feat(releases): Clear the commits associated to a release (#28831)

Objective:
This PR creates a new clear_commits method on the Release model to delete the associated ReleaseCommits and ReleaseHeadCommit and reset the commit related metadata for the release. We will not delete the rows in the Commit table because they may be used for another release.

src/sentry/api/endpoints/organization_release_details.py

@@ -453,14 +453,21 @@ def put(self, request, organization, version):
 
             refs = result.get("refs")
             if not refs:
-                refs = [
-                    {
-                        "repository": r["repository"],
-                        "previousCommit": r.get("previousId"),
-                        "commit": r["currentId"],
-                    }
-                    for r in result.get("headCommits", [])
-                ]
+                # Handle legacy
+                if result.get("headCommits", []):
+                    refs = [
+                        {
+                            "repository": r["repository"],
+                            "previousCommit": r.get("previousId"),
+                            "commit": r["currentId"],
+                        }
+                        for r in result.get("headCommits", [])
+                    ]
+                # Clear commits in release
+                else:
+                    if result.get("refs") == []:
+                        release.clear_commits()
+
             scope.set_tag("has_refs", bool(refs))
             if refs:
                 if not request.user.is_authenticated:

src/sentry/models/release.py

@@ -1079,6 +1079,25 @@ def count_artifacts(self):
         counts = get_artifact_counts([self.id])
         return counts.get(self.id, 0)
 
+    def clear_commits(self):
+        """
+        Delete all release-specific commit data associated to this release. We will not delete the Commit model values because other releases may use these commits.
+        """
+        with sentry_sdk.start_span(op="clear_commits"):
+            from sentry.models import ReleaseCommit, ReleaseHeadCommit
+
+            ReleaseHeadCommit.objects.get(
+                organization_id=self.organization_id, release=self
+            ).delete()
+            ReleaseCommit.objects.filter(
+                organization_id=self.organization_id, release=self
+            ).delete()
+
+            self.authors = []
+            self.commit_count = 0
+            self.last_commit_id = None
+            self.save()
+
 
 def get_artifact_counts(release_ids: List[int]) -> Mapping[int, int]:
     """Get artifact count grouped by IDs"""

tests/sentry/models/test_release.py

@@ -1204,3 +1204,77 @@ def test_follows_semver_check_when_project_only_has_two_releases(self):
             )
             is False
         )
+
+
+class ClearCommitsTestCase(TestCase):
+    def test_simple(self):
+        org = self.create_organization()
+        project = self.create_project(organization=org, name="foo")
+        group = self.create_group(project=project)
+
+        repo = Repository.objects.create(organization_id=org.id, name="test/repo")
+
+        author = CommitAuthor.objects.create(
+            name="foo bar baz", email="foo@example.com", organization_id=org.id
+        )
+
+        author2 = CommitAuthor.objects.create(
+            name="foo bar boo", email="baroo@example.com", organization_id=org.id
+        )
+
+        commit = Commit.objects.create(
+            organization_id=org.id,
+            repository_id=repo.id,
+            author=author,
+            date_added="2019-03-01 12:00:00",
+            message="fixes %s" % (group.qualified_short_id),
+            key="alksdflskdfjsldkfajsflkslk",
+        )
+        commit2 = Commit.objects.create(
+            organization_id=org.id,
+            repository_id=repo.id,
+            author=author2,
+            date_added="2019-03-01 12:02:00",
+            message="i fixed something",
+            key="lskfslknsdkcsnlkdflksfdkls",
+        )
+
+        release = Release.objects.create(version="abcdabc", organization=org)
+        release.add_project(project)
+        release.set_commits(
+            [
+                {"id": commit.key, "repository": repo.name},
+                {"id": commit2.key, "repository": repo.name},
+            ]
+        )
+        # Confirm setup works
+        assert ReleaseCommit.objects.filter(commit=commit, release=release).exists()
+        assert ReleaseCommit.objects.filter(commit=commit2, release=release).exists()
+
+        assert release.commit_count == 2
+        assert release.authors == [str(author.id), str(author2.id)]
+        assert release.last_commit_id == commit.id
+
+        assert ReleaseHeadCommit.objects.filter(
+            release_id=release.id, commit_id=commit.id, repository_id=repo.id
+        ).exists()
+
+        # Now clear the release;
+        release.clear_commits()
+        assert not ReleaseCommit.objects.filter(commit=commit, release=release).exists()
+        assert not ReleaseCommit.objects.filter(commit=commit2, release=release).exists()
+        assert not ReleaseHeadCommit.objects.filter(
+            release_id=release.id, commit_id=commit.id, repository_id=repo.id
+        ).exists()
+
+        assert release.commit_count == 0
+        assert release.authors == []
+        assert not release.last_commit_id
+
+        # Commits should still exist
+        assert Commit.objects.filter(
+            id=commit.id, organization_id=org.id, repository_id=repo.id
+        ).exists()
+        assert Commit.objects.filter(
+            id=commit2.id, organization_id=org.id, repository_id=repo.id
+        ).exists()