Fix blame highlighting and strip common prefix from file tree

- Strip common top-level directories from file tree paths for cleaner display
- Fix blame highlighting not appearing by using StateField instead of ViewPlugin
- Remove final sync step that was destroying blame attribution
- Add tests for common prefix stripping behavior

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: btucker

src/claude_code_transcripts/code_view.py

@@ -577,27 +577,10 @@ def build_file_history_repo(
         )
         repo.index.commit(metadata)
 
-    # Final sync: for files where our reconstruction diverged from HEAD,
-    # replace with HEAD's content to ensure correct final state
-    if actual_repo and actual_repo_root:
-        for orig_path, rel_path in path_mapping.items():
-            full_path = temp_dir / rel_path
-            if not full_path.exists():
-                continue
-
-            try:
-                file_rel_path = os.path.relpath(orig_path, actual_repo_root)
-                blob = actual_repo.head.commit.tree / file_rel_path
-                head_content = blob.data_stream.read().decode("utf-8")
-                our_content = full_path.read_text()
-
-                # If content differs, use HEAD's content
-                if our_content != head_content:
-                    full_path.write_text(head_content)
-                    repo.index.add([rel_path])
-                    repo.index.commit("{}")  # Final sync commit
-            except (KeyError, TypeError, UnicodeDecodeError):
-                pass  # File not in HEAD or not text
+    # Note: We intentionally skip final sync here to preserve blame attribution.
+    # The displayed content may not exactly match HEAD, but blame tracking
+    # of which operations modified which lines is more important for the
+    # code viewer's purpose.
 
     return repo, temp_dir, path_mapping
 
@@ -671,18 +654,45 @@ def get_file_content_from_repo(repo: Repo, file_path: str) -> Optional[str]:
 def build_file_tree(file_states: Dict[str, FileState]) -> Dict[str, Any]:
     """Build a nested dict structure for file tree UI.
 
+    Common directory prefixes shared by all files are stripped to keep the
+    tree compact.
+
     Args:
         file_states: Dict mapping file paths to FileState objects.
 
     Returns:
         Nested dict where keys are path components and leaves are FileState objects.
     """
+    if not file_states:
+        return {}
+
+    # Split all paths into parts
+    all_parts = [Path(fp).parts for fp in file_states.keys()]
+
+    # Find the common prefix (directory components shared by all files)
+    # We want to strip directories, not filename components
+    common_prefix_len = 0
+    if all_parts:
+        # Find minimum path depth (excluding filename)
+        min_dir_depth = min(len(parts) - 1 for parts in all_parts)
+
+        for i in range(min_dir_depth):
+            # Check if all paths have the same component at position i
+            first_part = all_parts[0][i]
+            if all(parts[i] == first_part for parts in all_parts):
+                common_prefix_len = i + 1
+            else:
+                break
+
     tree: Dict[str, Any] = {}
 
     for file_path, file_state in file_states.items():
         # Normalize path and split into components
         parts = Path(file_path).parts
 
+        # Strip common prefix
+        parts = parts[common_prefix_len:]
+
         # Navigate/create the nested structure
         current = tree
         for i, part in enumerate(parts[:-1]):  # All but the last part (directories)

src/claude_code_transcripts/templates/code_view.js

@@ -353,9 +353,11 @@ function createEditor(container, content, blameRanges, filePath) {
     const { colorMap, msgNumMap } = buildRangeMaps(blameRanges);
     const rangeDecorations = createRangeDecorations(blameRanges, doc, colorMap, msgNumMap);
 
-    // Static decorations plugin
-    const rangeDecorationsPlugin = ViewPlugin.define(() => ({}), {
-        decorations: () => rangeDecorations
+    // Static decorations as a StateField (more reliable than ViewPlugin for static decorations)
+    const rangeDecorationsField = StateField.define({
+        create() { return rangeDecorations; },
+        update(decorations) { return decorations; },
+        provide: f => EditorView.decorations.from(f)
     });
 
     // Click handler plugin
@@ -414,7 +416,7 @@ function createEditor(container, content, blameRanges, filePath) {
         EditorView.lineWrapping,
         syntaxHighlighting(defaultHighlightStyle),
         getLanguageExtension(filePath),
-        rangeDecorationsPlugin,
+        rangeDecorationsField,
         activeRangeField,
         clickHandler,
     ];

tests/test_code_view.py

@@ -235,14 +235,12 @@ def test_builds_simple_tree(self):
 
         tree = build_file_tree(file_states)
 
-        # Check structure - should have /src and /tests at root level
-        assert "/" in tree
-        root = tree["/"]
-        assert "src" in root
-        assert "tests" in root
-        assert "main.py" in root["src"]
-        assert "utils.py" in root["src"]
-        assert "test_main.py" in root["tests"]
+        # Check structure - common "/" prefix stripped, src and tests at root
+        assert "src" in tree
+        assert "tests" in tree
+        assert "main.py" in tree["src"]
+        assert "utils.py" in tree["src"]
+        assert "test_main.py" in tree["tests"]
 
     def test_empty_file_states(self):
         """Test building tree from empty file states."""
@@ -254,11 +252,9 @@ def test_single_file(self):
         file_states = {"/path/to/file.py": FileState(file_path="/path/to/file.py")}
         tree = build_file_tree(file_states)
 
-        assert "/" in tree
-        current = tree["/"]
-        assert "path" in current
-        assert "to" in current["path"]
-        assert "file.py" in current["path"]["to"]
+        # Single file: all parent directories are common prefix, only filename remains
+        assert "file.py" in tree
+        assert isinstance(tree["file.py"], FileState)
 
     def test_file_state_is_leaf(self):
         """Test that FileState objects are the leaves of the tree."""
@@ -267,11 +263,63 @@ def test_file_state_is_leaf(self):
 
         tree = build_file_tree(file_states)
 
-        # Navigate to the leaf
-        leaf = tree["/"]["src"]["main.py"]
+        # Single file: common prefix stripped, just the filename at root
+        leaf = tree["main.py"]
         assert isinstance(leaf, FileState)
         assert leaf.file_path == "/src/main.py"
 
+    def test_strips_common_prefix(self):
+        """Test that common directory prefixes are stripped from the tree."""
+        file_states = {
+            "/Users/alice/projects/myapp/src/main.py": FileState(
+                file_path="/Users/alice/projects/myapp/src/main.py"
+            ),
+            "/Users/alice/projects/myapp/src/utils.py": FileState(
+                file_path="/Users/alice/projects/myapp/src/utils.py"
+            ),
+            "/Users/alice/projects/myapp/tests/test_main.py": FileState(
+                file_path="/Users/alice/projects/myapp/tests/test_main.py"
+            ),
+        }
+
+        tree = build_file_tree(file_states)
+
+        # Common prefix /Users/alice/projects/myapp should be stripped
+        # Tree should start with src and tests at the root
+        assert "src" in tree
+        assert "tests" in tree
+        assert "Users" not in tree
+        assert "main.py" in tree["src"]
+        assert "utils.py" in tree["src"]
+        assert "test_main.py" in tree["tests"]
+
+    def test_strips_common_prefix_single_common_dir(self):
+        """Test stripping when all files share exactly one common parent."""
+        file_states = {
+            "/src/foo.py": FileState(file_path="/src/foo.py"),
+            "/src/bar.py": FileState(file_path="/src/bar.py"),
+        }
+
+        tree = build_file_tree(file_states)
+
+        # /src is common, so tree should just have the files
+        assert "foo.py" in tree
+        assert "bar.py" in tree
+        assert "src" not in tree
+
+    def test_no_common_prefix_preserved(self):
+        """Test that paths with no common prefix are preserved."""
+        file_states = {
+            "/src/main.py": FileState(file_path="/src/main.py"),
+            "/lib/utils.py": FileState(file_path="/lib/utils.py"),
+        }
+
+        tree = build_file_tree(file_states)
+
+        # Only "/" is common, so src and lib should be at root
+        assert "src" in tree
+        assert "lib" in tree
+
 
 class TestCodeViewDataDataclass:
     """Tests for the CodeViewData dataclass."""