fix: update update_commit to support tokenless v3

we used to prepend the slug to the branch name when detecting that the
commit is on a fork, but now we want the format of a forked branch to be
<username>:<branch name> so we try to extract the username from the
slug of the head of the PR that the commit is on

Signed-off-by: joseph-sentry <joseph.sawaya@sentry.io>

services/repository.py

@@ -253,9 +253,19 @@ async def update_commit_from_provider_info(repository_service, commit):
             # so we append the branch name with the fork slug
             branch_name = commit_updates["head"]["branch"]
             # TODO: 'slug' is in a `.get` because currently only GitHub returns that info
+
             if commit_updates["head"].get("slug") != commit_updates["base"].get("slug"):
-                branch_name = commit_updates["head"]["slug"] + ":" + branch_name
+                # get rid of repo name in head.slug
+                try:
+                    username = commit_updates["head"]["slug"].split("/")[0]
+                    branch_name = username + ":" + branch_name
+                except:
+                    log.error(
+                        "Error updating branch name for commit originating from fork",
+                        extra=dict(repoid=commit.repoid, commit=commit.commitid),
+                    )
             commit.branch = branch_name
+
             commit.merged = False
         else:
             possible_branches = await repository_service.get_best_effort_branches(

services/tests/test_repository_service.py

@@ -960,6 +960,7 @@ async def test_update_commit_from_provider_info_pull_from_fork(
             _report_json=None,
             repository=possible_parent_commit.repository,
         )
+        commit.branch = "main"
         dbsession.add(possible_parent_commit)
         dbsession.add(commit)
         dbsession.flush()
@@ -993,7 +994,7 @@ async def test_update_commit_from_provider_info_pull_from_fork(
         assert commit.pullid == 1
         assert commit.totals is None
         assert commit.report_json == {}
-        assert commit.branch == f"some-guy/{commit.repository.name}:main"
+        assert commit.branch == "main"
         assert commit.parent_commit_id == possible_parent_commit.commitid
         assert commit.state == "complete"
         assert commit.author is not None