[glossary-branch-rename] Improve verify logic and update tests (#263)

Fixes #262

Author: desmondwong1215

glossary_branch_rename/test_verify.py

@@ -10,6 +10,8 @@
 from repo_smith.repo_smith import RepoSmith
 
 from .verify import (
+    NO_RENAME_EVIDENCE,
+    RESET_MESSAGE,
     verify,
     STU_LOCAL_PRESENT,
     STU_REMOTE_PRESENT,
@@ -126,3 +128,20 @@ def test_remote_old_branch_still_exists():
 
         output = test.run()
         assert_output(output, GitAutograderStatus.UNSUCCESSFUL, [STU_REMOTE_PRESENT])
+
+def test_no_rename_evidence():
+    with base_setup() as (test, rs):
+        rs.git.checkout(EXPECTED_NEW_BRANCH_NAME, branch=True)
+        rs.git.push("origin", EXPECTED_NEW_BRANCH_NAME)
+        rs.git.branch(BRANCH_TO_RENAME, delete=True)
+        rs.git.push("origin", f":{BRANCH_TO_RENAME}")
+
+        output = test.run()
+        assert_output(
+            output,
+            GitAutograderStatus.UNSUCCESSFUL,
+            [
+                NO_RENAME_EVIDENCE,
+                RESET_MESSAGE,
+            ],
+        )

glossary_branch_rename/verify.py

@@ -1,3 +1,4 @@
+import re
 from git_autograder import (
     GitAutograderOutput,
     GitAutograderExercise,
@@ -11,6 +12,32 @@
 RENAMED_LOCAL_MISSING = f"Local branch {RENAMED_BRANCH} is missing."
 STU_REMOTE_PRESENT = f"Remote branch {STU_BRANCH} still exists."
 RENAMED_REMOTE_MISSING = f"Remote branch {RENAMED_BRANCH} is missing."
+NO_RENAME_EVIDENCE = f"Local branch '{STU_BRANCH}' was not renamed to '{RENAMED_BRANCH}'!"
+RESET_MESSAGE = 'If needed, reset the repository using "gitmastery progress reset" and start again.'
+
+
+def branch_has_rename_evidence(
+    exercise: GitAutograderExercise, new_branch: str, old_branch: str
+) -> bool:
+    """Performs a DFS on the branch renames starting with STU till S-to-Z.
+
+    This is necessary since the renames could be performed in parts:
+
+    STU -> S-to-U -> S-to-Z
+    """
+    branch = exercise.repo.branches.branch(new_branch)
+
+    rename_regex = re.compile("^renamed refs/heads/(.+) to refs/heads/(.+)$")
+    for entry in branch.reflog[::-1]:
+        match_group = rename_regex.match(entry.message)
+        if match_group is None:
+            continue
+        original = match_group.group(1)
+        new = match_group.group(2)
+        if original == old_branch:
+            old_branch = new
+
+    return old_branch == new_branch
 
 
 def verify(exercise: GitAutograderExercise) -> GitAutograderOutput:
@@ -42,6 +69,9 @@ def verify(exercise: GitAutograderExercise) -> GitAutograderOutput:
 
     if comments:
         raise exercise.wrong_answer(comments)
+    
+    if not branch_has_rename_evidence(exercise, RENAMED_BRANCH, STU_BRANCH):
+        raise exercise.wrong_answer([NO_RENAME_EVIDENCE, RESET_MESSAGE])
 
     return exercise.to_output(
         ["Nice work renaming the branch locally and on the remote!"],