chore: dump docs deps and pre-commit hooks (#2676)

[etc/vim.git] / src / black / __init__.py

diff --git a/src/black/__init__.py b/src/black/__init__.py
index a5ddec9122105cae9393d126c92f3c3c5bfb3ec3..59018d00de469c5e276a98f84cca506e44c29d80 100644 (file)
--- a/src/black/__init__.py
+++ b/src/black/__init__.py
@@ -10,7 +10,7 @@ from multiprocessing import Manager, freeze_support
 import os
 from pathlib import Path
 from pathspec.patterns.gitwildmatch import GitWildMatchPatternError
-import regex as re
+import re
 import signal
 import sys
 import tokenize
@@ -40,7 +40,7 @@ from black.nodes import STARS, syms, is_simple_decorator_expression
 from black.lines import Line, EmptyLineTracker
 from black.linegen import transform_line, LineGenerator, LN
 from black.comments import normalize_fmt_off
-from black.mode import Mode, TargetVersion
+from black.mode import FUTURE_FLAG_TO_FEATURE, Mode, TargetVersion
 from black.mode import Feature, supports_feature, VERSION_TO_FEATURES
 from black.cache import read_cache, write_cache, get_cache_info, filter_cached, Cache
 from black.concurrency import cancel, shutdown, maybe_install_uvloop
@@ -57,6 +57,7 @@ from black.handle_ipynb_magics import (
     remove_trailing_semicolon,
     put_trailing_semicolon_back,
     TRANSFORMED_MAGICS,
+    PYTHON_CELL_MAGICS,
     jupyter_dependencies_are_installed,
 )
 
@@ -176,12 +177,12 @@ def validate_regex(
 ) -> Optional[Pattern[str]]:
     try:
         return re_compile_maybe_verbose(value) if value is not None else None
-    except re.error:
-        raise click.BadParameter("Not a valid regular expression") from None
+    except re.error as e:
+        raise click.BadParameter(f"Not a valid regular expression: {e}") from None
 
 
 @click.command(
-    context_settings=dict(help_option_names=["-h", "--help"]),
+    context_settings={"help_option_names": ["-h", "--help"]},
     # While Click does set this field automatically using the docstring, mypyc
     # (annoyingly) strips 'em so we need to set it here too.
     help="The uncompromising code formatter.",
@@ -687,7 +688,7 @@ def reformat_many(
         worker_count = min(worker_count, 60)
     try:
         executor = ProcessPoolExecutor(max_workers=worker_count)
-    except (ImportError, OSError):
+    except (ImportError, NotImplementedError, OSError):
         # we arrive here if the underlying system does not support multi-processing
         # like in AWS Lambda or Termux, in which case we gracefully fallback to
         # a ThreadPoolExecutor with just a single worker (more workers would not do us
@@ -943,7 +944,9 @@ def format_file_contents(src_contents: str, *, fast: bool, mode: Mode) -> FileCo
 
 
 def validate_cell(src: str) -> None:
-    """Check that cell does not already contain TransformerManager transformations.
+    """Check that cell does not already contain TransformerManager transformations,
+    or non-Python cell magics, which might cause tokenizer_rt to break because of
+    indentations.
 
     If a cell contains ``!ls``, then it'll be transformed to
     ``get_ipython().system('ls')``. However, if the cell originally contained
@@ -959,6 +962,8 @@ def validate_cell(src: str) -> None:
     """
     if any(transformed_magic in src for transformed_magic in TRANSFORMED_MAGICS):
         raise NothingChanged
+    if src[:2] == "%%" and src.split()[0][2:] not in PYTHON_CELL_MAGICS:
+        raise NothingChanged
 
 
 def format_cell(src: str, *, fast: bool, mode: Mode) -> str:
@@ -1075,7 +1080,7 @@ def format_str(src_contents: str, *, mode: Mode) -> FileContent:
     if mode.target_versions:
         versions = mode.target_versions
     else:
-        versions = detect_target_versions(src_node)
+        versions = detect_target_versions(src_node, future_imports=future_imports)
 
     # TODO: fully drop support and this code hopefully in January 2022 :D
     if TargetVersion.PY27 in mode.target_versions or versions == {TargetVersion.PY27}:
@@ -1127,7 +1132,9 @@ def decode_bytes(src: bytes) -> Tuple[FileContent, Encoding, NewLine]:
         return tiow.read(), encoding, newline
 
 
-def get_features_used(node: Node) -> Set[Feature]:  # noqa: C901
+def get_features_used(  # noqa: C901
+    node: Node, *, future_imports: Optional[Set[str]] = None
+) -> Set[Feature]:
     """Return a set of (relatively) new Python features used in this file.
 
     Currently looking for:
@@ -1137,9 +1144,17 @@ def get_features_used(node: Node) -> Set[Feature]:  # noqa: C901
     - positional only arguments in function signatures and lambdas;
     - assignment expression;
     - relaxed decorator syntax;
+    - usage of __future__ flags (annotations);
     - print / exec statements;
     """
     features: Set[Feature] = set()
+    if future_imports:
+        features |= {
+            FUTURE_FLAG_TO_FEATURE[future_import]
+            for future_import in future_imports
+            if future_import in FUTURE_FLAG_TO_FEATURE
+        }
+
     for n in node.pre_order():
         if n.type == token.STRING:
             value_head = n.value[:2]  # type: ignore
@@ -1224,9 +1239,11 @@ def get_features_used(node: Node) -> Set[Feature]:  # noqa: C901
     return features
 
 
-def detect_target_versions(node: Node) -> Set[TargetVersion]:
+def detect_target_versions(
+    node: Node, *, future_imports: Optional[Set[str]] = None
+) -> Set[TargetVersion]:
     """Detect the version to target based on the nodes used."""
-    features = get_features_used(node)
+    features = get_features_used(node, future_imports=future_imports)
     return {
         version for version in TargetVersion if features <= VERSION_TO_FEATURES[version]
     }