write tests for tag_tracker

packages/opal-common/opal_common/git/tests/conftest.py

@@ -73,6 +73,15 @@ def create_rename_file_commit(
         repo.index.move([filename, new_filename])
         repo.index.commit(commit_msg, author=author)
 
+    @staticmethod
+    def create_new_tag(repo: Repo, tag_name: str):
+        repo.create_tag(tag_name)
+
+    @staticmethod
+    def update_tag_to_head(repo: Repo, tag_name: str):
+        repo.delete_tag(tag_name)
+        repo.create_tag(tag_name)
+
 
 @pytest.fixture
 def helpers() -> Helpers:
@@ -140,6 +149,9 @@ def local_repo(tmp_path, helpers: Helpers) -> Repo:
 
     # create a "delete" commit
     helpers.create_delete_file_commit(repo, root / "deleted.rego")
+
+    # create a test tag
+    helpers.create_new_tag(repo, "test_tag")
     return repo
 
 

packages/opal-common/opal_common/git/tests/tag_tracker_test.py

@@ -0,0 +1,78 @@
+import os
+import sys
+
+import pytest
+
+# Add root opal dir to use local src as package for tests (i.e, no need for python -m pytest)
+root_dir = os.path.abspath(
+    os.path.join(
+        os.path.dirname(__file__),
+        os.path.pardir,
+        os.path.pardir,
+        os.path.pardir,
+    )
+)
+sys.path.append(root_dir)
+
+from pathlib import Path
+
+from git import Repo
+from git.objects.commit import Commit
+from opal_common.git.tag_tracker import TagTracker
+from opal_common.git.exceptions import GitFailed
+
+
+def test_pull_with_no_changes(local_repo_clone: Repo):
+    """Test pulling when there are no changes on the remote repo."""
+    repo: Repo = local_repo_clone  # local repo, cloned from another local repo
+    tracker = TagTracker(repo=repo, tag_name="test_tag")
+    latest_commit: Commit = repo.head.commit
+    assert latest_commit == tracker.latest_commit == tracker.prev_commit
+    has_changes, prev, latest = tracker.pull()  # pulls from origin
+    assert has_changes == False
+    assert latest_commit == prev == latest
+
+
+def test_pull_with_new_commits(
+    local_repo: Repo,
+    local_repo_clone: Repo,
+    helpers,
+):
+    """Test pulling when there are changes (new commits) on the remote repo."""
+    remote_repo: Repo = (
+        local_repo  # local repo, the 'origin' remote of 'local_repo_clone'
+    )
+    repo: Repo = local_repo_clone  # local repo, cloned from 'local_repo'
+
+    tracker = TagTracker(repo=repo, tag_name="test_tag")
+    most_recent_commit_before_pull: Commit = repo.head.commit
+
+    assert (
+        most_recent_commit_before_pull == tracker.latest_commit == tracker.prev_commit
+    )
+
+    # create new file commit on the remote repo
+    helpers.create_new_file_commit(
+        remote_repo, Path(remote_repo.working_tree_dir) / "2.txt"
+    )
+
+    helpers.update_tag_to_head(remote_repo, "test_tag")
+
+    # now the remote repo tag is pointing at a different commit
+    assert remote_repo.tags.__getattr__("test_tag").commit != repo.head.commit
+    # and our tag tracker does not know it yet
+    assert remote_repo.tags.__getattr__("test_tag").commit != tracker.latest_commit
+
+    has_changes, prev, latest = tracker.pull()  # pulls from origin
+    assert has_changes == True
+    assert prev != latest
+    assert most_recent_commit_before_pull == prev
+    assert (
+        remote_repo.tags.__getattr__("test_tag").commit == repo.tags.__getattr__("test_tag").commit == latest == tracker.latest_commit
+    )
+
+
+def test_tracked_branch_does_not_exist(local_repo: Repo):
+    """Test that tag tracker throws when tag does not exist."""
+    with pytest.raises(GitFailed):
+        tracker = TagTracker(local_repo, tag_name="no_such_tag")