Look for tree SHA in all branches

tagbot/action/repo.py

@@ -97,15 +97,32 @@ def _create_release_branch_pr(self, version: str, branch: str) -> None:
             base=self._repo.default_branch,
         )
 
-    def _commit_sha_of_tree(self, tree: str) -> Optional[str]:
-        """Look up the commit SHA of a tree with the given SHA."""
-        since = datetime.now() - self._lookback
-        for commit in self._repo.get_commits(since=since):
+    def _commit_sha_of_tree_from_branch(
+        self, branch: str, tree: str, since: datetime
+    ) -> Optional[str]:
+        """Look up the commit SHA of a tree with the given SHA on one branch."""
+        for commit in self._repo.get_commits(sha=branch, since=since):
             if commit.commit.tree.sha == tree:
                 # TODO: Remove the string conversion when PyGithub is typed.
                 return str(commit.sha)
         return None
 
+    def _commit_sha_of_tree(self, tree: str) -> Optional[str]:
+        """Look up the commit SHA of a tree with the given SHA."""
+        since = datetime.now() - self._lookback
+        sha = self._commit_sha_of_tree_from_branch(
+            self._repo.default_branch, tree, since
+        )
+        if sha:
+            return sha
+        for branch in self._repo.get_branches():
+            if branch.name == self._repo.default_branch:
+                continue
+            sha = self._commit_sha_of_tree_from_branch(branch.name, tree, since)
+            if sha:
+                return sha
+        return None
+
     def _commit_sha_of_tag(self, version: str) -> Optional[str]:
         """Look up the commit SHA of a given tag."""
         try:

test/action/test_repo.py

@@ -81,16 +81,31 @@ def test_create_release_branch_pr():
     )
 
 
-def test_commit_sha_of_tree():
+def test_commit_sha_of_tree_from_branch():
     r = _repo()
+    since = datetime.now()
     r._repo.get_commits = Mock(return_value=[Mock(sha="abc"), Mock(sha="sha")])
     r._repo.get_commits.return_value[1].commit.tree.sha = "tree"
-    assert r._commit_sha_of_tree("tree") == "sha"
+    assert r._commit_sha_of_tree_from_branch("master", "tree", since) == "sha"
+    r._repo.get_commits.assert_called_with(sha="master", since=since)
     r._repo.get_commits.return_value.pop()
-    assert r._commit_sha_of_tree("tree") is None
-    since = r._repo.get_commits.mock_calls[0].kwargs["since"]
-    expected = datetime.now() - timedelta(days=3, hours=1)
-    assert expected - since < timedelta(seconds=5)
+    assert r._commit_sha_of_tree_from_branch("master", "tree", since) is None
+
+
+def test_commit_sha_of_tree():
+    r = _repo()
+    now = datetime.now()
+    r._repo = Mock(default_branch="master",)
+    branches = r._repo.get_branches.return_value = [Mock(), Mock()]
+    branches[0].name = "foo"
+    branches[1].name = "master"
+    r._lookback = Mock(__rsub__=lambda x, y: now)
+    r._commit_sha_of_tree_from_branch = Mock(side_effect=["sha1", None, "sha2"])
+    assert r._commit_sha_of_tree("tree") == "sha1"
+    r._repo.get_branches.assert_not_called()
+    r._commit_sha_of_tree_from_branch.assert_called_once_with("master", "tree", now)
+    assert r._commit_sha_of_tree("tree") == "sha2"
+    r._commit_sha_of_tree_from_branch.assert_called_with("foo", "tree", now)
 
 
 def test_commit_sha_of_tag():