X-Git-Url: https://git.madduck.net/etc/vim.git/blobdiff_plain/f2ea461e9e9fa5c47bb61fd72d512c748928badc..95c03b9638e44eb76611a0e005d447472a4f2f97:/src/black/__init__.py diff --git a/src/black/__init__.py b/src/black/__init__.py index c61bc8c..eaf72f9 100644 --- a/src/black/__init__.py +++ b/src/black/__init__.py @@ -1,4 +1,6 @@ import asyncio +from json.decoder import JSONDecodeError +import json from concurrent.futures import Executor, ThreadPoolExecutor, ProcessPoolExecutor from contextlib import contextmanager from datetime import datetime @@ -7,7 +9,8 @@ import io from multiprocessing import Manager, freeze_support import os from pathlib import Path -import regex as re +from pathspec.patterns.gitwildmatch import GitWildMatchPatternError +import re import signal import sys import tokenize @@ -18,34 +21,48 @@ from typing import ( Generator, Iterator, List, + MutableMapping, Optional, Pattern, + Sequence, Set, Sized, Tuple, Union, ) -from dataclasses import replace import click +from click.core import ParameterSource +from dataclasses import replace +from mypy_extensions import mypyc_attr from black.const import DEFAULT_LINE_LENGTH, DEFAULT_INCLUDES, DEFAULT_EXCLUDES from black.const import STDIN_PLACEHOLDER from black.nodes import STARS, syms, is_simple_decorator_expression +from black.nodes import is_string_token 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 -from black.output import dump_to_file, diff, color_diff, out, err -from black.report import Report, Changed +from black.concurrency import cancel, shutdown, maybe_install_uvloop +from black.output import dump_to_file, ipynb_diff, diff, color_diff, out, err +from black.report import Report, Changed, NothingChanged from black.files import find_project_root, find_pyproject_toml, parse_pyproject_toml from black.files import gen_python_files, get_gitignore, normalize_path_maybe_ignore from black.files import wrap_stream_for_windows from black.parsing import InvalidInput # noqa F401 from black.parsing import lib2to3_parse, parse_ast, stringify_ast +from black.handle_ipynb_magics import ( + mask_cell, + unmask_cell, + remove_trailing_semicolon, + put_trailing_semicolon_back, + TRANSFORMED_MAGICS, + PYTHON_CELL_MAGICS, + jupyter_dependencies_are_installed, +) # lib2to3 fork @@ -54,6 +71,7 @@ from blib2to3.pgen2 import token from _black_version import version as __version__ +COMPILED = Path(__file__).suffix in (".pyd", ".so") # types FileContent = str @@ -61,10 +79,6 @@ Encoding = str NewLine = str -class NothingChanged(UserWarning): - """Raised when reformatted code is the same as source.""" - - class WriteBack(Enum): NO = 0 YES = 1 @@ -88,6 +102,8 @@ class WriteBack(Enum): # Legacy name, left for integrations. FileMode = Mode +DEFAULT_WORKERS = os.cpu_count() + def read_pyproject_toml( ctx: click.Context, param: click.Parameter, value: Optional[str] @@ -107,7 +123,7 @@ def read_pyproject_toml( except (OSError, ValueError) as e: raise click.FileError( filename=value, hint=f"Error reading configuration file: {e}" - ) + ) from None if not config: return None @@ -161,14 +177,19 @@ def validate_regex( ctx: click.Context, param: click.Parameter, value: Optional[str], -) -> Optional[Pattern]: +) -> 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") + 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"])) +@click.command( + 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.", +) @click.option("-c", "--code", type=str, help="Format the code passed in as a string.") @click.option( "-l", @@ -197,6 +218,24 @@ def validate_regex( " when piping source on standard input)." ), ) +@click.option( + "--ipynb", + is_flag=True, + help=( + "Format all input files like Jupyter Notebooks regardless of file extension " + "(useful when piping source on standard input)." + ), +) +@click.option( + "--python-cell-magics", + multiple=True, + help=( + "When processing Jupyter Notebooks, add the given magic to the list" + f" of known python-magics ({', '.join(PYTHON_CELL_MAGICS)})." + " Useful for formatting cells with custom python magics." + ), + default=[], +) @click.option( "-S", "--skip-string-normalization", @@ -213,9 +252,14 @@ def validate_regex( "--experimental-string-processing", is_flag=True, hidden=True, + help="(DEPRECATED and now included in --preview) Normalize string literals.", +) +@click.option( + "--preview", + is_flag=True, help=( - "Experimental option that performs more normalization on string literals." - " Currently disabled because it leads to some crashes." + "Enable potentially disruptive style changes that will be added to Black's main" + " functionality in the next major release." ), ) @click.option( @@ -242,6 +286,14 @@ def validate_regex( is_flag=True, help="If --fast given, skip temporary sanity checks. [default: --safe]", ) +@click.option( + "--required-version", + type=str, + help=( + "Require a specific version of Black to be running (useful for unifying results" + " across many environments e.g. with a pyproject.toml file)." + ), +) @click.option( "--include", type=str, @@ -295,6 +347,14 @@ def validate_regex( "editors that rely on using stdin." ), ) +@click.option( + "-W", + "--workers", + type=click.IntRange(min=1), + default=DEFAULT_WORKERS, + show_default=True, + help="Number of parallel workers", +) @click.option( "-q", "--quiet", @@ -313,7 +373,10 @@ def validate_regex( " due to exclusion patterns." ), ) -@click.version_option(version=__version__) +@click.version_option( + version=__version__, + message=f"%(prog)s, %(version)s (compiled: {'yes' if COMPILED else 'no'})", +) @click.argument( "src", nargs=-1, @@ -321,6 +384,7 @@ def validate_regex( exists=True, file_okay=True, dir_okay=True, readable=True, allow_dash=True ), is_eager=True, + metavar="SRC ...", ) @click.option( "--config", @@ -347,20 +411,68 @@ def main( color: bool, fast: bool, pyi: bool, + ipynb: bool, + python_cell_magics: Sequence[str], skip_string_normalization: bool, skip_magic_trailing_comma: bool, experimental_string_processing: bool, + preview: bool, quiet: bool, verbose: bool, - include: Pattern, - exclude: Optional[Pattern], - extend_exclude: Optional[Pattern], - force_exclude: Optional[Pattern], + required_version: Optional[str], + include: Pattern[str], + exclude: Optional[Pattern[str]], + extend_exclude: Optional[Pattern[str]], + force_exclude: Optional[Pattern[str]], stdin_filename: Optional[str], + workers: int, src: Tuple[str, ...], config: Optional[str], ) -> None: """The uncompromising code formatter.""" + ctx.ensure_object(dict) + root, method = find_project_root(src) if code is None else (None, None) + ctx.obj["root"] = root + + if verbose: + if root: + out( + f"Identified `{root}` as project root containing a {method}.", + fg="blue", + ) + + normalized = [ + (normalize_path_maybe_ignore(Path(source), root), source) + for source in src + ] + srcs_string = ", ".join( + [ + f'"{_norm}"' + if _norm + else f'\033[31m"{source} (skipping - invalid)"\033[34m' + for _norm, source in normalized + ] + ) + out(f"Sources to be formatted: {srcs_string}", fg="blue") + + if config: + config_source = ctx.get_parameter_source("config") + if config_source in (ParameterSource.DEFAULT, ParameterSource.DEFAULT_MAP): + out("Using configuration from project root.", fg="blue") + else: + out(f"Using configuration in '{config}'.", fg="blue") + + error_msg = "Oh no! 💥 💔 💥" + if required_version and required_version != __version__: + err( + f"{error_msg} The required version `{required_version}` does not match" + f" the running version `{__version__}`!" + ) + ctx.exit(1) + if ipynb and pyi: + err("Cannot pass both `pyi` and `ipynb` flags!") + ctx.exit(1) + write_back = WriteBack.from_configuration(check=check, diff=diff, color=color) if target_version: versions = set(target_version) @@ -371,53 +483,74 @@ def main( target_versions=versions, line_length=line_length, is_pyi=pyi, + is_ipynb=ipynb, string_normalization=not skip_string_normalization, magic_trailing_comma=not skip_magic_trailing_comma, experimental_string_processing=experimental_string_processing, + preview=preview, + python_cell_magics=set(python_cell_magics), ) - if config and verbose: - out(f"Using configuration from {config}.", bold=False, fg="blue") + if code is not None: - print(format_str(code, mode=mode)) - ctx.exit(0) - report = Report(check=check, diff=diff, quiet=quiet, verbose=verbose) - sources = get_sources( - ctx=ctx, - src=src, - quiet=quiet, - verbose=verbose, - include=include, - exclude=exclude, - extend_exclude=extend_exclude, - force_exclude=force_exclude, - report=report, - stdin_filename=stdin_filename, - ) + # Run in quiet mode by default with -c; the extra output isn't useful. + # You can still pass -v to get verbose output. + quiet = True - path_empty( - sources, - "No Python files are present to be formatted. Nothing to do 😴", - quiet, - verbose, - ctx, - ) + report = Report(check=check, diff=diff, quiet=quiet, verbose=verbose) - if len(sources) == 1: - reformat_one( - src=sources.pop(), - fast=fast, - write_back=write_back, - mode=mode, - report=report, + if code is not None: + reformat_code( + content=code, fast=fast, write_back=write_back, mode=mode, report=report ) else: - reformat_many( - sources=sources, fast=fast, write_back=write_back, mode=mode, report=report + try: + sources = get_sources( + ctx=ctx, + src=src, + quiet=quiet, + verbose=verbose, + include=include, + exclude=exclude, + extend_exclude=extend_exclude, + force_exclude=force_exclude, + report=report, + stdin_filename=stdin_filename, + ) + except GitWildMatchPatternError: + ctx.exit(1) + + path_empty( + sources, + "No Python files are present to be formatted. Nothing to do 😴", + quiet, + verbose, + ctx, ) + if len(sources) == 1: + reformat_one( + src=sources.pop(), + fast=fast, + write_back=write_back, + mode=mode, + report=report, + ) + else: + reformat_many( + sources=sources, + fast=fast, + write_back=write_back, + mode=mode, + report=report, + workers=workers, + ) + if verbose or not quiet: - out("Oh no! 💥 💔 💥" if report.return_code else "All done! ✨ 🍰 ✨") - click.secho(str(report), err=True) + if code is None and (verbose or report.change_count or report.failure_count): + out() + out(error_msg if report.return_code else "All done! ✨ 🍰 ✨") + if code is None: + click.echo(str(report), err=True) ctx.exit(report.return_code) @@ -435,14 +568,12 @@ def get_sources( stdin_filename: Optional[str], ) -> Set[Path]: """Compute the set of files to be formatted.""" - - root = find_project_root(src) sources: Set[Path] = set() path_empty(src, "No Path provided. Nothing to do 😴", quiet, verbose, ctx) if exclude is None: exclude = re_compile_maybe_verbose(DEFAULT_EXCLUDES) - gitignore = get_gitignore(root) + gitignore = get_gitignore(ctx.obj["root"]) else: gitignore = None @@ -455,7 +586,7 @@ def get_sources( is_stdin = False if is_stdin or p.is_file(): - normalized_path = normalize_path_maybe_ignore(p, root, report) + normalized_path = normalize_path_maybe_ignore(p, ctx.obj["root"], report) if normalized_path is None: continue @@ -472,18 +603,25 @@ def get_sources( if is_stdin: p = Path(f"{STDIN_PLACEHOLDER}{str(p)}") + if p.suffix == ".ipynb" and not jupyter_dependencies_are_installed( + verbose=verbose, quiet=quiet + ): + continue + sources.add(p) elif p.is_dir(): sources.update( gen_python_files( p.iterdir(), - root, + ctx.obj["root"], include, exclude, extend_exclude, force_exclude, report, gitignore, + verbose=verbose, + quiet=quiet, ) ) elif s == "-": @@ -499,11 +637,36 @@ def path_empty( """ Exit if there is no `src` provided for formatting """ - if not src and (verbose or not quiet): - out(msg) + if not src: + if verbose or not quiet: + out(msg) ctx.exit(0) +def reformat_code( + content: str, fast: bool, write_back: WriteBack, mode: Mode, report: Report +) -> None: + """ + Reformat and print out `content` without spawning child processes. + Similar to `reformat_one`, but for string content. + + `fast`, `write_back`, and `mode` options are passed to + :func:`format_file_in_place` or :func:`format_stdin_to_stdout`. + """ + path = Path("") + try: + changed = Changed.NO + if format_stdin_to_stdout( + content=content, fast=fast, write_back=write_back, mode=mode + ): + changed = Changed.YES + report.done(path, changed) + except Exception as exc: + if report.verbose: + traceback.print_exc() + report.failed(path, str(exc)) + + def reformat_one( src: Path, fast: bool, write_back: WriteBack, mode: Mode, report: "Report" ) -> None: @@ -528,6 +691,8 @@ def reformat_one( if is_stdin: if src.suffix == ".pyi": mode = replace(mode, is_pyi=True) + elif src.suffix == ".ipynb": + mode = replace(mode, is_ipynb=True) if format_stdin_to_stdout(fast=fast, write_back=write_back, mode=mode): changed = Changed.YES else: @@ -553,19 +718,28 @@ def reformat_one( report.failed(src, str(exc)) +# diff-shades depends on being to monkeypatch this function to operate. I know it's +# not ideal, but this shouldn't cause any issues ... hopefully. ~ichard26 +@mypyc_attr(patchable=True) def reformat_many( - sources: Set[Path], fast: bool, write_back: WriteBack, mode: Mode, report: "Report" + sources: Set[Path], + fast: bool, + write_back: WriteBack, + mode: Mode, + report: "Report", + workers: Optional[int], ) -> None: """Reformat multiple files using a ProcessPoolExecutor.""" executor: Executor loop = asyncio.get_event_loop() - worker_count = os.cpu_count() + worker_count = workers if workers is not None else DEFAULT_WORKERS if sys.platform == "win32": # Work around https://bugs.python.org/issue26903 + assert worker_count is not None 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 @@ -656,7 +830,10 @@ async def schedule_formatting( sources_to_cache.append(src) report.done(src, changed) if cancelled: - await asyncio.gather(*cancelled, loop=loop, return_exceptions=True) + if sys.version_info >= (3, 7): + await asyncio.gather(*cancelled, return_exceptions=True) + else: + await asyncio.gather(*cancelled, loop=loop, return_exceptions=True) if sources_to_cache: write_cache(cache, sources_to_cache, mode) @@ -676,6 +853,8 @@ def format_file_in_place( """ if src.suffix == ".pyi": mode = replace(mode, is_pyi=True) + elif src.suffix == ".ipynb": + mode = replace(mode, is_ipynb=True) then = datetime.utcfromtimestamp(src.stat().st_mtime) with open(src, "rb") as buf: @@ -684,6 +863,10 @@ def format_file_in_place( dst_contents = format_file_contents(src_contents, fast=fast, mode=mode) except NothingChanged: return False + except JSONDecodeError: + raise ValueError( + f"File '{src}' cannot be parsed as valid Jupyter notebook." + ) from None if write_back == WriteBack.YES: with open(src, "w", encoding=encoding, newline=newline) as f: @@ -692,7 +875,10 @@ def format_file_in_place( now = datetime.utcnow() src_name = f"{src}\t{then} +0000" dst_name = f"{src}\t{now} +0000" - diff_contents = diff(src_contents, dst_contents, src_name, dst_name) + if mode.is_ipynb: + diff_contents = ipynb_diff(src_contents, dst_contents, src_name, dst_name) + else: + diff_contents = diff(src_contents, dst_contents, src_name, dst_name) if write_back == WriteBack.COLOR_DIFF: diff_contents = color_diff(diff_contents) @@ -712,16 +898,27 @@ def format_file_in_place( def format_stdin_to_stdout( - fast: bool, *, write_back: WriteBack = WriteBack.NO, mode: Mode + fast: bool, + *, + content: Optional[str] = None, + write_back: WriteBack = WriteBack.NO, + mode: Mode, ) -> bool: """Format file on stdin. Return True if changed. + If content is None, it's read from sys.stdin. + If `write_back` is YES, write reformatted code back to stdout. If it is DIFF, write a diff to stdout. The `mode` argument is passed to :func:`format_file_contents`. """ then = datetime.utcnow() - src, encoding, newline = decode_bytes(sys.stdin.buffer.read()) + + if content is None: + src, encoding, newline = decode_bytes(sys.stdin.buffer.read()) + else: + src, encoding, newline = content, "utf-8", "" + dst = src try: dst = format_file_contents(src, fast=fast, mode=mode) @@ -735,6 +932,9 @@ def format_stdin_to_stdout( sys.stdout.buffer, encoding=encoding, newline=newline, write_through=True ) if write_back == WriteBack.YES: + # Make sure there's a newline after the content + if dst and dst[-1] != "\n": + dst += "\n" f.write(dst) elif write_back in (WriteBack.DIFF, WriteBack.COLOR_DIFF): now = datetime.utcnow() @@ -748,6 +948,29 @@ def format_stdin_to_stdout( f.detach() +def check_stability_and_equivalence( + src_contents: str, dst_contents: str, *, mode: Mode +) -> None: + """Perform stability and equivalence checks. + + Raise AssertionError if source and destination contents are not + equivalent, or if a second pass of the formatter would format the + content differently. + """ + assert_equivalent(src_contents, dst_contents) + + # Forced second pass to work around optional trailing commas (becoming + # forced trailing commas on pass 2) interacting differently with optional + # parentheses. Admittedly ugly. + dst_contents_pass2 = format_str(dst_contents, mode=mode) + if dst_contents != dst_contents_pass2: + dst_contents = dst_contents_pass2 + assert_equivalent(src_contents, dst_contents, pass_num=2) + assert_stable(src_contents, dst_contents, mode=mode) + # Note: no need to explicitly call `assert_stable` if `dst_contents` was + # the same as `dst_contents_pass2`. + + def format_file_contents(src_contents: str, *, fast: bool, mode: Mode) -> FileContent: """Reformat contents of a file and return new contents. @@ -758,26 +981,123 @@ def format_file_contents(src_contents: str, *, fast: bool, mode: Mode) -> FileCo if not src_contents.strip(): raise NothingChanged - dst_contents = format_str(src_contents, mode=mode) + if mode.is_ipynb: + dst_contents = format_ipynb_string(src_contents, fast=fast, mode=mode) + else: + dst_contents = format_str(src_contents, mode=mode) if src_contents == dst_contents: raise NothingChanged - if not fast: - assert_equivalent(src_contents, dst_contents) - - # Forced second pass to work around optional trailing commas (becoming - # forced trailing commas on pass 2) interacting differently with optional - # parentheses. Admittedly ugly. - dst_contents_pass2 = format_str(dst_contents, mode=mode) - if dst_contents != dst_contents_pass2: - dst_contents = dst_contents_pass2 - assert_equivalent(src_contents, dst_contents, pass_num=2) - assert_stable(src_contents, dst_contents, mode=mode) - # Note: no need to explicitly call `assert_stable` if `dst_contents` was - # the same as `dst_contents_pass2`. + if not fast and not mode.is_ipynb: + # Jupyter notebooks will already have been checked above. + check_stability_and_equivalence(src_contents, dst_contents, mode=mode) return dst_contents +def validate_cell(src: str, mode: Mode) -> None: + """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 + ``get_ipython().system('ls')``, then it would get transformed in the same way: + + >>> TransformerManager().transform_cell("get_ipython().system('ls')") + "get_ipython().system('ls')\n" + >>> TransformerManager().transform_cell("!ls") + "get_ipython().system('ls')\n" + + Due to the impossibility of safely roundtripping in such situations, cells + containing transformed magics will be ignored. + """ + 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 | mode.python_cell_magics + ): + raise NothingChanged + + +def format_cell(src: str, *, fast: bool, mode: Mode) -> str: + """Format code in given cell of Jupyter notebook. + + General idea is: + + - if cell has trailing semicolon, remove it; + - if cell has IPython magics, mask them; + - format cell; + - reinstate IPython magics; + - reinstate trailing semicolon (if originally present); + - strip trailing newlines. + + Cells with syntax errors will not be processed, as they + could potentially be automagics or multi-line magics, which + are currently not supported. + """ + validate_cell(src, mode) + src_without_trailing_semicolon, has_trailing_semicolon = remove_trailing_semicolon( + src + ) + try: + masked_src, replacements = mask_cell(src_without_trailing_semicolon) + except SyntaxError: + raise NothingChanged from None + masked_dst = format_str(masked_src, mode=mode) + if not fast: + check_stability_and_equivalence(masked_src, masked_dst, mode=mode) + dst_without_trailing_semicolon = unmask_cell(masked_dst, replacements) + dst = put_trailing_semicolon_back( + dst_without_trailing_semicolon, has_trailing_semicolon + ) + dst = dst.rstrip("\n") + if dst == src: + raise NothingChanged from None + return dst + + +def validate_metadata(nb: MutableMapping[str, Any]) -> None: + """If notebook is marked as non-Python, don't format it. + + All notebook metadata fields are optional, see + https://nbformat.readthedocs.io/en/latest/format_description.html. So + if a notebook has empty metadata, we will try to parse it anyway. + """ + language = nb.get("metadata", {}).get("language_info", {}).get("name", None) + if language is not None and language != "python": + raise NothingChanged from None + + +def format_ipynb_string(src_contents: str, *, fast: bool, mode: Mode) -> FileContent: + """Format Jupyter notebook. + + Operate cell-by-cell, only on code cells, only for Python notebooks. + If the ``.ipynb`` originally had a trailing newline, it'll be preserved. + """ + trailing_newline = src_contents[-1] == "\n" + modified = False + nb = json.loads(src_contents) + validate_metadata(nb) + for cell in nb["cells"]: + if cell.get("cell_type", None) == "code": + try: + src = "".join(cell["source"]) + dst = format_cell(src, fast=fast, mode=mode) + except NothingChanged: + pass + else: + cell["source"] = dst.splitlines(keepends=True) + modified = True + if modified: + dst_contents = json.dumps(nb, indent=1, ensure_ascii=False) + if trailing_newline: + dst_contents = dst_contents + "\n" + return dst_contents + else: + raise NothingChanged + + def format_str(src_contents: str, *, mode: Mode) -> FileContent: """Reformat a string and return new contents. @@ -814,13 +1134,10 @@ 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) + normalize_fmt_off(src_node) - lines = LineGenerator( - mode=mode, - remove_u_prefix="unicode_literals" in future_imports - or supports_feature(versions, Feature.UNICODE_LITERALS), - ) + lines = LineGenerator(mode=mode) elt = EmptyLineTracker(is_pyi=mode.is_pyi) empty_line = Line(mode=mode) after = 0 @@ -857,7 +1174,9 @@ def decode_bytes(src: bytes) -> Tuple[FileContent, Encoding, NewLine]: return tiow.read(), encoding, newline -def get_features_used(node: Node) -> Set[Feature]: +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: @@ -867,20 +1186,34 @@ def get_features_used(node: Node) -> Set[Feature]: - 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 + if is_string_token(n): + value_head = n.value[:2] if value_head in {'f"', 'F"', "f'", "F'", "rf", "fr", "RF", "FR"}: features.add(Feature.F_STRINGS) elif n.type == token.NUMBER: - if "_" in n.value: # type: ignore + assert isinstance(n, Leaf) + if "_" in n.value: features.add(Feature.NUMERIC_UNDERSCORES) elif n.type == token.SLASH: - if n.parent and n.parent.type in {syms.typedargslist, syms.arglist}: + if n.parent and n.parent.type in { + syms.typedargslist, + syms.arglist, + syms.varargslist, + }: features.add(Feature.POS_ONLY_ARGUMENTS) elif n.type == token.COLONEQUAL: @@ -911,12 +1244,29 @@ def get_features_used(node: Node) -> Set[Feature]: if argch.type in STARS: features.add(feature) + elif ( + n.type in {syms.return_stmt, syms.yield_expr} + and len(n.children) >= 2 + and n.children[1].type == syms.testlist_star_expr + and any(child.type == syms.star_expr for child in n.children[1].children) + ): + features.add(Feature.UNPACKING_ON_FLOW) + + elif ( + n.type == syms.annassign + and len(n.children) >= 4 + and n.children[3].type == syms.testlist_star_expr + ): + features.add(Feature.ANN_ASSIGN_EXTENDED_RHS) + 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] } @@ -978,9 +1328,11 @@ def assert_equivalent(src: str, dst: str, *, pass_num: int = 1) -> None: src_ast = parse_ast(src) except Exception as exc: raise AssertionError( - "cannot use --safe with this file; failed to parse source file. AST" - f" error message: {exc}" - ) + f"cannot use --safe with this file; failed to parse source file AST: " + f"{exc}\n" + f"This could be caused by running Black with an older Python version " + f"that does not support new syntax used in your source file." + ) from exc try: dst_ast = parse_ast(dst) @@ -1029,7 +1381,7 @@ def nullcontext() -> Iterator[None]: def patch_click() -> None: - """Make Click not crash. + """Make Click not crash on Python 3.6 with LANG=C. On certain misconfigured environments, Python 3 selects the ASCII encoding as the default which restricts paths that it can access during the lifetime of the @@ -1041,16 +1393,19 @@ def patch_click() -> None: """ try: from click import core - from click import _unicodefun # type: ignore + from click import _unicodefun except ModuleNotFoundError: return for module in (core, _unicodefun): if hasattr(module, "_verify_python3_env"): - module._verify_python3_env = lambda: None + module._verify_python3_env = lambda: None # type: ignore + if hasattr(module, "_verify_python_env"): + module._verify_python_env = lambda: None # type: ignore def patched_main() -> None: + maybe_install_uvloop() freeze_support() patch_click() main()