fix: expand bandit --exclude paths into globs so nested files are pruned

desloppify/languages/python/detectors/bandit_adapter.py

@@ -185,6 +185,43 @@ def _to_security_entry(
     }
 
 
+def _exclude_globs(exclude_dirs: list[str]) -> list[str]:
+    """Expand absolute exclude paths into bandit-friendly glob patterns.
+
+    Bandit's ``--exclude`` is matched against filenames it discovers during
+    its recursive walk. When desloppify hands it absolute directory paths
+    (e.g. ``/repo/.claude``), bandit only filters files whose name *equals*
+    one of those paths — directories *under* the exclude (e.g.
+    ``/repo/.claude/worktrees/foo.py``) still get scanned because their
+    full filename does not equal the exclude string.
+
+    Expanding each absolute path into ``**/<basename>/**`` (and a sibling
+    ``<basename>`` form for the directory itself) ensures bandit prunes the
+    whole subtree the way the rest of desloppify already does. The
+    original absolute paths are kept as a belt-and-braces fallback.
+    """
+    expanded: list[str] = []
+    seen: set[str] = set()
+    for raw in exclude_dirs:
+        if not raw:
+            continue
+        if raw not in seen:
+            expanded.append(raw)
+            seen.add(raw)
+        # Walk every path component and emit a glob; this catches both
+        # top-level (``.claude``) and nested (``.claude/worktrees``) excludes
+        # without requiring callers to know the layout.
+        parts = [p for p in raw.replace("\\", "/").split("/") if p]
+        for part in parts:
+            if not part or part in {"*", "**"}:
+                continue
+            for candidate in (f"**/{part}", f"**/{part}/**"):
+                if candidate not in seen:
+                    expanded.append(candidate)
+                    seen.add(candidate)
+    return expanded
+
+
 def detect_with_bandit(
     path: Path,
     zone_map: FileZoneMap | None,
@@ -197,9 +234,11 @@ def detect_with_bandit(
     Parameters
     ----------
     exclude_dirs:
-        Absolute directory paths to pass to bandit's ``--exclude`` flag.
-        When non-empty, bandit will skip these directories during its
-        recursive scan.
+        Absolute directory paths to skip. Each path is expanded into a
+        ``**/<name>/**`` glob (in addition to the original absolute path)
+        before being passed to bandit's ``--exclude`` flag, so that nested
+        files under the exclude are pruned, not just the directory entry
+        itself.
     skip_tests:
         Bandit test IDs to suppress via ``--skip`` (e.g. ``["B101", "B601"]``).
         Allows users to disable entire rule families from ``config.json``.
@@ -214,7 +253,7 @@ def detect_with_bandit(
         "--quiet",
     ]
     if exclude_dirs:
-        cmd.extend(["--exclude", ",".join(exclude_dirs)])
+        cmd.extend(["--exclude", ",".join(_exclude_globs(exclude_dirs))])
     if skip_tests:
         cmd.extend(["--skip", ",".join(skip_tests)])
     cmd.append(str(path.resolve()))

desloppify/tests/detectors/test_external_adapters.py

@@ -487,6 +487,36 @@ def _capture_run(cmd, **kwargs):
 
         assert "--exclude" not in captured_cmd
 
+    def test_exclude_dirs_expanded_to_glob_for_nested_pruning(self):
+        """REGRESSION: bandit's --exclude must prune nested files, not just dirs.
+
+        When given a bare absolute path like ``/project/.claude``, bandit
+        only filters files whose full name equals that string; files
+        beneath the directory are still scanned. ``detect_with_bandit``
+        must therefore expand each path into ``**/<name>/**`` globs.
+        """
+        captured: list[str] = []
+
+        def _capture_run(cmd, **kwargs):
+            captured.extend(cmd)
+            mock_result = MagicMock()
+            mock_result.stdout = self._bandit_result([])
+            return mock_result
+
+        with patch("subprocess.run", side_effect=_capture_run):
+            detect_with_bandit(
+                Path("/project"),
+                zone_map=None,
+                exclude_dirs=["/project/.claude", "/project/.claude/worktrees"],
+            )
+
+        idx = captured.index("--exclude")
+        exclude_value = captured[idx + 1]
+        assert "/project/.claude" in exclude_value
+        assert "**/.claude" in exclude_value
+        assert "**/.claude/**" in exclude_value
+        assert "**/worktrees/**" in exclude_value
+
 
 class TestBanditExcludeIntegration:
     """Verify PythonConfig passes exclusion dirs to bandit."""