Fix: respect .gitignore files in all levels.

src/black/files.py

@@ -212,7 +212,7 @@ def gen_python_files(
                 extend_exclude,
                 force_exclude,
                 report,
-                gitignore,
+                gitignore + get_gitignore(child),
             )
 
         elif child.is_file():

tests/data/gitignore_levels_tests/.gitignore

@@ -0,0 +1 @@
+ignored_in_root.py

tests/data/gitignore_levels_tests/child_dir/.gitignore

@@ -0,0 +1 @@
+ignored_in_child.py

tests/data/gitignore_levels_tests/child_dir/ignored_in_child.py

@@ -0,0 +1 @@
+# should be excluded

tests/data/gitignore_levels_tests/child_dir/ignored_in_root.py

@@ -0,0 +1 @@
+# should be excluded

tests/data/gitignore_levels_tests/child_dir/included.py

@@ -0,0 +1 @@
+# should be included

tests/data/gitignore_levels_tests/ignored_in_child.py

@@ -0,0 +1 @@
+# should be included

tests/data/gitignore_levels_tests/ignored_in_root.py

@@ -0,0 +1 @@
+# should be excluded

tests/data/gitignore_levels_tests/included.py

@@ -0,0 +1 @@
+# should be included

tests/test_black.py

@@ -1703,6 +1703,32 @@ def test_gitignore_exclude(self) -> None:
         )
         self.assertEqual(sorted(expected), sorted(sources))
 
+    def test_respect_gitignore_levels(self) -> None:
+        path = Path(THIS_DIR / "data" / "gitignore_levels_tests")
+        include = re.compile(r"\.pyi?$")
+        exclude = re.compile(r"")
+        root_gitignore = black.files.get_gitignore(path)
+        report = black.Report()
+        expected: List[Path] = [
+            Path(path / "included.py"),
+            Path(path / "ignored_in_child.py"),
+            Path(path / "child_dir/included.py"),
+        ]
+        this_abs = THIS_DIR.resolve()
+        sources = list(
+            black.gen_python_files(
+                path.iterdir(),
+                this_abs,
+                include,
+                exclude,
+                None,
+                None,
+                report,
+                root_gitignore,
+            )
+        )
+        self.assertEqual(sorted(expected), sorted(sources))
+
     def test_empty_include(self) -> None:
         path = THIS_DIR / "data" / "include_exclude_tests"
         report = black.Report()