Make empty --include mean "anything goes", simplify `gen_python_files_in_dir`

diff --git a/black.py b/black.py
index 7587ba82161e2b9ed6f70d9ebc60bf18a1f341e1..8ac6d87e7c25d35ed4ecde193bf47f6b3a81006b 100644 (file)
--- a/black.py
+++ b/black.py
@@ -190,8 +190,10 @@ class FileMode(Flag):
     default=DEFAULT_INCLUDES,
     help=(
         "A regular expression that matches files and directories that should be "
-        "included on recursive searches. On Windows, use forward slashes for "
-        "directories."
+        "included on recursive searches.  An empty value means all files are "
+        "included regardless of the name.  Use forward slashes for directories on "
+        "all platforms (Windows, too).  Exclusions are calculated first, inclusions "
+        "later."
     ),
     show_default=True,
 )
@@ -201,8 +203,9 @@ class FileMode(Flag):
     default=DEFAULT_EXCLUDES,
     help=(
         "A regular expression that matches files and directories that should be "
-        "excluded on recursive searches. On Windows, use forward slashes for "
-        "directories."
+        "excluded on recursive searches.  An empty value means no paths are excluded. "
+        "Use forward slashes for directories on all platforms (Windows, too).  "
+        "Exclusions are calculated first, inclusions later."
     ),
     show_default=True,
 )
@@ -2794,28 +2797,20 @@ def gen_python_files_in_dir(
     """Generate all files under `path` whose paths are not excluded by the
     `exclude` regex, but are included by the `include` regex.
     """
-
     for child in path.iterdir():
-        searchable_path = str(child.as_posix())
-        if Path(child.parts[0]).is_dir():
-            searchable_path = "/" + searchable_path
+        normalized_path = child.resolve().as_posix()
         if child.is_dir():
-            searchable_path = searchable_path + "/"
-            exclude_match = exclude.search(searchable_path)
-            if exclude_match and len(exclude_match.group()) > 0:
-                continue
+            normalized_path += "/"
+        exclude_match = exclude.search(normalized_path)
+        if exclude_match and exclude_match.group(0):
+            continue
 
+        if child.is_dir():
             yield from gen_python_files_in_dir(child, include, exclude)
 
-        else:
-            include_match = include.search(searchable_path)
-            exclude_match = exclude.search(searchable_path)
-            if (
-                child.is_file()
-                and include_match
-                and len(include_match.group()) > 0
-                and (not exclude_match or len(exclude_match.group()) == 0)
-            ):
+        elif child.is_file():
+            include_match = include.search(normalized_path)
+            if include_match:
                 yield child
 
 

diff --git a/tests/test_black.py b/tests/test_black.py
index c10dd1d90c3d3d217895ea52ba644010913a5ce6..08a3f31696df5c75fa745299dd3861ca7437b947 100644 (file)
--- a/tests/test_black.py
+++ b/tests/test_black.py
@@ -868,24 +868,35 @@ class BlackTestCase(unittest.TestCase):
         path = THIS_DIR / "include_exclude_tests"
         empty = re.compile(r"")
         sources: List[Path] = []
+        expected = [
+            Path(path / "b/exclude/a.pie"),
+            Path(path / "b/exclude/a.py"),
+            Path(path / "b/exclude/a.pyi"),
+            Path(path / "b/dont_exclude/a.pie"),
+            Path(path / "b/dont_exclude/a.py"),
+            Path(path / "b/dont_exclude/a.pyi"),
+            Path(path / "b/.definitely_exclude/a.pie"),
+            Path(path / "b/.definitely_exclude/a.py"),
+            Path(path / "b/.definitely_exclude/a.pyi"),
+        ]
         sources.extend(
             black.gen_python_files_in_dir(
                 path, empty, re.compile(black.DEFAULT_EXCLUDES)
             )
         )
-        self.assertEqual([], (sources))
+        self.assertEqual(sorted(expected), sorted(sources))
 
     def test_empty_exclude(self) -> None:
         path = THIS_DIR / "include_exclude_tests"
         empty = re.compile(r"")
         sources: List[Path] = []
         expected = [
-            Path(THIS_DIR / "include_exclude_tests/b/dont_exclude/a.py"),
-            Path(THIS_DIR / "include_exclude_tests/b/dont_exclude/a.pyi"),
-            Path(THIS_DIR / "include_exclude_tests/b/exclude/a.py"),
-            Path(THIS_DIR / "include_exclude_tests/b/exclude/a.pyi"),
-            Path(THIS_DIR / "include_exclude_tests/b/.definitely_exclude/a.py"),
-            Path(THIS_DIR / "include_exclude_tests/b/.definitely_exclude/a.pyi"),
+            Path(path / "b/dont_exclude/a.py"),
+            Path(path / "b/dont_exclude/a.pyi"),
+            Path(path / "b/exclude/a.py"),
+            Path(path / "b/exclude/a.pyi"),
+            Path(path / "b/.definitely_exclude/a.py"),
+            Path(path / "b/.definitely_exclude/a.pyi"),
         ]
         sources.extend(
             black.gen_python_files_in_dir(