[mix-messy-graph] Fix merge commit check

Author: woojiahao

mix_messy_graph/tests/specs/non_squash_merge_used_2.yml

@@ -0,0 +1,47 @@
+initialization:
+  steps:
+    - type: commit
+      empty: true
+      message: Add features.md
+      id: start
+    - type: commit
+      empty: true
+      message: Mention feature for creating books
+    - type: tag
+      tag-name: v1.0
+    - type: commit
+      empty: true
+      message: Fix phrasing of heading
+
+    - type: branch
+      branch-name: feature-search
+    - type: commit
+      empty: true
+      message: Feature search
+    - type: checkout
+      branch-name: main
+    - type: merge
+      branch-name: feature-search
+      no-ff: true
+
+    - type: commit
+      empty: true
+      message: Add the delete feature
+
+    - type: new-file
+      filename: features.md
+      contents: |
+        # Features
+
+        ## Create Book
+
+        Allows creating one book at a time.
+
+        ## Searching for Books
+
+        Allows searching for books by keywords.
+        Works only for book titles.
+
+        ## Deleting Books
+
+        Allows deleting books.

mix_messy_graph/tests/test_verify.py

@@ -1,8 +1,8 @@
 from git_autograder import GitAutograderStatus, GitAutograderTestLoader, assert_output
 
 from ..verify import (
-    FEATURE_SEARCH_BRANCH_STILL_EXISTS,
     FEATURE_DELETE_BRANCH_STILL_EXISTS,
+    FEATURE_SEARCH_BRANCH_STILL_EXISTS,
     FEATURES_FILE_CONTENT_INVALID,
     LIST_BRANCH_STILL_EXISTS,
     MISMATCH_COMMIT_MESSAGE,
@@ -22,7 +22,25 @@ def test_base():
 
 def test_non_squash_merge_used():
     with loader.load("specs/non_squash_merge_used.yml") as output:
-        assert_output(output, GitAutograderStatus.UNSUCCESSFUL, [SQUASH_NOT_USED])
+        # This would fail because the squash merge changes the commit messages and the contents
+        assert_output(
+            output,
+            GitAutograderStatus.UNSUCCESSFUL,
+            [
+                MISMATCH_COMMIT_MESSAGE.format(
+                    expected="Add the search feature", given="Feature search"
+                )
+            ],
+        )
+
+
+def test_non_squash_merge_used_2():
+    with loader.load("specs/non_squash_merge_used_2.yml") as output:
+        assert_output(
+            output,
+            GitAutograderStatus.UNSUCCESSFUL,
+            [SQUASH_NOT_USED],
+        )
 
 
 def test_wrong_commit_message():

mix_messy_graph/verify.py

@@ -55,10 +55,7 @@ def ensure_str(val) -> str:
 def verify(exercise: GitAutograderExercise) -> GitAutograderOutput:
     main_branch = exercise.repo.branches.branch("main")
     merge_commits = [c for c in main_branch.commits if len(c.parents) > 1]
-    merge_reflogs = [e for e in main_branch.reflog if "merge" in e.action]
-    # We expect 1 merge reflog entry because of the setup step which merges the branch,
-    # but no other merges should be present
-    if merge_commits or len(merge_reflogs) > 1:
+    if merge_commits:
         raise exercise.wrong_answer([SQUASH_NOT_USED])
 
     commit_messages = [ensure_str(c.commit.message) for c in main_branch.commits][::-1]