X-Git-Url: https://git.madduck.net/etc/vim.git/blobdiff_plain/250ba7f04b300df284ba80cd4bb4122b45b41efb..3bfb66971f03da39ae1f4c98c30d55e60f63d33b:/black.py diff --git a/black.py b/black.py index 34bd59e..0776983 100644 --- a/black.py +++ b/black.py @@ -1,6 +1,7 @@ +import ast import asyncio -from asyncio.base_events import BaseEventLoop from concurrent.futures import Executor, ProcessPoolExecutor +from contextlib import contextmanager from datetime import datetime from enum import Enum from functools import lru_cache, partial, wraps @@ -11,11 +12,12 @@ from multiprocessing import Manager, freeze_support import os from pathlib import Path import pickle -import re +import regex as re import signal import sys import tempfile import tokenize +import traceback from typing import ( Any, Callable, @@ -40,6 +42,7 @@ from appdirs import user_cache_dir from attr import dataclass, evolve, Factory import click import toml +from typed_ast import ast3, ast27 # lib2to3 fork from blib2to3.pytree import Node, Leaf, type_repr @@ -48,8 +51,8 @@ from blib2to3.pgen2 import driver, token from blib2to3.pgen2.grammar import Grammar from blib2to3.pgen2.parse import ParseError +from _version import version as __version__ -__version__ = "18.9b0" DEFAULT_LINE_LENGTH = 88 DEFAULT_EXCLUDES = ( r"/(\.eggs|\.git|\.hg|\.mypy_cache|\.nox|\.tox|\.venv|_build|buck-out|build|dist)/" @@ -68,7 +71,7 @@ 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] @@ -113,20 +116,19 @@ class Changed(Enum): class TargetVersion(Enum): - PYPY35 = 1 - CPY27 = 2 - CPY33 = 3 - CPY34 = 4 - CPY35 = 5 - CPY36 = 6 - CPY37 = 7 - CPY38 = 8 + PY27 = 2 + PY33 = 3 + PY34 = 4 + PY35 = 5 + PY36 = 6 + PY37 = 7 + PY38 = 8 def is_python2(self) -> bool: - return self is TargetVersion.CPY27 + return self is TargetVersion.PY27 -PY36_VERSIONS = {TargetVersion.CPY36, TargetVersion.CPY37, TargetVersion.CPY38} +PY36_VERSIONS = {TargetVersion.PY36, TargetVersion.PY37, TargetVersion.PY38} class Feature(Enum): @@ -134,32 +136,50 @@ class Feature(Enum): UNICODE_LITERALS = 1 F_STRINGS = 2 NUMERIC_UNDERSCORES = 3 - TRAILING_COMMA = 4 + TRAILING_COMMA_IN_CALL = 4 + TRAILING_COMMA_IN_DEF = 5 + # The following two feature-flags are mutually exclusive, and exactly one should be + # set for every version of python. + ASYNC_IDENTIFIERS = 6 + ASYNC_KEYWORDS = 7 + ASSIGNMENT_EXPRESSIONS = 8 + POS_ONLY_ARGUMENTS = 9 VERSION_TO_FEATURES: Dict[TargetVersion, Set[Feature]] = { - TargetVersion.CPY27: set(), - TargetVersion.PYPY35: {Feature.UNICODE_LITERALS, Feature.F_STRINGS}, - TargetVersion.CPY33: {Feature.UNICODE_LITERALS}, - TargetVersion.CPY34: {Feature.UNICODE_LITERALS}, - TargetVersion.CPY35: {Feature.UNICODE_LITERALS, Feature.TRAILING_COMMA}, - TargetVersion.CPY36: { + TargetVersion.PY27: {Feature.ASYNC_IDENTIFIERS}, + TargetVersion.PY33: {Feature.UNICODE_LITERALS, Feature.ASYNC_IDENTIFIERS}, + TargetVersion.PY34: {Feature.UNICODE_LITERALS, Feature.ASYNC_IDENTIFIERS}, + TargetVersion.PY35: { + Feature.UNICODE_LITERALS, + Feature.TRAILING_COMMA_IN_CALL, + Feature.ASYNC_IDENTIFIERS, + }, + TargetVersion.PY36: { Feature.UNICODE_LITERALS, Feature.F_STRINGS, Feature.NUMERIC_UNDERSCORES, - Feature.TRAILING_COMMA, + Feature.TRAILING_COMMA_IN_CALL, + Feature.TRAILING_COMMA_IN_DEF, + Feature.ASYNC_IDENTIFIERS, }, - TargetVersion.CPY37: { + TargetVersion.PY37: { Feature.UNICODE_LITERALS, Feature.F_STRINGS, Feature.NUMERIC_UNDERSCORES, - Feature.TRAILING_COMMA, + Feature.TRAILING_COMMA_IN_CALL, + Feature.TRAILING_COMMA_IN_DEF, + Feature.ASYNC_KEYWORDS, }, - TargetVersion.CPY38: { + TargetVersion.PY38: { Feature.UNICODE_LITERALS, Feature.F_STRINGS, Feature.NUMERIC_UNDERSCORES, - Feature.TRAILING_COMMA, + Feature.TRAILING_COMMA_IN_CALL, + Feature.TRAILING_COMMA_IN_DEF, + Feature.ASYNC_KEYWORDS, + Feature.ASSIGNMENT_EXPRESSIONS, + Feature.POS_ONLY_ARGUMENTS, }, } @@ -229,6 +249,7 @@ 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", @@ -254,7 +275,8 @@ def read_pyproject_toml( 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( @@ -320,7 +342,7 @@ def read_pyproject_toml( "--quiet", is_flag=True, help=( - "Don't emit non-error messages to stderr. Errors are still emitted, " + "Don't emit non-error messages to stderr. Errors are still emitted; " "silence those with 2>/dev/null." ), ) @@ -354,6 +376,7 @@ def read_pyproject_toml( @click.pass_context def main( ctx: click.Context, + code: Optional[str], line_length: int, target_version: List[TargetVersion], check: bool, @@ -378,6 +401,10 @@ def main( 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. @@ -390,6 +417,9 @@ def main( ) 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: @@ -403,6 +433,7 @@ def main( report = Report(check=check, quiet=quiet, verbose=verbose) root = find_project_root(src) sources: Set[Path] = set() + path_empty(src, quiet, verbose, ctx) for s in src: p = Path(s) if p.is_dir(): @@ -416,7 +447,7 @@ def main( err(f"invalid path: {s}") if len(sources) == 0: if verbose or not quiet: - out("No paths given. Nothing to do 😴") + out("No Python files are present to be formatted. Nothing to do 😴") ctx.exit(0) if len(sources) == 1: @@ -428,36 +459,32 @@ def main( report=report, ) else: - loop = asyncio.get_event_loop() - executor = ProcessPoolExecutor(max_workers=os.cpu_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) + 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}") + out("Oh no! 💥 💔 💥" if report.return_code else "All done! ✨ 🍰 ✨") click.secho(str(report), err=True) ctx.exit(report.return_code) +def path_empty(src: Tuple[str], quiet: bool, verbose: bool, ctx: click.Context) -> None: + """ + Exit if there is no `src` provided for formatting + """ + if not src: + if verbose or not quiet: + out("No Path provided. Nothing to do 😴") + ctx.exit(0) + + def reformat_one( src: Path, fast: bool, write_back: WriteBack, mode: FileMode, report: "Report" ) -> None: """Reformat a single file under `src` without spawning child processes. - If `quiet` is True, non-error messages are not output. `line_length`, - `write_back`, `fast` and `pyi` options are passed to + `fast`, `write_back`, and `mode` options are passed to :func:`format_file_in_place` or :func:`format_stdin_to_stdout`. """ try: @@ -485,20 +512,51 @@ def reformat_one( 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) + executor.shutdown() + + async def schedule_formatting( sources: Set[Path], fast: bool, write_back: WriteBack, mode: FileMode, report: "Report", - loop: BaseEventLoop, + loop: asyncio.AbstractEventLoop, executor: Executor, ) -> None: """Run formatting of `sources` in parallel using the provided `executor`. (Use ProcessPoolExecutors for actual parallelism.) - `line_length`, `write_back`, `fast`, and `pyi` options are passed to + `write_back`, `fast`, and `mode` options are passed to :func:`format_file_in_place`. """ cache: Cache = {} @@ -519,12 +577,14 @@ async def schedule_formatting( manager = Manager() lock = manager.Lock() tasks = { - loop.run_in_executor( - executor, format_file_in_place, src, fast, mode, write_back, lock + asyncio.ensure_future( + loop.run_in_executor( + executor, format_file_in_place, src, fast, mode, write_back, lock + ) ): src for src in sorted(sources) } - pending: Iterable[asyncio.Task] = tasks.keys() + pending: Iterable[asyncio.Future] = tasks.keys() try: loop.add_signal_handler(signal.SIGINT, cancel, pending) loop.add_signal_handler(signal.SIGTERM, cancel, pending) @@ -565,7 +625,7 @@ def format_file_in_place( 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`. + `mode` and `fast` options are passed to :func:`format_file_contents`. """ if src.suffix == ".pyi": mode = evolve(mode, is_pyi=True) @@ -586,9 +646,8 @@ def format_file_in_place( 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 lock: - lock.acquire() - try: + + with lock or nullcontext(): f = io.TextIOWrapper( sys.stdout.buffer, encoding=encoding, @@ -597,9 +656,7 @@ def format_file_in_place( ) f.write(diff_contents) f.detach() - finally: - if lock: - lock.release() + return True @@ -643,7 +700,7 @@ def format_file_contents( If `fast` is False, additionally confirm that the reformatted code is valid by calling :func:`assert_equivalent` and :func:`assert_stable` on it. - `line_length` is passed to :func:`format_str`. + `mode` is passed to :func:`format_str`. """ if src_contents.strip() == "": raise NothingChanged @@ -661,10 +718,11 @@ def format_file_contents( 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. + `mode` determines formatting options, such as how many characters per line are + allowed. """ src_node = lib2to3_parse(src_contents.lstrip(), mode.target_versions) - dst_contents = "" + dst_contents = [] future_imports = get_future_imports(src_node) if mode.target_versions: versions = mode.target_versions @@ -680,19 +738,22 @@ def format_str(src_contents: str, *, mode: FileMode) -> FileContent: 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) + dst_contents.append(str(empty_line)) before, after = elt.maybe_empty_lines(current_line) for _ in range(before): - dst_contents += str(empty_line) + dst_contents.append(str(empty_line)) for line in split_line( - current_line, - line_length=mode.line_length, - supports_trailing_commas=supports_feature(versions, Feature.TRAILING_COMMA), + current_line, line_length=mode.line_length, features=split_line_features ): - dst_contents += str(line) - return dst_contents + dst_contents.append(str(line)) + return "".join(dst_contents) def decode_bytes(src: bytes) -> Tuple[FileContent, Encoding, NewLine]: @@ -712,24 +773,42 @@ 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: - return GRAMMARS - elif all(not version.is_python2() for version in target_versions): - # Python 2-compatible code, so don't try Python 3 grammar. + # No target_version specified, so try all grammars. return [ + # Python 3.7+ + pygram.python_grammar_no_print_statement_no_exec_statement_async_keywords, + # Python 3.0-3.6 pygram.python_grammar_no_print_statement_no_exec_statement, + # Python 2.7 with future print_function import + pygram.python_grammar_no_print_statement, + # Python 2.7 + pygram.python_grammar, + ] + elif all(version.is_python2() for version in target_versions): + # Python 2-only code, so try Python 2 grammars. + return [ + # Python 2.7 with future print_function import pygram.python_grammar_no_print_statement, + # Python 2.7 + pygram.python_grammar, ] else: - return [pygram.python_grammar] + # Python 3-compatible code, so only try Python 3 grammar. + grammars = [] + # If we have to parse both, try to parse async as a keyword first + if not supports_feature(target_versions, Feature.ASYNC_IDENTIFIERS): + # Python 3.7+ + grammars.append( + pygram.python_grammar_no_print_statement_no_exec_statement_async_keywords # noqa: B950 + ) + if not supports_feature(target_versions, Feature.ASYNC_KEYWORDS): + # Python 3.0-3.6 + grammars.append(pygram.python_grammar_no_print_statement_no_exec_statement) + # At least one of the above branches must have been taken, because every Python + # version has exactly one of the two 'ASYNC_*' flags + return grammars def lib2to3_parse(src_txt: str, target_versions: Iterable[TargetVersion] = ()) -> Node: @@ -869,6 +948,7 @@ MATH_OPERATORS = { token.DOUBLESTAR, } STARS = {token.STAR, token.DOUBLESTAR} +VARARGS_SPECIALS = STARS | {token.SLASH} VARARGS_PARENTS = { syms.arglist, syms.argument, # double star in arglist @@ -996,7 +1076,7 @@ class BracketTracker: """Return True if there is an yet unmatched open bracket on the line.""" return bool(self.bracket_match) - def max_delimiter_priority(self, exclude: Iterable[LeafID] = ()) -> int: + def max_delimiter_priority(self, exclude: Iterable[LeafID] = ()) -> Priority: """Return the highest priority of a delimiter found on the line. Values are consistent with what `is_split_*_delimiter()` return. @@ -1004,7 +1084,7 @@ class BracketTracker: """ return max(v for k, v in self.delimiters.items() if k not in exclude) - def delimiter_count_with_priority(self, priority: int = 0) -> int: + def delimiter_count_with_priority(self, priority: Priority = 0) -> int: """Return the number of delimiters with the given `priority`. If no `priority` is passed, defaults to max priority on the line. @@ -1079,9 +1159,7 @@ class Line: depth: int = 0 leaves: List[Leaf] = Factory(list) - # The LeafID keys of comments must remain ordered by the corresponding leaf's index - # in leaves - comments: Dict[LeafID, List[Leaf]] = Factory(dict) + comments: Dict[LeafID, List[Leaf]] = Factory(dict) # keys ordered like `leaves` bracket_tracker: BracketTracker = Factory(BracketTracker) inside_brackets: bool = False should_explode: bool = False @@ -1212,6 +1290,69 @@ class Line: if leaf.type == STANDALONE_COMMENT: if leaf.bracket_depth <= depth_limit: return True + return False + + def contains_uncollapsable_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 or ( + last_leaf.type == token.RPAR and not last_leaf.value + ): + # When trailing commas or optional parens 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 and invisible. + last_leaf = self.leaves[-2] + ignored_ids.add(id(last_leaf)) + except IndexError: + return False + + # A type comment is uncollapsable if it is attached to a leaf + # that isn't at the end of the line (since that could cause it + # to get associated to a different argument) or if there are + # comments before it (since that could cause it to get hidden + # behind a comment. + comment_seen = False + for leaf_id, comments in self.comments.items(): + for comment in comments: + if is_type_comment(comment): + if leaf_id not in ignored_ids or comment_seen: + return True + + comment_seen = True + + return False + + def contains_unsplittable_type_ignore(self) -> bool: + if not self.leaves: + return False + + # If a 'type: ignore' is attached to the end of a line, we + # can't split the line, because we can't know which of the + # subexpressions the ignore was meant to apply to. + # + # We only want this to apply to actual physical lines from the + # original source, though: we don't want the presence of a + # 'type: ignore' at the end of a multiline expression to + # justify pushing it all onto one line. Thus we + # (unfortunately) need to check the actual source lines and + # only report an unsplittable 'type: ignore' if this line was + # one line in the original code. + + # Grab the first and last line numbers, skipping generated leaves + first_line = next((l.lineno for l in self.leaves if l.lineno != 0), 0) + last_line = next((l.lineno for l in reversed(self.leaves) if l.lineno != 0), 0) + + if first_line == last_line: + # We look at the last two leaves since a comma or an + # invisible paren could have been added at the end of the + # line. + for node in self.leaves[-2:]: + for comment in self.comments.get(id(node), []): + if is_type_comment(comment, " ignore"): + return True return False @@ -1266,7 +1407,10 @@ class Line: bracket_depth = leaf.bracket_depth if bracket_depth == depth and leaf.type == token.COMMA: commas += 1 - if leaf.parent and leaf.parent.type == syms.arglist: + if leaf.parent and leaf.parent.type in { + syms.arglist, + syms.typedargslist, + }: commas += 1 break @@ -1293,13 +1437,24 @@ class Line: comment.prefix = "" return False - else: - leaf_id = id(self.leaves[-1]) - if leaf_id not in self.comments: - self.comments[leaf_id] = [comment] - else: - self.comments[leaf_id].append(comment) - return True + last_leaf = self.leaves[-1] + if ( + last_leaf.type == token.RPAR + and not last_leaf.value + and last_leaf.parent + and len(list(last_leaf.parent.leaves())) <= 3 + and not is_type_comment(comment) + ): + # Comments on an optional parens wrapping a single leaf should belong to + # the wrapped node except if it's a type comment. Pinning the comment like + # this avoids unstable formatting caused by comment migration. + if len(self.leaves) < 2: + comment.type = STANDALONE_COMMENT + comment.prefix = "" + return False + last_leaf = self.leaves[-2] + self.comments.setdefault(id(last_leaf), []).append(comment) + return True def comments_after(self, leaf: Leaf) -> List[Leaf]: """Generate comments that should appear directly after `leaf`.""" @@ -1307,17 +1462,11 @@ class Line: def remove_trailing_comma(self) -> None: """Remove the trailing comma and moves the comments attached to it.""" - # Remember, the LeafID keys of self.comments are ordered by the - # corresponding leaf's index in self.leaves - # If id(self.leaves[-2]) is in self.comments, the order doesn't change. - # Otherwise, we insert it into self.comments, and it becomes the last entry. - # However, since we delete id(self.leaves[-1]) from self.comments, the invariant - # is maintained - self.comments.setdefault(id(self.leaves[-2]), []).extend( - self.comments.get(id(self.leaves[-1]), []) + 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 ) - self.comments.pop(id(self.leaves[-1]), None) - self.leaves.pop() def is_complex_subscript(self, leaf: Leaf) -> bool: """Return True iff `leaf` is part of a slice with non-trivial exprs.""" @@ -1379,7 +1528,13 @@ class EmptyLineTracker: lines (two on module-level). """ before, after = self._maybe_empty_lines(current_line) - before -= self.previous_after + before = ( + # Black should not insert empty lines at the beginning + # of the file + 0 + if self.previous_line is None + else before - self.previous_after + ) self.previous_after = after self.previous_line = current_line return before, after @@ -1527,6 +1682,39 @@ class LineGenerator(Visitor[Line]): self.current_line.append(node) yield from super().visit_default(node) + def visit_atom(self, node: Node) -> Iterator[Line]: + # Always make parentheses invisible around a single node, because it should + # not be needed (except in the case of yield, where removing the parentheses + # produces a SyntaxError). + if ( + len(node.children) == 3 + and isinstance(node.children[0], Leaf) + and node.children[0].type == token.LPAR + and isinstance(node.children[2], Leaf) + and node.children[2].type == token.RPAR + and isinstance(node.children[1], Leaf) + and not ( + node.children[1].type == token.NAME + and node.children[1].value == "yield" + ) + ): + node.children[0].value = "" + node.children[2].value = "" + yield from super().visit_default(node) + + def visit_factor(self, node: Node) -> Iterator[Line]: + """Force parentheses between a unary op and a binary power: + + -2 ** 8 -> -(2 ** 8) + """ + child = node.children[1] + if child.type == syms.power and len(child.children) == 3: + lpar = Leaf(token.LPAR, "(") + rpar = Leaf(token.RPAR, ")") + index = child.remove() or 0 + node.insert_child(index, Node(syms.atom, [lpar, child, rpar])) + yield from self.visit_default(node) + def visit_INDENT(self, node: Node) -> Iterator[Line]: """Increase indentation level, maybe yield a line.""" # In blib2to3 INDENT never holds comments. @@ -1646,6 +1834,7 @@ 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 @@ -1715,7 +1904,7 @@ def whitespace(leaf: Leaf, *, complex_subscript: bool) -> str: # noqa: C901 # that, too. return prevp.prefix - elif prevp.type in STARS: + elif prevp.type in VARARGS_SPECIALS: if is_vararg(prevp, within=VARARGS_PARENTS | UNPACKING_PARENTS): return NO @@ -1805,7 +1994,7 @@ def whitespace(leaf: Leaf, *, complex_subscript: bool) -> str: # noqa: C901 if not prevp or prevp.type == token.LPAR: return NO - elif prev.type in {token.EQUAL} | STARS: + elif prev.type in {token.EQUAL} | VARARGS_SPECIALS: return NO elif p.type == syms.decorator: @@ -1939,7 +2128,7 @@ def container_of(leaf: Leaf) -> LN: return container -def is_split_after_delimiter(leaf: Leaf, previous: Optional[Leaf] = None) -> int: +def is_split_after_delimiter(leaf: Leaf, previous: Optional[Leaf] = None) -> Priority: """Return the priority of the `leaf` delimiter, given a line break after it. The delimiter priorities returned here are from those delimiters that would @@ -1953,7 +2142,7 @@ def is_split_after_delimiter(leaf: Leaf, previous: Optional[Leaf] = None) -> int return 0 -def is_split_before_delimiter(leaf: Leaf, previous: Optional[Leaf] = None) -> int: +def is_split_before_delimiter(leaf: Leaf, previous: Optional[Leaf] = None) -> Priority: """Return the priority of the `leaf` delimiter, given a line break before it. The delimiter priorities returned here are from those delimiters that would @@ -2103,15 +2292,21 @@ def list_comments(prefix: str, *, is_endmarker: bool) -> List[ProtoComment]: consumed = 0 nlines = 0 + ignored_lines = 0 for index, line in enumerate(prefix.split("\n")): consumed += len(line) + 1 # adding the length of the split '\n' line = line.lstrip() if not line: nlines += 1 if not line.startswith("#"): + # Escaped newlines outside of a comment are not really newlines at + # all. We treat a single-line comment following an escaped newline + # as a simple trailing comment. + if line.endswith("\\"): + ignored_lines += 1 continue - if index == 0 and not is_endmarker: + if index == ignored_lines and not is_endmarker: comment_type = token.COMMENT # simple trailing comment else: comment_type = STANDALONE_COMMENT @@ -2148,7 +2343,7 @@ def split_line( line: Line, line_length: int, inner: bool = False, - supports_trailing_commas: bool = False, + features: Collection[Feature] = (), ) -> Iterator[Line]: """Split a `line` into potentially many lines. @@ -2157,7 +2352,7 @@ 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 `supports_trailing_commas` is True, splitting may use the TRAILING_COMMA feature. + `features` are syntactical features that may be used in the output. """ if line.is_comment: yield line @@ -2165,18 +2360,13 @@ def split_line( line_str = str(line).strip("\n") - # we don't want to split special comments like type annotations - # https://github.com/python/typing/issues/186 - has_special_comment = False - for leaf in line.leaves: - for comment in line.comments_after(leaf): - if leaf.type == token.COMMA and is_special_comment(comment): - has_special_comment = True - if ( - not has_special_comment + not line.contains_uncollapsable_type_comments() and not line.should_explode - and is_line_short_enough(line, line_length=line_length, line_str=line_str) + and ( + is_line_short_enough(line, line_length=line_length, line_str=line_str) + or line.contains_unsplittable_type_ignore() + ) ): yield line return @@ -2186,13 +2376,9 @@ def split_line( split_funcs = [left_hand_split] else: - def rhs(line: Line, supports_trailing_commas: 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, supports_trailing_commas, 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 @@ -2200,7 +2386,7 @@ 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, supports_trailing_commas) + yield from right_hand_split(line, line_length, features=features) if line.inside_brackets: split_funcs = [delimiter_split, standalone_comment_split, rhs] @@ -2212,16 +2398,13 @@ def split_line( # split altogether. result: List[Line] = [] try: - for l in split_func(line, supports_trailing_commas): + 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, - supports_trailing_commas=supports_trailing_commas, + l, line_length=line_length, inner=True, features=features ) ) except CannotSplit: @@ -2235,9 +2418,7 @@ def split_line( yield line -def left_hand_split( - line: Line, supports_trailing_commas: 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. @@ -2276,7 +2457,7 @@ def left_hand_split( def right_hand_split( line: Line, line_length: int, - supports_trailing_commas: bool = False, + features: Collection[Feature] = (), omit: Collection[LeafID] = (), ) -> Iterator[Line]: """Split line into many lines, starting with the last matching bracket pair. @@ -2335,12 +2516,7 @@ def right_hand_split( ): omit = {id(closing_bracket), *omit} try: - yield from right_hand_split( - line, - line_length, - supports_trailing_commas=supports_trailing_commas, - omit=omit, - ) + yield from right_hand_split(line, line_length, features=features, omit=omit) return except CannotSplit: @@ -2408,10 +2584,21 @@ def bracket_split_build_line( if leaves: # Since body is a new indent level, remove spurious leading whitespace. normalize_prefix(leaves[0], inside_brackets=True) - # Ensure a trailing comma when expected. - if original.is_import: - if leaves[-1].type != token.COMMA: - leaves.append(Leaf(token.COMMA, ",")) + # Ensure a trailing comma for imports and standalone function arguments, but + # be careful not to add one after any comments. + no_commas = original.is_def and not any( + l.type == token.COMMA for l in leaves + ) + + if original.is_import or no_commas: + 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) @@ -2429,10 +2616,8 @@ def dont_increase_indentation(split_func: SplitFunc) -> SplitFunc: """ @wraps(split_func) - def split_wrapper( - line: Line, supports_trailing_commas: bool = False - ) -> Iterator[Line]: - for l in split_func(line, supports_trailing_commas): + 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 @@ -2440,13 +2625,11 @@ def dont_increase_indentation(split_func: SplitFunc) -> SplitFunc: @dont_increase_indentation -def delimiter_split( - line: Line, supports_trailing_commas: 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] @@ -2485,10 +2668,16 @@ def delimiter_split( 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 supports_trailing_commas + 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 @@ -2507,7 +2696,7 @@ def delimiter_split( @dont_increase_indentation def standalone_comment_split( - line: Line, supports_trailing_commas: bool = False + line: Line, features: Collection[Feature] = () ) -> Iterator[Line]: """Split standalone comments from the rest of the line.""" if not line.contains_standalone_comments(0): @@ -2550,13 +2739,13 @@ def is_import(leaf: Leaf) -> bool: ) -def is_special_comment(leaf: Leaf) -> bool: +def is_type_comment(leaf: Leaf, suffix: str = "") -> 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 bool( - (t == token.COMMENT or t == STANDALONE_COMMENT) and (v.startswith("# type:")) + return t in {token.COMMENT, t == STANDALONE_COMMENT} and v.startswith( + "# type:" + suffix ) @@ -2642,7 +2831,15 @@ def normalize_string_quotes(leaf: Leaf) -> None: new_body = sub_twice(escaped_orig_quote, rf"\1\2{orig_quote}", new_body) new_body = sub_twice(unescaped_new_quote, rf"\1\\{new_quote}", new_body) if "f" in prefix.casefold(): - matches = re.findall(r"[^{]\{(.*?)\}[^}]", new_body) + matches = re.findall( + r""" + (?:[^{]|^)\{ # start of the string or a non-{ followed by a single { + ([^{].*?) # contents of the brackets except if begins with {{ + \}(?:[^}]|$) # A } followed by end of the string or a non-} + """, + new_body, + re.VERBOSE, + ) for m in matches: if "\\" in str(m): # Do not introduce backslashes in interpolated expressions @@ -2709,7 +2906,7 @@ def format_float_or_int_string(text: str) -> str: def normalize_invisible_parens(node: Node, parens_after: Set[str]) -> None: """Make existing optional parentheses invisible or create new ones. - `parens_after` is a set of string leaf values immeditely after which parens + `parens_after` is a set of string leaf values immediately after which parens should be put. Standardizes on visible parentheses for single-element tuples, and keeps @@ -2722,9 +2919,27 @@ 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 is_walrus_assignment(child): + continue if child.type == syms.atom: - if maybe_make_parens_invisible_in_atom(child): + # Determines if the underlying atom should be surrounded with + # invisible params - also makes parens invisible recursively + # within the atom and removes repeated invisible parens within + # the atom + should_surround_with_parens = maybe_make_parens_invisible_in_atom( + child, parent=node + ) + + if should_surround_with_parens: lpar = Leaf(token.LPAR, "") rpar = Leaf(token.RPAR, "") index = child.remove() or 0 @@ -2753,7 +2968,11 @@ 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 @@ -2835,8 +3054,10 @@ def generate_ignored_nodes(leaf: Leaf) -> Iterator[LN]: container = container.next_sibling -def maybe_make_parens_invisible_in_atom(node: LN) -> bool: +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. + Additionally, remove repeated, adjacent invisible parens from the atom `node` + as they are redundant. Returns whether the node should itself be wrapped in invisible parentheses. @@ -2845,7 +3066,7 @@ def maybe_make_parens_invisible_in_atom(node: LN) -> bool: 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 @@ -2853,16 +3074,40 @@ def maybe_make_parens_invisible_in_atom(node: LN) -> bool: first = node.children[0] last = node.children[-1] if first.type == token.LPAR and last.type == token.RPAR: + middle = node.children[1] # make parentheses invisible first.value = "" # type: ignore last.value = "" # type: ignore - if len(node.children) > 1: - maybe_make_parens_invisible_in_atom(node.children[1]) + maybe_make_parens_invisible_in_atom(middle, parent=parent) + + if is_atom_with_invisible_parens(middle): + # Strip the invisible parens from `middle` by replacing + # it with the child in-between the invisible parens + middle.replace(middle.children[1]) + return False return True +def is_atom_with_invisible_parens(node: LN) -> bool: + """Given a `LN`, determines whether it's an atom `node` with invisible + parens. Useful in dedupe-ing and normalizing parens. + """ + if isinstance(node, Leaf) or node.type != syms.atom: + return False + + first, last = node.children[0], node.children[-1] + return ( + isinstance(first, Leaf) + and first.type == token.LPAR + and first.value == "" + and isinstance(last, Leaf) + and last.type == token.RPAR + and last.value == "" + ) + + def is_empty_tuple(node: LN) -> bool: """Return True if `node` holds an empty tuple.""" return ( @@ -2873,18 +3118,24 @@ def is_empty_tuple(node: LN) -> bool: ) +def unwrap_singleton_parenthesis(node: LN) -> Optional[LN]: + """Returns `wrapped` if `node` is of the shape ( wrapped ). + + Parenthesis can be optional. Returns None otherwise""" + if len(node.children) != 3: + return None + lpar, wrapped, rpar = node.children + if not (lpar.type == token.LPAR and rpar.type == token.RPAR): + return None + + return wrapped + + def is_one_tuple(node: LN) -> bool: """Return True if `node` holds a tuple with one element, with or without parens.""" if node.type == syms.atom: - if len(node.children) != 3: - return False - - lpar, gexp, rpar = node.children - if not ( - lpar.type == token.LPAR - and gexp.type == syms.testlist_gexp - and rpar.type == token.RPAR - ): + gexp = unwrap_singleton_parenthesis(node) + if gexp is None or gexp.type != syms.testlist_gexp: return False return len(gexp.children) == 2 and gexp.children[1].type == token.COMMA @@ -2896,6 +3147,12 @@ def is_one_tuple(node: LN) -> bool: ) +def is_walrus_assignment(node: LN) -> bool: + """Return True iff `node` is of the shape ( test := test )""" + inner = unwrap_singleton_parenthesis(node) + return inner is not None and inner.type == syms.namedexpr_test + + def is_yield(node: LN) -> bool: """Return True if `node` holds a `yield` or `yield from` expression.""" if node.type == syms.yield_expr: @@ -2925,7 +3182,7 @@ def is_vararg(leaf: Leaf, within: Set[NodeType]) -> bool: extended iterable unpacking (PEP 3132) and additional unpacking generalizations (PEP 448). """ - if leaf.type not in STARS or not leaf.parent: + if leaf.type not in VARARGS_SPECIALS or not leaf.parent: return False p = leaf.parent @@ -2975,7 +3232,7 @@ def is_stub_body(node: LN) -> bool: ) -def max_delimiter_priority_in_atom(node: LN) -> int: +def max_delimiter_priority_in_atom(node: LN) -> Priority: """Return maximum delimiter priority inside `node`. This is specific to atoms with contents contained in a pair of parentheses. @@ -3007,7 +3264,7 @@ def ensure_visible(leaf: Leaf) -> None: """Make sure parentheses are visible. They could be invisible as part of some statements (see - :func:`normalize_invible_parens` and :func:`visit_import_from`). + :func:`normalize_invisible_parens` and :func:`visit_import_from`). """ if leaf.type == token.LPAR: leaf.value = "(" @@ -3040,8 +3297,9 @@ def get_features_used(node: Node) -> Set[Feature]: Currently looking for: - f-strings; - - underscores in numeric literals; and - - trailing commas after * or ** in function signatures and calls. + - underscores in numeric literals; + - trailing commas after * or ** in function signatures and calls; + - positional only arguments in function signatures and lambdas; """ features: Set[Feature] = set() for n in node.pre_order(): @@ -3054,19 +3312,31 @@ def get_features_used(node: Node) -> Set[Feature]: if "_" in n.value: # type: ignore features.add(Feature.NUMERIC_UNDERSCORES) + elif n.type == token.SLASH: + if n.parent and n.parent.type in {syms.typedargslist, syms.arglist}: + features.add(Feature.POS_ONLY_ARGUMENTS) + + elif n.type == token.COLONEQUAL: + features.add(Feature.ASSIGNMENT_EXPRESSIONS) + 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: - features.add(Feature.TRAILING_COMMA) + features.add(feature) if ch.type == syms.argument: for argch in ch.children: if argch.type in STARS: - features.add(Feature.TRAILING_COMMA) + features.add(feature) return features @@ -3146,7 +3416,7 @@ def get_future_imports(node: Node) -> Set[str]: elif child.type == syms.import_as_names: yield from get_imports_from_children(child.children) else: - assert False, "Invalid syntax parsing imports" + raise AssertionError("Invalid syntax parsing imports") for child in node.children: if child.type != syms.simple_stmt: @@ -3330,17 +3600,58 @@ class Report: return ", ".join(report) + "." +def parse_ast(src: str) -> Union[ast.AST, ast3.AST, ast27.AST]: + filename = "" + if sys.version_info >= (3, 8): + # TODO: support Python 4+ ;) + for minor_version in range(sys.version_info[1], 4, -1): + try: + return ast.parse(src, filename, feature_version=(3, minor_version)) + except SyntaxError: + continue + else: + for feature_version in (7, 6): + try: + return ast3.parse(src, filename, feature_version=feature_version) + except SyntaxError: + continue + + return ast27.parse(src) + + +def _fixup_ast_constants( + node: Union[ast.AST, ast3.AST, ast27.AST] +) -> Union[ast.AST, ast3.AST, ast27.AST]: + """Map ast nodes deprecated in 3.8 to Constant.""" + # casts are required until this is released: + # https://github.com/python/typeshed/pull/3142 + if isinstance(node, (ast.Str, ast3.Str, ast27.Str, ast.Bytes, ast3.Bytes)): + return cast(ast.AST, ast.Constant(value=node.s)) + elif isinstance(node, (ast.Num, ast3.Num, ast27.Num)): + return cast(ast.AST, ast.Constant(value=node.n)) + elif isinstance(node, (ast.NameConstant, ast3.NameConstant)): + return cast(ast.AST, ast.Constant(value=node.value)) + return node + + def assert_equivalent(src: str, dst: str) -> None: """Raise AssertionError if `src` and `dst` aren't equivalent.""" - import ast - import traceback - - def _v(node: ast.AST, depth: int = 0) -> Iterator[str]: + def _v(node: Union[ast.AST, ast3.AST, ast27.AST], depth: int = 0) -> Iterator[str]: """Simple visitor generating strings to compare ASTs by content.""" + + node = _fixup_ast_constants(node) + yield f"{' ' * depth}{node.__class__.__name__}(" for field in sorted(node._fields): + # TypeIgnore has only one field 'lineno' which breaks this comparison + type_ignore_classes = (ast3.TypeIgnore, ast27.TypeIgnore) + if sys.version_info >= (3, 8): + type_ignore_classes += (ast.TypeIgnore,) + if isinstance(node, type_ignore_classes): + break + try: value = getattr(node, field) except AttributeError: @@ -3350,10 +3661,19 @@ 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, ast3.Delete, ast27.Delete)) + and isinstance(item, (ast.Tuple, ast3.Tuple, ast27.Tuple)) + ): + for item in item.elts: + yield from _v(item, depth + 2) + elif isinstance(item, (ast.AST, ast3.AST, ast27.AST)): yield from _v(item, depth + 2) - elif isinstance(value, ast.AST): + elif isinstance(value, (ast.AST, ast3.AST, ast27.AST)): yield from _v(value, depth + 2) else: @@ -3362,22 +3682,20 @@ def assert_equivalent(src: str, dst: str) -> None: yield f"{' ' * depth}) # /{node.__class__.__name__}" try: - src_ast = ast.parse(src) + src_ast = parse_ast(src) except Exception as exc: - major, minor = sys.version_info[:2] raise AssertionError( - f"cannot use --safe with this file; failed to parse source file " - f"with Python {major}.{minor}'s builtin AST. Re-run with --fast " - f"or stop using deprecated Python 2 syntax. AST error message: {exc}" + f"cannot use --safe with this file; failed to parse source file. " + f"AST error message: {exc}" ) try: - dst_ast = ast.parse(dst) + dst_ast = parse_ast(dst) except Exception as exc: 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/psf/black/issues. " f"This invalid output might be helpful: {log}" ) from None @@ -3388,7 +3706,7 @@ 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/psf/black/issues. " f"This diff might be helpful: {log}" ) from None @@ -3404,15 +3722,13 @@ def assert_stable(src: str, dst: str, mode: FileMode) -> None: 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/psf/black/issues. " f"This diff might be helpful: {log}" ) from None def dump_to_file(*output: str) -> str: """Dump `output` to a temporary file. Return path to the file.""" - import tempfile - with tempfile.NamedTemporaryFile( mode="w", prefix="blk_", suffix=".log", delete=False, encoding="utf8" ) as f: @@ -3423,6 +3739,13 @@ def dump_to_file(*output: str) -> str: return f.name +@contextmanager +def nullcontext() -> Iterator[None]: + """Return context manager that does nothing. + Similar to `nullcontext` from python 3.7""" + yield + + def diff(a: str, b: str, a_name: str, b_name: str) -> str: """Return a unified diff string between strings `a` and `b`.""" import difflib @@ -3441,11 +3764,15 @@ def cancel(tasks: Iterable[asyncio.Task]) -> None: task.cancel() -def shutdown(loop: BaseEventLoop) -> None: +def shutdown(loop: asyncio.AbstractEventLoop) -> 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 @@ -3479,7 +3806,8 @@ def re_compile_maybe_verbose(regex: str) -> Pattern[str]: """ if "\n" in regex: regex = "(?x)" + regex - return re.compile(regex) + compiled: Pattern[str] = re.compile(regex) + return compiled def enumerate_reversed(sequence: Sequence[T]) -> Iterator[Tuple[Index, T]]: @@ -3506,7 +3834,6 @@ def enumerate_with_length( if "\n" in leaf.value: return # Multiline strings, we can't continue. - comment: Optional[Leaf] for comment in line.comments_after(leaf): length += len(comment.value)