X-Git-Url: https://git.madduck.net/etc/vim.git/blobdiff_plain/e4340f5c3edcfc2b7ee1ebad4521eeb6deb616df..4931ddd0b1f84910790bebcd86c2147d1ddcf1e1:/black.py?ds=sidebyside diff --git a/black.py b/black.py index f51b10e..18d60c0 100644 --- a/black.py +++ b/black.py @@ -2,24 +2,26 @@ import asyncio from asyncio.base_events import BaseEventLoop from concurrent.futures import Executor, ProcessPoolExecutor from datetime import datetime -from enum import Enum, Flag +from enum import Enum from functools import lru_cache, partial, wraps import io -import keyword +import itertools import logging -from multiprocessing import Manager +from multiprocessing import Manager, freeze_support import os from pathlib import Path import pickle import re import signal import sys +import tempfile import tokenize from typing import ( Any, Callable, Collection, Dict, + Generator, Generic, Iterable, Iterator, @@ -29,14 +31,13 @@ from typing import ( Sequence, Set, Tuple, - Type, TypeVar, Union, cast, ) from appdirs import user_cache_dir -from attr import dataclass, Factory +from attr import dataclass, evolve, Factory import click import toml @@ -44,13 +45,14 @@ import toml from blib2to3.pytree import Node, Leaf, type_repr from blib2to3 import pygram, pytree from blib2to3.pgen2 import driver, token +from blib2to3.pgen2.grammar import Grammar from blib2to3.pgen2.parse import ParseError -__version__ = "18.6b2" +__version__ = "19.3b0" DEFAULT_LINE_LENGTH = 88 DEFAULT_EXCLUDES = ( - r"/(\.git|\.hg|\.mypy_cache|\.tox|\.venv|_build|buck-out|build|dist)/" + r"/(\.eggs|\.git|\.hg|\.mypy_cache|\.nox|\.tox|\.venv|_build|buck-out|build|dist)/" ) DEFAULT_INCLUDES = r"\.pyi?$" CACHE_DIR = Path(user_cache_dir("black", version=__version__)) @@ -66,7 +68,7 @@ LeafID = int Priority = int Index = int LN = Union[Leaf, Node] -SplitFunc = Callable[["Line", bool], Iterator["Line"]] +SplitFunc = Callable[["Line", Collection["Feature"]], Iterator["Line"]] Timestamp = float FileSize = int CacheInfo = Tuple[Timestamp, FileSize] @@ -79,54 +81,27 @@ syms = pygram.python_symbols class NothingChanged(UserWarning): - """Raised by :func:`format_file` when reformatted code is the same as source.""" + """Raised when reformatted code is the same as source.""" class CannotSplit(Exception): - """A readable split that fits the allotted line length is impossible. + """A readable split that fits the allotted line length is impossible.""" - Raised by :func:`left_hand_split`, :func:`right_hand_split`, and - :func:`delimiter_split`. - """ - - -class FormatError(Exception): - """Base exception for `# fmt: on` and `# fmt: off` handling. - - It holds the number of bytes of the prefix consumed before the format - control comment appeared. - """ - - def __init__(self, consumed: int) -> None: - super().__init__(consumed) - self.consumed = consumed - - def trim_prefix(self, leaf: Leaf) -> None: - leaf.prefix = leaf.prefix[self.consumed :] - - def leaf_from_consumed(self, leaf: Leaf) -> Leaf: - """Returns a new Leaf from the consumed part of the prefix.""" - unformatted_prefix = leaf.prefix[: self.consumed] - return Leaf(token.NEWLINE, unformatted_prefix) - - -class FormatOn(FormatError): - """Found a comment like `# fmt: on` in the file.""" - -class FormatOff(FormatError): - """Found a comment like `# fmt: off` in the file.""" +class InvalidInput(ValueError): + """Raised when input source code fails all parse attempts.""" class WriteBack(Enum): NO = 0 YES = 1 DIFF = 2 + CHECK = 3 @classmethod def from_configuration(cls, *, check: bool, diff: bool) -> "WriteBack": if check and not diff: - return cls.NO + return cls.CHECK return cls.DIFF if diff else cls.YES @@ -137,24 +112,86 @@ class Changed(Enum): YES = 2 -class FileMode(Flag): - AUTO_DETECT = 0 - PYTHON36 = 1 - PYI = 2 - NO_STRING_NORMALIZATION = 4 +class TargetVersion(Enum): + PY27 = 2 + PY33 = 3 + PY34 = 4 + PY35 = 5 + PY36 = 6 + PY37 = 7 + PY38 = 8 + + def is_python2(self) -> bool: + return self is TargetVersion.PY27 + + +PY36_VERSIONS = {TargetVersion.PY36, TargetVersion.PY37, TargetVersion.PY38} + + +class Feature(Enum): + # All string literals are unicode + UNICODE_LITERALS = 1 + F_STRINGS = 2 + NUMERIC_UNDERSCORES = 3 + TRAILING_COMMA_IN_CALL = 4 + TRAILING_COMMA_IN_DEF = 5 + + +VERSION_TO_FEATURES: Dict[TargetVersion, Set[Feature]] = { + TargetVersion.PY27: set(), + TargetVersion.PY33: {Feature.UNICODE_LITERALS}, + TargetVersion.PY34: {Feature.UNICODE_LITERALS}, + TargetVersion.PY35: {Feature.UNICODE_LITERALS, Feature.TRAILING_COMMA_IN_CALL}, + TargetVersion.PY36: { + Feature.UNICODE_LITERALS, + Feature.F_STRINGS, + Feature.NUMERIC_UNDERSCORES, + Feature.TRAILING_COMMA_IN_CALL, + Feature.TRAILING_COMMA_IN_DEF, + }, + TargetVersion.PY37: { + Feature.UNICODE_LITERALS, + Feature.F_STRINGS, + Feature.NUMERIC_UNDERSCORES, + Feature.TRAILING_COMMA_IN_CALL, + Feature.TRAILING_COMMA_IN_DEF, + }, + TargetVersion.PY38: { + Feature.UNICODE_LITERALS, + Feature.F_STRINGS, + Feature.NUMERIC_UNDERSCORES, + Feature.TRAILING_COMMA_IN_CALL, + Feature.TRAILING_COMMA_IN_DEF, + }, +} + + +@dataclass +class FileMode: + target_versions: Set[TargetVersion] = Factory(set) + line_length: int = DEFAULT_LINE_LENGTH + string_normalization: bool = True + is_pyi: bool = False + + def get_cache_key(self) -> str: + if self.target_versions: + version_str = ",".join( + str(version.value) + for version in sorted(self.target_versions, key=lambda v: v.value) + ) + else: + version_str = "-" + parts = [ + version_str, + str(self.line_length), + str(int(self.string_normalization)), + str(int(self.is_pyi)), + ] + return ".".join(parts) - @classmethod - def from_configuration( - cls, *, py36: bool, pyi: bool, skip_string_normalization: bool - ) -> "FileMode": - mode = cls.AUTO_DETECT - if py36: - mode |= cls.PYTHON36 - if pyi: - mode |= cls.PYI - if skip_string_normalization: - mode |= cls.NO_STRING_NORMALIZATION - return mode + +def supports_feature(target_versions: Set[TargetVersion], feature: Feature) -> bool: + return all(feature in VERSION_TO_FEATURES[version] for version in target_versions) def read_pyproject_toml( @@ -178,7 +215,9 @@ def read_pyproject_toml( pyproject_toml = toml.load(value) config = pyproject_toml.get("tool", {}).get("black", {}) except (toml.TomlDecodeError, OSError) as e: - raise click.BadOptionUsage(f"Error reading configuration file: {e}", ctx) + raise click.FileError( + filename=value, hint=f"Error reading configuration file: {e}" + ) if not config: return None @@ -192,21 +231,34 @@ def read_pyproject_toml( @click.command(context_settings=dict(help_option_names=["-h", "--help"])) +@click.option("-c", "--code", type=str, help="Format the code passed in as a string.") @click.option( "-l", "--line-length", type=int, default=DEFAULT_LINE_LENGTH, - help="How many character per line to allow.", + help="How many characters per line to allow.", show_default=True, ) +@click.option( + "-t", + "--target-version", + type=click.Choice([v.name.lower() for v in TargetVersion]), + callback=lambda c, p, v: [TargetVersion[val.upper()] for val in v], + multiple=True, + help=( + "Python versions that should be supported by Black's output. [default: " + "per-file auto-detection]" + ), +) @click.option( "--py36", is_flag=True, help=( "Allow using Python 3.6-only syntax on all input files. This will put " "trailing commas in function signatures and calls also after *args and " - "**kwargs. [default: per-file auto-detection]" + "**kwargs. Deprecated; use --target-version instead. " + "[default: per-file auto-detection]" ), ) @click.option( @@ -306,7 +358,9 @@ def read_pyproject_toml( @click.pass_context def main( ctx: click.Context, + code: Optional[str], line_length: int, + target_version: List[TargetVersion], check: bool, diff: bool, fast: bool, @@ -322,11 +376,32 @@ def main( ) -> None: """The uncompromising code formatter.""" write_back = WriteBack.from_configuration(check=check, diff=diff) - mode = FileMode.from_configuration( - py36=py36, pyi=pyi, skip_string_normalization=skip_string_normalization + if target_version: + if py36: + err(f"Cannot use both --target-version and --py36") + ctx.exit(2) + else: + versions = set(target_version) + elif py36: + err( + "--py36 is deprecated and will be removed in a future version. " + "Use --target-version py36 instead." + ) + versions = PY36_VERSIONS + else: + # We'll autodetect later. + versions = set() + mode = FileMode( + target_versions=versions, + line_length=line_length, + is_pyi=pyi, + string_normalization=not skip_string_normalization, ) 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) try: include_regex = re_compile_maybe_verbose(include) except re.error: @@ -359,30 +434,16 @@ def main( if len(sources) == 1: reformat_one( src=sources.pop(), - line_length=line_length, fast=fast, write_back=write_back, mode=mode, report=report, ) else: - loop = asyncio.get_event_loop() - executor = ProcessPoolExecutor(max_workers=os.cpu_count()) - try: - loop.run_until_complete( - schedule_formatting( - sources=sources, - line_length=line_length, - fast=fast, - write_back=write_back, - mode=mode, - report=report, - loop=loop, - executor=executor, - ) - ) - finally: - shutdown(loop) + reformat_many( + sources=sources, fast=fast, write_back=write_back, mode=mode, report=report + ) + if verbose or not quiet: bang = "💥 💔 💥" if report.return_code else "✨ 🍰 ✨" out(f"All done! {bang}") @@ -391,12 +452,7 @@ def main( def reformat_one( - src: Path, - line_length: int, - fast: bool, - write_back: WriteBack, - mode: FileMode, - report: "Report", + src: Path, fast: bool, write_back: WriteBack, mode: FileMode, report: "Report" ) -> None: """Reformat a single file under `src` without spawning child processes. @@ -407,35 +463,60 @@ def reformat_one( try: changed = Changed.NO if not src.is_file() and str(src) == "-": - if format_stdin_to_stdout( - line_length=line_length, fast=fast, write_back=write_back, mode=mode - ): + if format_stdin_to_stdout(fast=fast, write_back=write_back, mode=mode): changed = Changed.YES else: cache: Cache = {} if write_back != WriteBack.DIFF: - cache = read_cache(line_length, mode) + cache = read_cache(mode) res_src = src.resolve() if res_src in cache and cache[res_src] == get_cache_info(res_src): changed = Changed.CACHED if changed is not Changed.CACHED and format_file_in_place( - src, - line_length=line_length, - fast=fast, - write_back=write_back, - mode=mode, + src, fast=fast, write_back=write_back, mode=mode ): changed = Changed.YES - if write_back == WriteBack.YES and changed is not Changed.NO: - write_cache(cache, [src], line_length, mode) + if (write_back is WriteBack.YES and changed is not Changed.CACHED) or ( + write_back is WriteBack.CHECK and changed is Changed.NO + ): + write_cache(cache, [src], mode) report.done(src, changed) except Exception as exc: report.failed(src, str(exc)) +def reformat_many( + sources: Set[Path], + fast: bool, + write_back: WriteBack, + mode: FileMode, + report: "Report", +) -> None: + """Reformat multiple files using a ProcessPoolExecutor.""" + loop = asyncio.get_event_loop() + worker_count = os.cpu_count() + if sys.platform == "win32": + # Work around https://bugs.python.org/issue26903 + worker_count = min(worker_count, 61) + executor = ProcessPoolExecutor(max_workers=worker_count) + try: + loop.run_until_complete( + schedule_formatting( + sources=sources, + fast=fast, + write_back=write_back, + mode=mode, + report=report, + loop=loop, + executor=executor, + ) + ) + finally: + shutdown(loop) + + async def schedule_formatting( sources: Set[Path], - line_length: int, fast: bool, write_back: WriteBack, mode: FileMode, @@ -452,79 +533,80 @@ async def schedule_formatting( """ cache: Cache = {} if write_back != WriteBack.DIFF: - cache = read_cache(line_length, mode) + cache = read_cache(mode) sources, cached = filter_cached(cache, sources) for src in sorted(cached): report.done(src, Changed.CACHED) + if not sources: + return + cancelled = [] - formatted = [] - if sources: - lock = None - if write_back == WriteBack.DIFF: - # For diff output, we need locks to ensure we don't interleave output - # from different processes. - manager = Manager() - lock = manager.Lock() - tasks = { + sources_to_cache = [] + lock = None + if write_back == WriteBack.DIFF: + # For diff output, we need locks to ensure we don't interleave output + # from different processes. + manager = Manager() + lock = manager.Lock() + tasks = { + asyncio.ensure_future( loop.run_in_executor( - executor, - format_file_in_place, - src, - line_length, - fast, - write_back, - mode, - lock, - ): src - for src in sorted(sources) - } - pending: Iterable[asyncio.Task] = tasks.keys() - try: - loop.add_signal_handler(signal.SIGINT, cancel, pending) - loop.add_signal_handler(signal.SIGTERM, cancel, pending) - except NotImplementedError: - # There are no good alternatives for these on Windows - pass - while pending: - done, _ = await asyncio.wait(pending, return_when=asyncio.FIRST_COMPLETED) - for task in done: - src = tasks.pop(task) - if task.cancelled(): - cancelled.append(task) - elif task.exception(): - report.failed(src, str(task.exception())) - else: - formatted.append(src) - report.done(src, Changed.YES if task.result() else Changed.NO) + executor, format_file_in_place, src, fast, mode, write_back, lock + ) + ): src + for src in sorted(sources) + } + pending: Iterable[asyncio.Future] = tasks.keys() + try: + loop.add_signal_handler(signal.SIGINT, cancel, pending) + loop.add_signal_handler(signal.SIGTERM, cancel, pending) + except NotImplementedError: + # There are no good alternatives for these on Windows. + pass + while pending: + done, _ = await asyncio.wait(pending, return_when=asyncio.FIRST_COMPLETED) + for task in done: + src = tasks.pop(task) + if task.cancelled(): + cancelled.append(task) + elif task.exception(): + report.failed(src, str(task.exception())) + else: + changed = Changed.YES if task.result() else Changed.NO + # If the file was written back or was successfully checked as + # well-formatted, store this information in the cache. + if write_back is WriteBack.YES or ( + write_back is WriteBack.CHECK and changed is Changed.NO + ): + sources_to_cache.append(src) + report.done(src, changed) if cancelled: await asyncio.gather(*cancelled, loop=loop, return_exceptions=True) - if write_back == WriteBack.YES and formatted: - write_cache(cache, formatted, line_length, mode) + if sources_to_cache: + write_cache(cache, sources_to_cache, mode) def format_file_in_place( src: Path, - line_length: int, fast: bool, + mode: FileMode, write_back: WriteBack = WriteBack.NO, - mode: FileMode = FileMode.AUTO_DETECT, lock: Any = None, # multiprocessing.Manager().Lock() is some crazy proxy ) -> bool: """Format file under `src` path. Return True if changed. - If `write_back` is True, write reformatted code back to stdout. + If `write_back` is DIFF, write a diff to stdout. If it is YES, write reformatted + code to the file. `line_length` and `fast` options are passed to :func:`format_file_contents`. """ if src.suffix == ".pyi": - mode |= FileMode.PYI + mode = evolve(mode, is_pyi=True) then = datetime.utcfromtimestamp(src.stat().st_mtime) with open(src, "rb") as buf: src_contents, encoding, newline = decode_bytes(buf.read()) try: - dst_contents = format_file_contents( - src_contents, line_length=line_length, fast=fast, mode=mode - ) + dst_contents = format_file_contents(src_contents, fast=fast, mode=mode) except NothingChanged: return False @@ -554,22 +636,19 @@ def format_file_in_place( def format_stdin_to_stdout( - line_length: int, - fast: bool, - write_back: WriteBack = WriteBack.NO, - mode: FileMode = FileMode.AUTO_DETECT, + fast: bool, *, write_back: WriteBack = WriteBack.NO, mode: FileMode ) -> bool: """Format file on stdin. Return True if changed. - If `write_back` is True, write reformatted code back to stdout. - `line_length`, `fast`, `is_pyi`, and `force_py36` arguments are passed to + 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()) dst = src try: - dst = format_file_contents(src, line_length=line_length, fast=fast, mode=mode) + dst = format_file_contents(src, fast=fast, mode=mode) return True except NothingChanged: @@ -590,11 +669,7 @@ def format_stdin_to_stdout( def format_file_contents( - src_contents: str, - *, - line_length: int, - fast: bool, - mode: FileMode = FileMode.AUTO_DETECT, + src_contents: str, *, fast: bool, mode: FileMode ) -> FileContent: """Reformat contents a file and return new contents. @@ -605,44 +680,52 @@ def format_file_contents( if src_contents.strip() == "": raise NothingChanged - dst_contents = format_str(src_contents, line_length=line_length, mode=mode) + dst_contents = format_str(src_contents, mode=mode) if src_contents == dst_contents: raise NothingChanged if not fast: assert_equivalent(src_contents, dst_contents) - assert_stable(src_contents, dst_contents, line_length=line_length, mode=mode) + assert_stable(src_contents, dst_contents, mode=mode) return dst_contents -def format_str( - src_contents: str, line_length: int, *, mode: FileMode = FileMode.AUTO_DETECT -) -> FileContent: +def format_str(src_contents: str, *, mode: FileMode) -> FileContent: """Reformat a string and return new contents. `line_length` determines how many characters per line are allowed. """ - src_node = lib2to3_parse(src_contents) + src_node = lib2to3_parse(src_contents.lstrip(), mode.target_versions) dst_contents = "" future_imports = get_future_imports(src_node) - is_pyi = bool(mode & FileMode.PYI) - py36 = bool(mode & FileMode.PYTHON36) or is_python36(src_node) - normalize_strings = not bool(mode & FileMode.NO_STRING_NORMALIZATION) + if mode.target_versions: + versions = mode.target_versions + else: + versions = detect_target_versions(src_node) + normalize_fmt_off(src_node) lines = LineGenerator( - remove_u_prefix=py36 or "unicode_literals" in future_imports, - is_pyi=is_pyi, - normalize_strings=normalize_strings, + remove_u_prefix="unicode_literals" in future_imports + or supports_feature(versions, Feature.UNICODE_LITERALS), + is_pyi=mode.is_pyi, + normalize_strings=mode.string_normalization, ) - elt = EmptyLineTracker(is_pyi=is_pyi) + elt = EmptyLineTracker(is_pyi=mode.is_pyi) empty_line = Line() after = 0 + split_line_features = { + feature + for feature in {Feature.TRAILING_COMMA_IN_CALL, Feature.TRAILING_COMMA_IN_DEF} + if supports_feature(versions, feature) + } for current_line in lines.visit(src_node): for _ in range(after): dst_contents += str(empty_line) before, after = elt.maybe_empty_lines(current_line) for _ in range(before): dst_contents += str(empty_line) - for line in split_line(current_line, line_length=line_length, py36=py36): + for line in split_line( + current_line, line_length=mode.line_length, features=split_line_features + ): dst_contents += str(line) return dst_contents @@ -664,19 +747,28 @@ def decode_bytes(src: bytes) -> Tuple[FileContent, Encoding, NewLine]: return tiow.read(), encoding, newline -GRAMMARS = [ - pygram.python_grammar_no_print_statement_no_exec_statement, - pygram.python_grammar_no_print_statement, - pygram.python_grammar, -] +def get_grammars(target_versions: Set[TargetVersion]) -> List[Grammar]: + if not target_versions: + # No target_version specified, so try all grammars. + return [ + pygram.python_grammar_no_print_statement_no_exec_statement, + pygram.python_grammar_no_print_statement, + pygram.python_grammar, + ] + elif all(version.is_python2() for version in target_versions): + # Python 2-only code, so try Python 2 grammars. + return [pygram.python_grammar_no_print_statement, pygram.python_grammar] + else: + # Python 3-compatible code, so only try Python 3 grammar. + return [pygram.python_grammar_no_print_statement_no_exec_statement] -def lib2to3_parse(src_txt: str) -> Node: +def lib2to3_parse(src_txt: str, target_versions: Iterable[TargetVersion] = ()) -> Node: """Given a string with source, return the lib2to3 Node.""" - grammar = pygram.python_grammar_no_print_statement if src_txt[-1:] != "\n": src_txt += "\n" - for grammar in GRAMMARS: + + for grammar in get_grammars(set(target_versions)): drv = driver.Driver(grammar, pytree.convert) try: result = drv.parse_string(src_txt, True) @@ -689,7 +781,7 @@ def lib2to3_parse(src_txt: str) -> Node: faulty_line = lines[lineno - 1] except IndexError: faulty_line = "" - exc = ValueError(f"Cannot parse: {lineno}:{column}: {faulty_line}") + exc = InvalidInput(f"Cannot parse: {lineno}:{column}: {faulty_line}") else: raise exc from None @@ -758,18 +850,18 @@ class DebugVisitor(Visitor[T]): out(f" {node.value!r}", fg="blue", bold=False) @classmethod - def show(cls, code: str) -> None: + def show(cls, code: Union[str, Leaf, Node]) -> None: """Pretty-print the lib2to3 AST of a given string of `code`. Convenience method for debugging. """ v: DebugVisitor[None] = DebugVisitor() - list(v.visit(lib2to3_parse(code))) + if isinstance(code, str): + code = lib2to3_parse(code) + list(v.visit(code)) -KEYWORDS = set(keyword.kwlist) WHITESPACE = {token.DEDENT, token.INDENT, token.NEWLINE} -FLOW_CONTROL = {"return", "raise", "break", "continue"} STATEMENT = { syms.if_stmt, syms.while_stmt, @@ -781,6 +873,7 @@ STATEMENT = { syms.classdef, } STANDALONE_COMMENT = 153 +token.tok_name[STANDALONE_COMMENT] = "STANDALONE_COMMENT" LOGIC_OPERATORS = {"and", "or"} COMPARATORS = { token.LESS, @@ -887,8 +980,8 @@ class BracketTracker: bracket_match: Dict[Tuple[Depth, NodeType], Leaf] = Factory(dict) delimiters: Dict[LeafID, Priority] = Factory(dict) previous: Optional[Leaf] = None - _for_loop_variable: int = 0 - _lambda_arguments: int = 0 + _for_loop_depths: List[int] = Factory(list) + _lambda_argument_depths: List[int] = Factory(list) def mark(self, leaf: Leaf) -> None: """Mark `leaf` with bracket-related metadata. Keep track of delimiters. @@ -961,16 +1054,21 @@ class BracketTracker: """ if leaf.type == token.NAME and leaf.value == "for": self.depth += 1 - self._for_loop_variable += 1 + self._for_loop_depths.append(self.depth) return True return False def maybe_decrement_after_for_loop_variable(self, leaf: Leaf) -> bool: """See `maybe_increment_for_loop_variable` above for explanation.""" - if self._for_loop_variable and leaf.type == token.NAME and leaf.value == "in": + if ( + self._for_loop_depths + and self._for_loop_depths[-1] == self.depth + and leaf.type == token.NAME + and leaf.value == "in" + ): self.depth -= 1 - self._for_loop_variable -= 1 + self._for_loop_depths.pop() return True return False @@ -983,16 +1081,20 @@ class BracketTracker: """ if leaf.type == token.NAME and leaf.value == "lambda": self.depth += 1 - self._lambda_arguments += 1 + self._lambda_argument_depths.append(self.depth) return True return False def maybe_decrement_after_lambda_arguments(self, leaf: Leaf) -> bool: """See `maybe_increment_lambda_arguments` above for explanation.""" - if self._lambda_arguments and leaf.type == token.COLON: + if ( + self._lambda_argument_depths + and self._lambda_argument_depths[-1] == self.depth + and leaf.type == token.COLON + ): self.depth -= 1 - self._lambda_arguments -= 1 + self._lambda_argument_depths.pop() return True return False @@ -1008,7 +1110,7 @@ class Line: depth: int = 0 leaves: List[Leaf] = Factory(list) - comments: List[Tuple[Index, Leaf]] = Factory(list) + comments: Dict[LeafID, List[Leaf]] = Factory(dict) # keys ordered like `leaves` bracket_tracker: BracketTracker = Factory(BracketTracker) inside_brackets: bool = False should_explode: bool = False @@ -1139,6 +1241,29 @@ class Line: if leaf.type == STANDALONE_COMMENT: if leaf.bracket_depth <= depth_limit: return True + return False + + def contains_inner_type_comments(self) -> bool: + ignored_ids = set() + try: + last_leaf = self.leaves[-1] + ignored_ids.add(id(last_leaf)) + if last_leaf.type == token.COMMA: + # When trailing commas are inserted by Black for consistency, comments + # after the previous last element are not moved (they don't have to, + # rendering will still be correct). So we ignore trailing commas. + last_leaf = self.leaves[-2] + ignored_ids.add(id(last_leaf)) + except IndexError: + return False + + for leaf_id, comments in self.comments.items(): + if leaf_id in ignored_ids: + continue + + for comment in comments: + if is_type_comment(comment): + return True return False @@ -1174,7 +1299,7 @@ class Line: self.remove_trailing_comma() return True - # Otheriwsse, if the trailing one is the only one, we might mistakenly + # Otherwise, if the trailing one is the only one, we might mistakenly # change a tuple into a different type by removing the comma. depth = closing.bracket_depth + 1 commas = 0 @@ -1215,44 +1340,25 @@ class Line: if comment.type != token.COMMENT: return False - after = len(self.leaves) - 1 - if after == -1: + if not self.leaves: comment.type = STANDALONE_COMMENT comment.prefix = "" return False - else: - self.comments.append((after, comment)) - return True - - def comments_after(self, leaf: Leaf, _index: int = -1) -> Iterator[Leaf]: - """Generate comments that should appear directly after `leaf`. - - Provide a non-negative leaf `_index` to speed up the function. - """ - if not self.comments: - return - - if _index == -1: - for _index, _leaf in enumerate(self.leaves): - if leaf is _leaf: - break - - else: - return + self.comments.setdefault(id(self.leaves[-1]), []).append(comment) + return True - for index, comment_after in self.comments: - if _index == index: - yield comment_after + def comments_after(self, leaf: Leaf) -> List[Leaf]: + """Generate comments that should appear directly after `leaf`.""" + return self.comments.get(id(leaf), []) def remove_trailing_comma(self) -> None: """Remove the trailing comma and moves the comments attached to it.""" - comma_index = len(self.leaves) - 1 - for i in range(len(self.comments)): - comment_index, comment = self.comments[i] - if comment_index == comma_index: - self.comments[i] = (comma_index - 1, comment) - self.leaves.pop() + trailing_comma = self.leaves.pop() + trailing_comma_comments = self.comments.pop(id(trailing_comma), []) + self.comments.setdefault(id(self.leaves[-1]), []).extend( + trailing_comma_comments + ) def is_complex_subscript(self, leaf: Leaf) -> bool: """Return True iff `leaf` is part of a slice with non-trivial exprs.""" @@ -1283,7 +1389,7 @@ class Line: res = f"{first.prefix}{indent}{first.value}" for leaf in leaves: res += str(leaf) - for _, comment in self.comments: + for comment in itertools.chain.from_iterable(self.comments.values()): res += str(comment) return res + "\n" @@ -1292,55 +1398,6 @@ class Line: return bool(self.leaves or self.comments) -class UnformattedLines(Line): - """Just like :class:`Line` but stores lines which aren't reformatted.""" - - def append(self, leaf: Leaf, preformatted: bool = True) -> None: - """Just add a new `leaf` to the end of the lines. - - The `preformatted` argument is ignored. - - Keeps track of indentation `depth`, which is useful when the user - says `# fmt: on`. Otherwise, doesn't do anything with the `leaf`. - """ - try: - list(generate_comments(leaf)) - except FormatOn as f_on: - self.leaves.append(f_on.leaf_from_consumed(leaf)) - raise - - self.leaves.append(leaf) - if leaf.type == token.INDENT: - self.depth += 1 - elif leaf.type == token.DEDENT: - self.depth -= 1 - - def __str__(self) -> str: - """Render unformatted lines from leaves which were added with `append()`. - - `depth` is not used for indentation in this case. - """ - if not self: - return "\n" - - res = "" - for leaf in self.leaves: - res += str(leaf) - return res - - def append_comment(self, comment: Leaf) -> bool: - """Not implemented in this class. Raises `NotImplementedError`.""" - raise NotImplementedError("Unformatted lines don't store comments separately.") - - def maybe_remove_trailing_comma(self, closing: Leaf) -> bool: - """Does nothing and returns False.""" - return False - - def maybe_increment_for_loop_variable(self, leaf: Leaf) -> bool: - """Does nothing and returns False.""" - return False - - @dataclass class EmptyLineTracker: """Provides a stateful method that returns the number of potential extra @@ -1362,9 +1419,6 @@ class EmptyLineTracker: This is for separating `def`, `async def` and `class` with extra empty lines (two on module-level). """ - if isinstance(current_line, UnformattedLines): - return 0, 0 - before, after = self._maybe_empty_lines(current_line) before -= self.previous_after self.previous_after = after @@ -1439,7 +1493,7 @@ class EmptyLineTracker: newlines = 1 elif current_line.is_class or self.previous_line.is_class: if current_line.is_stub_class and self.previous_line.is_stub_class: - # No blank line between classes with an emty body + # No blank line between classes with an empty body newlines = 0 else: newlines = 1 @@ -1468,7 +1522,7 @@ class LineGenerator(Visitor[Line]): current_line: Line = Factory(Line) remove_u_prefix: bool = False - def line(self, indent: int = 0, type: Type[Line] = Line) -> Iterator[Line]: + def line(self, indent: int = 0) -> Iterator[Line]: """Generate a line. If the line is empty, only emit if it makes sense. @@ -1477,67 +1531,41 @@ class LineGenerator(Visitor[Line]): If any lines were generated, set up a new current_line. """ if not self.current_line: - if self.current_line.__class__ == type: - self.current_line.depth += indent - else: - self.current_line = type(depth=self.current_line.depth + indent) + self.current_line.depth += indent return # Line is empty, don't emit. Creating a new one unnecessary. complete_line = self.current_line - self.current_line = type(depth=complete_line.depth + indent) + self.current_line = Line(depth=complete_line.depth + indent) yield complete_line - def visit(self, node: LN) -> Iterator[Line]: - """Main method to visit `node` and its children. - - Yields :class:`Line` objects. - """ - if isinstance(self.current_line, UnformattedLines): - # File contained `# fmt: off` - yield from self.visit_unformatted(node) - - else: - yield from super().visit(node) - def visit_default(self, node: LN) -> Iterator[Line]: """Default `visit_*()` implementation. Recurses to children of `node`.""" if isinstance(node, Leaf): any_open_brackets = self.current_line.bracket_tracker.any_open_brackets() - try: - for comment in generate_comments(node): - if any_open_brackets: - # any comment within brackets is subject to splitting - self.current_line.append(comment) - elif comment.type == token.COMMENT: - # regular trailing comment - self.current_line.append(comment) - yield from self.line() - - else: - # regular standalone comment - yield from self.line() - - self.current_line.append(comment) - yield from self.line() - - except FormatOff as f_off: - f_off.trim_prefix(node) - yield from self.line(type=UnformattedLines) - yield from self.visit(node) + for comment in generate_comments(node): + if any_open_brackets: + # any comment within brackets is subject to splitting + self.current_line.append(comment) + elif comment.type == token.COMMENT: + # regular trailing comment + self.current_line.append(comment) + yield from self.line() - except FormatOn as f_on: - # This only happens here if somebody says "fmt: on" multiple - # times in a row. - f_on.trim_prefix(node) - yield from self.visit_default(node) - - else: - normalize_prefix(node, inside_brackets=any_open_brackets) - if self.normalize_strings and node.type == token.STRING: - normalize_string_prefix(node, remove_u_prefix=self.remove_u_prefix) - normalize_string_quotes(node) - if node.type not in WHITESPACE: - self.current_line.append(node) + else: + # regular standalone comment + yield from self.line() + + self.current_line.append(comment) + yield from self.line() + + normalize_prefix(node, inside_brackets=any_open_brackets) + if self.normalize_strings and node.type == token.STRING: + normalize_string_prefix(node, remove_u_prefix=self.remove_u_prefix) + normalize_string_quotes(node) + if node.type == token.NUMBER: + normalize_numeric_literal(node) + if node.type not in WHITESPACE: + self.current_line.append(node) yield from super().visit_default(node) def visit_INDENT(self, node: Node) -> Iterator[Line]: @@ -1634,23 +1662,10 @@ class LineGenerator(Visitor[Line]): yield from self.visit_default(leaf) yield from self.line() - def visit_unformatted(self, node: LN) -> Iterator[Line]: - """Used when file contained a `# fmt: off`.""" - if isinstance(node, Node): - for child in node.children: - yield from self.visit(child) - - else: - try: - self.current_line.append(node) - except FormatOn as f_on: - f_on.trim_prefix(node) - yield from self.line() - yield from self.visit(node) - - if node.type == token.ENDMARKER: - # somebody decided not to put a final `# fmt: on` - yield from self.line() + def visit_STANDALONE_COMMENT(self, leaf: Leaf) -> Iterator[Line]: + if not self.current_line.bracket_tracker.any_open_brackets(): + yield from self.line() + yield from self.visit_default(leaf) def __attrs_post_init__(self) -> None: """You are in a twisty little maze of passages.""" @@ -1672,6 +1687,7 @@ class LineGenerator(Visitor[Line]): self.visit_expr_stmt = partial(v, keywords=Ø, parens=ASSIGNMENTS) self.visit_return_stmt = partial(v, keywords={"return"}, parens={"return"}) self.visit_import_from = partial(v, keywords=Ø, parens={"import"}) + self.visit_del_stmt = partial(v, keywords=Ø, parens={"del"}) self.visit_async_funcdef = self.visit_async_stmt self.visit_decorated = self.visit_decorators @@ -1684,7 +1700,7 @@ BRACKETS = OPENING_BRACKETS | CLOSING_BRACKETS ALWAYS_NO_SPACE = CLOSING_BRACKETS | {token.COMMA, STANDALONE_COMMENT} -def whitespace(leaf: Leaf, *, complex_subscript: bool) -> str: # noqa C901 +def whitespace(leaf: Leaf, *, complex_subscript: bool) -> str: # noqa: C901 """Return whitespace prefix if needed for the given `leaf`. `complex_subscript` signals whether the given leaf is part of a subscription @@ -1940,7 +1956,32 @@ def child_towards(ancestor: Node, descendant: LN) -> Optional[LN]: return node -def is_split_after_delimiter(leaf: Leaf, previous: Leaf = None) -> int: +def container_of(leaf: Leaf) -> LN: + """Return `leaf` or one of its ancestors that is the topmost container of it. + + By "container" we mean a node where `leaf` is the very first child. + """ + same_prefix = leaf.prefix + container: LN = leaf + while container: + parent = container.parent + if parent is None: + break + + if parent.children[0].prefix != same_prefix: + break + + if parent.type == syms.file_input: + break + + if parent.prev_sibling is not None and parent.prev_sibling.type in BRACKETS: + break + + container = parent + return container + + +def is_split_after_delimiter(leaf: Leaf, previous: Optional[Leaf] = None) -> int: """Return the priority of the `leaf` delimiter, given a line break after it. The delimiter priorities returned here are from those delimiters that would @@ -1954,8 +1995,8 @@ def is_split_after_delimiter(leaf: Leaf, previous: Leaf = None) -> int: return 0 -def is_split_before_delimiter(leaf: Leaf, previous: Leaf = None) -> int: - """Return the priority of the `leaf` delimiter, given a line before after it. +def is_split_before_delimiter(leaf: Leaf, previous: Optional[Leaf] = None) -> int: + """Return the priority of the `leaf` delimiter, given a line break before it. The delimiter priorities returned here are from those delimiters that would cause a line break before themselves. @@ -1992,15 +2033,20 @@ def is_split_before_delimiter(leaf: Leaf, previous: Leaf = None) -> int: ): return STRING_PRIORITY - if leaf.type != token.NAME: + if leaf.type not in {token.NAME, token.ASYNC}: return 0 if ( leaf.value == "for" and leaf.parent and leaf.parent.type in {syms.comp_for, syms.old_comp_for} + or leaf.type == token.ASYNC ): - return COMPREHENSION_PRIORITY + if ( + not isinstance(leaf.prev_sibling, Leaf) + or leaf.prev_sibling.value != "async" + ): + return COMPREHENSION_PRIORITY if ( leaf.value == "if" @@ -2070,20 +2116,20 @@ def generate_comments(leaf: LN) -> Iterator[Leaf]: """ for pc in list_comments(leaf.prefix, is_endmarker=leaf.type == token.ENDMARKER): yield Leaf(pc.type, pc.value, prefix="\n" * pc.newlines) - if pc.value in FMT_ON: - raise FormatOn(pc.consumed) - - if pc.value in FMT_OFF: - if pc.type == STANDALONE_COMMENT: - raise FormatOff(pc.consumed) - - prev = preceding_leaf(leaf) - if not prev or prev.type in WHITESPACE: # standalone comment in disguise - raise FormatOff(pc.consumed) @dataclass class ProtoComment: + """Describes a piece of syntax that is a comment. + + It's not a :class:`blib2to3.pytree.Leaf` so that: + + * it can be cached (`Leaf` objects should not be reused more than once as + they store their lineno, column, prefix, and parent information); + * `newlines` and `consumed` fields are kept separate from the `value`. This + simplifies handling of special marker comments like ``# fmt: off/on``. + """ + type: int # token.COMMENT or STANDALONE_COMMENT value: str # content of the comment newlines: int # how many newlines before the comment @@ -2091,7 +2137,8 @@ class ProtoComment: @lru_cache(maxsize=4096) -def list_comments(prefix: str, is_endmarker: bool) -> List[ProtoComment]: +def list_comments(prefix: str, *, is_endmarker: bool) -> List[ProtoComment]: + """Return a list of :class:`ProtoComment` objects parsed from the given `prefix`.""" result: List[ProtoComment] = [] if not prefix or "#" not in prefix: return result @@ -2123,8 +2170,8 @@ def list_comments(prefix: str, is_endmarker: bool) -> List[ProtoComment]: def make_comment(content: str) -> str: """Return a consistently formatted comment from the given `content` string. - All comments (except for "##", "#!", "#:") should have a single space between - the hash sign and the content. + All comments (except for "##", "#!", "#:", '#'", "#%%") should have a single + space between the hash sign and the content. If `content` didn't start with a hash sign, one is provided. """ @@ -2134,13 +2181,16 @@ def make_comment(content: str) -> str: if content[0] == "#": content = content[1:] - if content and content[0] not in " !:#": + if content and content[0] not in " !:#'%": content = " " + content return "#" + content def split_line( - line: Line, line_length: int, inner: bool = False, py36: bool = False + line: Line, + line_length: int, + inner: bool = False, + features: Collection[Feature] = (), ) -> Iterator[Line]: """Split a `line` into potentially many lines. @@ -2149,16 +2199,18 @@ def split_line( current `line`, possibly transitively. This means we can fallback to splitting by delimiters if the LHS/RHS don't yield any results. - If `py36` is True, splitting may generate syntax that is only compatible - with Python 3.6 and later. + `features` are syntactical features that may be used in the output. """ - if isinstance(line, UnformattedLines) or line.is_comment: + if line.is_comment: yield line return line_str = str(line).strip("\n") - if not line.should_explode and is_line_short_enough( - line, line_length=line_length, line_str=line_str + + if ( + not line.contains_inner_type_comments() + and not line.should_explode + and is_line_short_enough(line, line_length=line_length, line_str=line_str) ): yield line return @@ -2168,9 +2220,9 @@ def split_line( split_funcs = [left_hand_split] else: - def rhs(line: Line, py36: bool = False) -> Iterator[Line]: + def rhs(line: Line, features: Collection[Feature]) -> Iterator[Line]: for omit in generate_trailers_to_omit(line, line_length): - lines = list(right_hand_split(line, line_length, py36, omit=omit)) + lines = list(right_hand_split(line, line_length, features, omit=omit)) if is_line_short_enough(lines[0], line_length=line_length): yield from lines return @@ -2178,7 +2230,7 @@ def split_line( # All splits failed, best effort split with no omits. # This mostly happens to multiline strings that are by definition # reported as not fitting a single line. - yield from right_hand_split(line, py36) + yield from right_hand_split(line, line_length, features=features) if line.inside_brackets: split_funcs = [delimiter_split, standalone_comment_split, rhs] @@ -2190,14 +2242,16 @@ def split_line( # split altogether. result: List[Line] = [] try: - for l in split_func(line, py36): + for l in split_func(line, features): if str(l).strip("\n") == line_str: raise CannotSplit("Split function returned an unchanged result") result.extend( - split_line(l, line_length=line_length, inner=True, py36=py36) + split_line( + l, line_length=line_length, inner=True, features=features + ) ) - except CannotSplit as cs: + except CannotSplit: continue else: @@ -2208,16 +2262,13 @@ def split_line( yield line -def left_hand_split(line: Line, py36: bool = False) -> Iterator[Line]: +def left_hand_split(line: Line, features: Collection[Feature] = ()) -> Iterator[Line]: """Split line into many lines, starting with the first matching bracket pair. Note: this usually looks weird, only use this for function definitions. Prefer RHS otherwise. This is why this function is not symmetrical with :func:`right_hand_split` which also handles optional parentheses. """ - head = Line(depth=line.depth) - body = Line(depth=line.depth + 1, inside_brackets=True) - tail = Line(depth=line.depth) tail_leaves: List[Leaf] = [] body_leaves: List[Leaf] = [] head_leaves: List[Leaf] = [] @@ -2235,15 +2286,12 @@ def left_hand_split(line: Line, py36: bool = False) -> Iterator[Line]: if leaf.type in OPENING_BRACKETS: matching_bracket = leaf current_leaves = body_leaves - # Since body is a new indent level, remove spurious leading whitespace. - if body_leaves: - normalize_prefix(body_leaves[0], inside_brackets=True) - # Build the new lines. - for result, leaves in (head, head_leaves), (body, body_leaves), (tail, tail_leaves): - for leaf in leaves: - result.append(leaf, preformatted=True) - for comment_after in line.comments_after(leaf): - result.append(comment_after, preformatted=True) + if not matching_bracket: + raise CannotSplit("No brackets found") + + head = bracket_split_build_line(head_leaves, line, matching_bracket) + body = bracket_split_build_line(body_leaves, line, matching_bracket, is_body=True) + tail = bracket_split_build_line(tail_leaves, line, matching_bracket) bracket_split_succeeded_or_raise(head, body, tail) for result in (head, body, tail): if result: @@ -2251,7 +2299,10 @@ def left_hand_split(line: Line, py36: bool = False) -> Iterator[Line]: def right_hand_split( - line: Line, line_length: int, py36: bool = False, omit: Collection[LeafID] = () + line: Line, + line_length: int, + features: Collection[Feature] = (), + omit: Collection[LeafID] = (), ) -> Iterator[Line]: """Split line into many lines, starting with the last matching bracket pair. @@ -2261,9 +2312,6 @@ def right_hand_split( Note: running this function modifies `bracket_depth` on the leaves of `line`. """ - head = Line(depth=line.depth) - body = Line(depth=line.depth + 1, inside_brackets=True) - tail = Line(depth=line.depth) tail_leaves: List[Leaf] = [] body_leaves: List[Leaf] = [] head_leaves: List[Leaf] = [] @@ -2280,25 +2328,18 @@ def right_hand_split( opening_bracket = leaf.opening_bracket closing_bracket = leaf current_leaves = body_leaves - tail_leaves.reverse() - body_leaves.reverse() - head_leaves.reverse() - # Since body is a new indent level, remove spurious leading whitespace. - if body_leaves: - normalize_prefix(body_leaves[0], inside_brackets=True) - if not head_leaves: - # No `head` means the split failed. Either `tail` has all content or + if not (opening_bracket and closing_bracket and head_leaves): + # If there is no opening or closing_bracket that means the split failed and + # all content is in the tail. Otherwise, if `head_leaves` are empty, it means # the matching `opening_bracket` wasn't available on `line` anymore. raise CannotSplit("No brackets found") - # Build the new lines. - for result, leaves in (head, head_leaves), (body, body_leaves), (tail, tail_leaves): - for leaf in leaves: - result.append(leaf, preformatted=True) - for comment_after in line.comments_after(leaf): - result.append(comment_after, preformatted=True) - assert opening_bracket and closing_bracket - body.should_explode = should_explode(body, opening_bracket) + tail_leaves.reverse() + body_leaves.reverse() + head_leaves.reverse() + head = bracket_split_build_line(head_leaves, line, opening_bracket) + body = bracket_split_build_line(body_leaves, line, opening_bracket, is_body=True) + tail = bracket_split_build_line(tail_leaves, line, opening_bracket) bracket_split_succeeded_or_raise(head, body, tail) if ( # the body shouldn't be exploded @@ -2319,7 +2360,7 @@ def right_hand_split( ): omit = {id(closing_bracket), *omit} try: - yield from right_hand_split(line, line_length, py36=py36, omit=omit) + yield from right_hand_split(line, line_length, features=features, omit=omit) return except CannotSplit: @@ -2372,6 +2413,42 @@ def bracket_split_succeeded_or_raise(head: Line, body: Line, tail: Line) -> None ) +def bracket_split_build_line( + leaves: List[Leaf], original: Line, opening_bracket: Leaf, *, is_body: bool = False +) -> Line: + """Return a new line with given `leaves` and respective comments from `original`. + + If `is_body` is True, the result line is one-indented inside brackets and as such + has its first leaf's prefix normalized and a trailing comma added when expected. + """ + result = Line(depth=original.depth) + if is_body: + result.inside_brackets = True + result.depth += 1 + if leaves: + # Since body is a new indent level, remove spurious leading whitespace. + normalize_prefix(leaves[0], inside_brackets=True) + # Ensure a trailing comma for imports, but be careful not to add one after + # any comments. + if original.is_import: + for i in range(len(leaves) - 1, -1, -1): + if leaves[i].type == STANDALONE_COMMENT: + continue + elif leaves[i].type == token.COMMA: + break + else: + leaves.insert(i + 1, Leaf(token.COMMA, ",")) + break + # Populate the line + for leaf in leaves: + result.append(leaf, preformatted=True) + for comment_after in original.comments_after(leaf): + result.append(comment_after, preformatted=True) + if is_body: + result.should_explode = should_explode(result, opening_bracket) + return result + + def dont_increase_indentation(split_func: SplitFunc) -> SplitFunc: """Normalize prefix of the first leaf in every line returned by `split_func`. @@ -2379,8 +2456,8 @@ def dont_increase_indentation(split_func: SplitFunc) -> SplitFunc: """ @wraps(split_func) - def split_wrapper(line: Line, py36: bool = False) -> Iterator[Line]: - for l in split_func(line, py36): + def split_wrapper(line: Line, features: Collection[Feature] = ()) -> Iterator[Line]: + for l in split_func(line, features): normalize_prefix(l.leaves[0], inside_brackets=True) yield l @@ -2388,11 +2465,11 @@ def dont_increase_indentation(split_func: SplitFunc) -> SplitFunc: @dont_increase_indentation -def delimiter_split(line: Line, py36: bool = False) -> Iterator[Line]: +def delimiter_split(line: Line, features: Collection[Feature] = ()) -> Iterator[Line]: """Split according to delimiters of the highest priority. - If `py36` is True, the split will add trailing commas also in function - signatures that contain `*` and `**`. + If the appropriate Features are given, the split will add trailing commas + also in function signatures and calls that contain `*` and `**`. """ try: last_leaf = line.leaves[-1] @@ -2418,23 +2495,29 @@ def delimiter_split(line: Line, py36: bool = False) -> Iterator[Line]: nonlocal current_line try: current_line.append_safe(leaf, preformatted=True) - except ValueError as ve: + except ValueError: yield current_line current_line = Line(depth=line.depth, inside_brackets=line.inside_brackets) current_line.append(leaf) - for index, leaf in enumerate(line.leaves): + for leaf in line.leaves: yield from append_to_line(leaf) - for comment_after in line.comments_after(leaf, index): + for comment_after in line.comments_after(leaf): yield from append_to_line(comment_after) lowest_depth = min(lowest_depth, leaf.bracket_depth) - if leaf.bracket_depth == lowest_depth and is_vararg( - leaf, within=VARARGS_PARENTS - ): - trailing_comma_safe = trailing_comma_safe and py36 + if leaf.bracket_depth == lowest_depth: + if is_vararg(leaf, within={syms.typedargslist}): + trailing_comma_safe = ( + trailing_comma_safe and Feature.TRAILING_COMMA_IN_DEF in features + ) + elif is_vararg(leaf, within={syms.arglist, syms.argument}): + trailing_comma_safe = ( + trailing_comma_safe and Feature.TRAILING_COMMA_IN_CALL in features + ) + leaf_priority = bt.delimiters.get(id(leaf)) if leaf_priority == delimiter_priority: yield current_line @@ -2452,7 +2535,9 @@ def delimiter_split(line: Line, py36: bool = False) -> Iterator[Line]: @dont_increase_indentation -def standalone_comment_split(line: Line, py36: bool = False) -> Iterator[Line]: +def standalone_comment_split( + line: Line, features: Collection[Feature] = () +) -> Iterator[Line]: """Split standalone comments from the rest of the line.""" if not line.contains_standalone_comments(0): raise CannotSplit("Line does not have any standalone comments") @@ -2464,16 +2549,16 @@ def standalone_comment_split(line: Line, py36: bool = False) -> Iterator[Line]: nonlocal current_line try: current_line.append_safe(leaf, preformatted=True) - except ValueError as ve: + except ValueError: yield current_line current_line = Line(depth=line.depth, inside_brackets=line.inside_brackets) current_line.append(leaf) - for index, leaf in enumerate(line.leaves): + for leaf in line.leaves: yield from append_to_line(leaf) - for comment_after in line.comments_after(leaf, index): + for comment_after in line.comments_after(leaf): yield from append_to_line(comment_after) if current_line: @@ -2494,6 +2579,14 @@ def is_import(leaf: Leaf) -> bool: ) +def is_type_comment(leaf: Leaf) -> bool: + """Return True if the given leaf is a special comment. + Only returns true for type comments for now.""" + t = leaf.type + v = leaf.value + return t in {token.COMMENT, t == STANDALONE_COMMENT} and v.startswith("# type:") + + def normalize_prefix(leaf: Leaf, *, inside_brackets: bool) -> None: """Leave existing extra newlines if not `inside_brackets`. Remove everything else. @@ -2595,6 +2688,51 @@ def normalize_string_quotes(leaf: Leaf) -> None: leaf.value = f"{prefix}{new_quote}{new_body}{new_quote}" +def normalize_numeric_literal(leaf: Leaf) -> None: + """Normalizes numeric (float, int, and complex) literals. + + All letters used in the representation are normalized to lowercase (except + in Python 2 long literals). + """ + text = leaf.value.lower() + if text.startswith(("0o", "0b")): + # Leave octal and binary literals alone. + pass + elif text.startswith("0x"): + # Change hex literals to upper case. + before, after = text[:2], text[2:] + text = f"{before}{after.upper()}" + elif "e" in text: + before, after = text.split("e") + sign = "" + if after.startswith("-"): + after = after[1:] + sign = "-" + elif after.startswith("+"): + after = after[1:] + before = format_float_or_int_string(before) + text = f"{before}e{sign}{after}" + elif text.endswith(("j", "l")): + number = text[:-1] + suffix = text[-1] + # Capitalize in "2L" because "l" looks too similar to "1". + if suffix == "l": + suffix = "L" + text = f"{format_float_or_int_string(number)}{suffix}" + else: + text = format_float_or_int_string(text) + leaf.value = text + + +def format_float_or_int_string(text: str) -> str: + """Formats a float string like "1.0".""" + if "." not in text: + return text + + before, after = text.split(".") + return f"{before or 0}.{after or 0}" + + def normalize_invisible_parens(node: Node, parens_after: Set[str]) -> None: """Make existing optional parentheses invisible or create new ones. @@ -2611,9 +2749,21 @@ def normalize_invisible_parens(node: Node, parens_after: Set[str]) -> None: check_lpar = False for index, child in enumerate(list(node.children)): + # Add parentheses around long tuple unpacking in assignments. + if ( + index == 0 + and isinstance(child, Node) + and child.type == syms.testlist_star_expr + ): + check_lpar = True + if check_lpar: if child.type == syms.atom: - maybe_make_parens_invisible_in_atom(child) + if maybe_make_parens_invisible_in_atom(child, parent=node): + lpar = Leaf(token.LPAR, "") + rpar = Leaf(token.RPAR, "") + index = child.remove() or 0 + node.insert_child(index, Node(syms.atom, [lpar, child, rpar])) elif is_one_tuple(child): # wrap child in visible parentheses lpar = Leaf(token.LPAR, "(") @@ -2638,18 +2788,103 @@ def normalize_invisible_parens(node: Node, parens_after: Set[str]) -> None: lpar = Leaf(token.LPAR, "") rpar = Leaf(token.RPAR, "") index = child.remove() or 0 - node.insert_child(index, Node(syms.atom, [lpar, child, rpar])) + prefix = child.prefix + child.prefix = "" + new_child = Node(syms.atom, [lpar, child, rpar]) + new_child.prefix = prefix + node.insert_child(index, new_child) check_lpar = isinstance(child, Leaf) and child.value in parens_after -def maybe_make_parens_invisible_in_atom(node: LN) -> bool: - """If it's safe, make the parens in the atom `node` invisible, recursively.""" +def normalize_fmt_off(node: Node) -> None: + """Convert content between `# fmt: off`/`# fmt: on` into standalone comments.""" + try_again = True + while try_again: + try_again = convert_one_fmt_off_pair(node) + + +def convert_one_fmt_off_pair(node: Node) -> bool: + """Convert content of a single `# fmt: off`/`# fmt: on` into a standalone comment. + + Returns True if a pair was converted. + """ + for leaf in node.leaves(): + previous_consumed = 0 + for comment in list_comments(leaf.prefix, is_endmarker=False): + if comment.value in FMT_OFF: + # We only want standalone comments. If there's no previous leaf or + # the previous leaf is indentation, it's a standalone comment in + # disguise. + if comment.type != STANDALONE_COMMENT: + prev = preceding_leaf(leaf) + if prev and prev.type not in WHITESPACE: + continue + + ignored_nodes = list(generate_ignored_nodes(leaf)) + if not ignored_nodes: + continue + + first = ignored_nodes[0] # Can be a container node with the `leaf`. + parent = first.parent + prefix = first.prefix + first.prefix = prefix[comment.consumed :] + hidden_value = ( + comment.value + "\n" + "".join(str(n) for n in ignored_nodes) + ) + if hidden_value.endswith("\n"): + # That happens when one of the `ignored_nodes` ended with a NEWLINE + # leaf (possibly followed by a DEDENT). + hidden_value = hidden_value[:-1] + first_idx = None + for ignored in ignored_nodes: + index = ignored.remove() + if first_idx is None: + first_idx = index + assert parent is not None, "INTERNAL ERROR: fmt: on/off handling (1)" + assert first_idx is not None, "INTERNAL ERROR: fmt: on/off handling (2)" + parent.insert_child( + first_idx, + Leaf( + STANDALONE_COMMENT, + hidden_value, + prefix=prefix[:previous_consumed] + "\n" * comment.newlines, + ), + ) + return True + + previous_consumed = comment.consumed + + return False + + +def generate_ignored_nodes(leaf: Leaf) -> Iterator[LN]: + """Starting from the container of `leaf`, generate all leaves until `# fmt: on`. + + Stops at the end of the block. + """ + container: Optional[LN] = container_of(leaf) + while container is not None and container.type != token.ENDMARKER: + for comment in list_comments(container.prefix, is_endmarker=False): + if comment.value in FMT_ON: + return + + yield container + + container = container.next_sibling + + +def maybe_make_parens_invisible_in_atom(node: LN, parent: LN) -> bool: + """If it's safe, make the parens in the atom `node` invisible, recursively. + + Returns whether the node should itself be wrapped in invisible parentheses. + + """ if ( node.type != syms.atom or is_empty_tuple(node) or is_one_tuple(node) - or is_yield(node) + or (is_yield(node) and parent.type != syms.expr_stmt) or max_delimiter_priority_in_atom(node) >= COMMA_PRIORITY ): return False @@ -2661,10 +2896,10 @@ def maybe_make_parens_invisible_in_atom(node: LN) -> bool: first.value = "" # type: ignore last.value = "" # type: ignore if len(node.children) > 1: - maybe_make_parens_invisible_in_atom(node.children[1]) - return True + maybe_make_parens_invisible_in_atom(node.children[1], parent=parent) + return False - return False + return True def is_empty_tuple(node: LN) -> bool: @@ -2821,6 +3056,7 @@ def ensure_visible(leaf: Leaf) -> None: def should_explode(line: Line, opening_bracket: Leaf) -> bool: """Should `line` immediately be split with `delimiter_split()` after RHS?""" + if not ( opening_bracket.parent and opening_bracket.parent.type in {syms.atom, syms.import_from} @@ -2838,34 +3074,53 @@ def should_explode(line: Line, opening_bracket: Leaf) -> bool: return max_priority == COMMA_PRIORITY -def is_python36(node: Node) -> bool: - """Return True if the current file is using Python 3.6+ features. +def get_features_used(node: Node) -> Set[Feature]: + """Return a set of (relatively) new Python features used in this file. Currently looking for: - - f-strings; and + - f-strings; + - underscores in numeric literals; and - trailing commas after * or ** in function signatures and calls. """ + features: Set[Feature] = set() for n in node.pre_order(): if n.type == token.STRING: value_head = n.value[:2] # type: ignore if value_head in {'f"', 'F"', "f'", "F'", "rf", "fr", "RF", "FR"}: - return True + features.add(Feature.F_STRINGS) + + elif n.type == token.NUMBER: + if "_" in n.value: # type: ignore + features.add(Feature.NUMERIC_UNDERSCORES) elif ( n.type in {syms.typedargslist, syms.arglist} and n.children and n.children[-1].type == token.COMMA ): + if n.type == syms.typedargslist: + feature = Feature.TRAILING_COMMA_IN_DEF + else: + feature = Feature.TRAILING_COMMA_IN_CALL + for ch in n.children: if ch.type in STARS: - return True + features.add(feature) if ch.type == syms.argument: for argch in ch.children: if argch.type in STARS: - return True + features.add(feature) - return False + return features + + +def detect_target_versions(node: Node) -> Set[TargetVersion]: + """Detect the version to target based on the nodes used.""" + features = get_features_used(node) + return { + version for version in TargetVersion if features <= VERSION_TO_FEATURES[version] + } def generate_trailers_to_omit(line: Line, line_length: int) -> Iterator[Set[LeafID]]: @@ -2884,7 +3139,6 @@ def generate_trailers_to_omit(line: Line, line_length: int) -> Iterator[Set[Leaf length = 4 * line.depth opening_bracket = None closing_bracket = None - optional_brackets: Set[LeafID] = set() inner_brackets: Set[LeafID] = set() for index, leaf, leaf_length in enumerate_with_length(line, reversed=True): length += leaf_length @@ -2895,17 +3149,12 @@ def generate_trailers_to_omit(line: Line, line_length: int) -> Iterator[Set[Leaf if leaf.type == STANDALONE_COMMENT or has_inline_comment: break - optional_brackets.discard(id(leaf)) if opening_bracket: if leaf is opening_bracket: opening_bracket = None elif leaf.type in CLOSING_BRACKETS: inner_brackets.add(id(leaf)) elif leaf.type in CLOSING_BRACKETS: - if not leaf.value: - optional_brackets.add(id(opening_bracket)) - continue - if index > 0 and line.leaves[index - 1].type in OPENING_BRACKETS: # Empty brackets would fail a split so treat them as "inner" # brackets (e.g. only add them to the `omit` set if another @@ -2913,18 +3162,36 @@ def generate_trailers_to_omit(line: Line, line_length: int) -> Iterator[Set[Leaf inner_brackets.add(id(leaf)) continue - opening_bracket = leaf.opening_bracket if closing_bracket: omit.add(id(closing_bracket)) omit.update(inner_brackets) inner_brackets.clear() yield omit - closing_bracket = leaf + + if leaf.value: + opening_bracket = leaf.opening_bracket + closing_bracket = leaf def get_future_imports(node: Node) -> Set[str]: """Return a set of __future__ imports in the file.""" - imports = set() + imports: Set[str] = set() + + def get_imports_from_children(children: List[LN]) -> Generator[str, None, None]: + for child in children: + if isinstance(child, Leaf): + if child.type == token.NAME: + yield child.value + elif child.type == syms.import_as_name: + orig_name = child.children[0] + assert isinstance(orig_name, Leaf), "Invalid syntax parsing imports" + assert orig_name.type == token.NAME, "Invalid syntax parsing imports" + yield orig_name.value + elif child.type == syms.import_as_names: + yield from get_imports_from_children(child.children) + else: + raise AssertionError("Invalid syntax parsing imports") + for child in node.children: if child.type != syms.simple_stmt: break @@ -2943,15 +3210,7 @@ def get_future_imports(node: Node) -> Set[str]: module_name = first_child.children[1] if not isinstance(module_name, Leaf) or module_name.value != "__future__": break - for import_from_child in first_child.children[3:]: - if isinstance(import_from_child, Leaf): - if import_from_child.type == token.NAME: - imports.add(import_from_child.value) - else: - assert import_from_child.type == syms.import_as_names - for leaf in import_from_child.children: - if isinstance(leaf, Leaf) and leaf.type == token.NAME: - imports.add(leaf.value) + imports |= set(get_imports_from_children(first_child.children[3:])) else: break return imports @@ -2967,7 +3226,7 @@ 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. - Symbolic links pointing outside of the root directory are ignored. + Symbolic links pointing outside of the `root` directory are ignored. `report` is where output about exclusions goes. """ @@ -2978,8 +3237,7 @@ def gen_python_files_in_dir( except ValueError: if child.is_symlink(): report.path_ignored( - child, - "is a symbolic link that points outside of the root directory", + child, f"is a symbolic link that points outside {root}" ) continue @@ -3077,7 +3335,7 @@ class Report: - otherwise return 0. """ # According to http://tldp.org/LDP/abs/html/exitcodes.html starting with - # 126 we have special returncodes reserved by the shell. + # 126 we have special return codes reserved by the shell. if self.failure_count: return 123 @@ -3136,7 +3394,16 @@ def assert_equivalent(src: str, dst: str) -> None: if isinstance(value, list): for item in value: - if isinstance(item, ast.AST): + # Ignore nested tuples within del statements, because we may insert + # parentheses and they change the AST. + if ( + field == "targets" + and isinstance(node, ast.Delete) + and isinstance(item, ast.Tuple) + ): + for item in item.elts: + yield from _v(item, depth + 2) + elif isinstance(item, ast.AST): yield from _v(item, depth + 2) elif isinstance(value, ast.AST): @@ -3163,7 +3430,7 @@ def assert_equivalent(src: str, dst: str) -> None: log = dump_to_file("".join(traceback.format_tb(exc.__traceback__)), dst) raise AssertionError( f"INTERNAL ERROR: Black produced invalid code: {exc}. " - f"Please report a bug on https://github.com/ambv/black/issues. " + f"Please report a bug on https://github.com/python/black/issues. " f"This invalid output might be helpful: {log}" ) from None @@ -3174,16 +3441,14 @@ def assert_equivalent(src: str, dst: str) -> None: raise AssertionError( f"INTERNAL ERROR: Black produced code that is not equivalent to " f"the source. " - f"Please report a bug on https://github.com/ambv/black/issues. " + f"Please report a bug on https://github.com/python/black/issues. " f"This diff might be helpful: {log}" ) from None -def assert_stable( - src: str, dst: str, line_length: int, mode: FileMode = FileMode.AUTO_DETECT -) -> None: +def assert_stable(src: str, dst: str, mode: FileMode) -> None: """Raise AssertionError if `dst` reformats differently the second time.""" - newdst = format_str(dst, line_length=line_length, mode=mode) + newdst = format_str(dst, mode=mode) if dst != newdst: log = dump_to_file( diff(src, dst, "source", "first pass"), @@ -3192,7 +3457,7 @@ def assert_stable( raise AssertionError( f"INTERNAL ERROR: Black produced different code on the second pass " f"of the formatter. " - f"Please report a bug on https://github.com/ambv/black/issues. " + f"Please report a bug on https://github.com/python/black/issues. " f"This diff might be helpful: {log}" ) from None @@ -3232,8 +3497,12 @@ def cancel(tasks: Iterable[asyncio.Task]) -> None: def shutdown(loop: BaseEventLoop) -> None: """Cancel all pending tasks on `loop`, wait for them, and close the loop.""" try: + if sys.version_info[:2] >= (3, 7): + all_tasks = asyncio.all_tasks + else: + all_tasks = asyncio.Task.all_tasks # This part is borrowed from asyncio/runners.py in Python 3.7b2. - to_cancel = [task for task in asyncio.Task.all_tasks(loop) if not task.done()] + to_cancel = [task for task in all_tasks(loop) if not task.done()] if not to_cancel: return @@ -3295,7 +3564,7 @@ def enumerate_with_length( return # Multiline strings, we can't continue. comment: Optional[Leaf] - for comment in line.comments_after(leaf, index): + for comment in line.comments_after(leaf): length += len(comment.value) yield index, leaf, length @@ -3440,16 +3709,16 @@ def can_omit_invisible_parens(line: Line, line_length: int) -> bool: return False -def get_cache_file(line_length: int, mode: FileMode) -> Path: - return CACHE_DIR / f"cache.{line_length}.{mode.value}.pickle" +def get_cache_file(mode: FileMode) -> Path: + return CACHE_DIR / f"cache.{mode.get_cache_key()}.pickle" -def read_cache(line_length: int, mode: FileMode) -> Cache: +def read_cache(mode: FileMode) -> Cache: """Read the cache if it exists and is well formed. If it is not well formed, the call to write_cache later should resolve the issue. """ - cache_file = get_cache_file(line_length, mode) + cache_file = get_cache_file(mode) if not cache_file.exists(): return {} @@ -3484,20 +3753,46 @@ def filter_cached(cache: Cache, sources: Iterable[Path]) -> Tuple[Set[Path], Set return todo, done -def write_cache( - cache: Cache, sources: Iterable[Path], line_length: int, mode: FileMode -) -> None: +def write_cache(cache: Cache, sources: Iterable[Path], mode: FileMode) -> None: """Update the cache file.""" - cache_file = get_cache_file(line_length, mode) + cache_file = get_cache_file(mode) try: - if not CACHE_DIR.exists(): - CACHE_DIR.mkdir(parents=True) + CACHE_DIR.mkdir(parents=True, exist_ok=True) new_cache = {**cache, **{src.resolve(): get_cache_info(src) for src in sources}} - with cache_file.open("wb") as fobj: - pickle.dump(new_cache, fobj, protocol=pickle.HIGHEST_PROTOCOL) + with tempfile.NamedTemporaryFile(dir=str(cache_file.parent), delete=False) as f: + pickle.dump(new_cache, f, protocol=pickle.HIGHEST_PROTOCOL) + os.replace(f.name, cache_file) except OSError: pass -if __name__ == "__main__": +def patch_click() -> None: + """Make Click not crash. + + 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 + application. Click refuses to work in this scenario by raising a RuntimeError. + + In case of Black the likelihood that non-ASCII characters are going to be used in + file paths is minimal since it's Python source code. Moreover, this crash was + spurious on Python 3.7 thanks to PEP 538 and PEP 540. + """ + try: + from click import core + from click import _unicodefun # type: ignore + except ModuleNotFoundError: + return + + for module in (core, _unicodefun): + if hasattr(module, "_verify_python3_env"): + module._verify_python3_env = lambda: None + + +def patched_main() -> None: + freeze_support() + patch_click() main() + + +if __name__ == "__main__": + patched_main()