repo: pass default_branch to SCM if set (bug 1951843)

src/lando/main/models/repo.py

@@ -154,7 +154,11 @@ def scm(self) -> AbstractSCM:
         """Return the SCM implementation associated with this Repository"""
         if not self._scm:
             if impl := SCM_IMPLEMENTATIONS.get(self.scm_type):
-                self._scm = impl(self.path)
+                kwargs = {}
+                if self.default_branch:
+                    kwargs["default_branch"] = self.default_branch
+
+                self._scm = impl(self.path, **kwargs)
             else:
                 raise Exception(f"Repository type not supported: {self.scm_type}")
         return self._scm

src/lando/main/scm/abstract_scm.py

@@ -12,7 +12,7 @@ class AbstractSCM:
     # The path to the repository.
     path: str
 
-    def __init__(self, path: str):
+    def __init__(self, path: str, **kwargs):
         self.path = path
 
     def __str__(self):

src/lando/main/scm/git.py

@@ -59,7 +59,7 @@ class GitSCM(AbstractSCM):
 
     default_branch: str
 
-    def __init__(self, path: str, default_branch: str = "main"):
+    def __init__(self, path: str, default_branch: str = "main", **kwargs):
         self.default_branch = default_branch
         super().__init__(path)
 

src/lando/main/scm/hg.py

@@ -162,7 +162,7 @@ class HgSCM(AbstractSCM):
 
     hg_repo: hglib.client.hgclient
 
-    def __init__(self, path: str, config: Optional[dict] = None):
+    def __init__(self, path: str, config: Optional[dict] = None, **kwargs):
         self.config = copy.copy(self.DEFAULT_CONFIGS)
 
         # Somewhere to store patch headers for testing.

src/lando/main/tests/test_models.py

@@ -156,3 +156,14 @@ def test__models__Revision__metadata():
     assert r.commit_message == commit_message
     assert r.timestamp == timestamp
     assert r.diff == DIFF_ONLY
+
+
+@pytest.mark.parametrize(
+    "branch,expected_branch", [(None, "main"), ("non-default", "non-default")]
+)
+def test_repo_default_branch_to_scm(branch: str, expected_branch: str):
+    repo_path = "some_repo"
+    repo = Repo(pull_path=repo_path, scm_type=SCM_TYPE_GIT, default_branch=branch)
+
+    # repo.scm here is a GitSCM
+    assert repo.scm.default_branch == expected_branch