gh_fetch_merge_base.assert_called_once()
 
+    def test_app_can_revert(self, *args: Any) -> None:
+        pr = GitHubPR("pytorch", "pytorch", 164660)
+        repo = DummyGitRepo()
+        app_comment_id, impostor_comment_id = 3375785595, 3377647892
+        # Check that app can revert
+        self.assertIsNotNone(validate_revert(repo, pr, comment_id=app_comment_id))
+        # But impostor can not
+        self.assertRaises(
+            PostCommentError,
+            lambda: validate_revert(repo, pr, comment_id=impostor_comment_id),
+        )
+        # Despite it's name being the name of the bot
+        self.assertEqual(
+            pr.get_comment_by_id(impostor_comment_id).author_login,
+            "pytorch-auto-revert",
+        )
+
 
 @mock.patch("trymerge.gh_graphql", side_effect=mocked_gh_graphql)
 @mock.patch("trymerge.gh_fetch_merge_base", return_value="")

.github/scripts/trymerge.py

@@ -234,6 +234,7 @@ query ($owner: String!, $name: String!, $number: Int!) {
           createdAt
           author {
             login
+            url
           }
           authorAssociation
           editor {
@@ -1093,6 +1094,7 @@ class GitHubPR:
             body_text=node["bodyText"],
             created_at=node["createdAt"] if "createdAt" in node else "",
             author_login=node["author"]["login"],
+            author_url=node["author"].get("url", None),
             author_association=node["authorAssociation"],
             editor_login=editor["login"] if editor else None,
             database_id=node["databaseId"],
@@ -2029,6 +2031,11 @@ def validate_revert(
     # For some reason, one can not be a member of private repo, only CONTRIBUTOR
     if pr.is_base_repo_private():
         allowed_reverters.append("CONTRIBUTOR")
+    # Special case the pytorch-auto-revert app, whose does not have association
+    # But should be able to issue revert command
+    if comment.author_url == "https://github.com/apps/pytorch-auto-revert":
+        allowed_reverters.append("NONE")
+
     if author_association not in allowed_reverters:
         raise PostCommentError(
             f"Will not revert as @{author_login} is not one of "