X-Git-Url: https://git.madduck.net/etc/vim.git/blobdiff_plain/52fda8b0e9e52e94aae6cb3170c9b1b492a2d8b4..ef362b4ea84669ed38ea108aee4117e8fadf1cf0:/black.py diff --git a/black.py b/black.py index 11386d2..dd7fe39 100644 --- a/black.py +++ b/black.py @@ -1,20 +1,20 @@ -#!/usr/bin/env python3 - import asyncio -import pickle from asyncio.base_events import BaseEventLoop from concurrent.futures import Executor, ProcessPoolExecutor -from enum import Enum -from functools import partial, wraps +from datetime import datetime +from enum import Enum, Flag +from functools import lru_cache, partial, wraps +import io import keyword import logging from multiprocessing import Manager import os from pathlib import Path +import pickle import re -import tokenize import signal import sys +import tokenize from typing import ( Any, Callable, @@ -26,16 +26,19 @@ from typing import ( List, Optional, Pattern, + Sequence, Set, Tuple, Type, TypeVar, Union, + cast, ) from appdirs import user_cache_dir from attr import dataclass, Factory import click +import toml # lib2to3 fork from blib2to3.pytree import Node, Leaf, type_repr @@ -43,12 +46,20 @@ from blib2to3 import pygram, pytree from blib2to3.pgen2 import driver, token from blib2to3.pgen2.parse import ParseError -__version__ = "18.4a2" + +__version__ = "18.6b1" DEFAULT_LINE_LENGTH = 88 +DEFAULT_EXCLUDES = ( + r"/(\.git|\.hg|\.mypy_cache|\.tox|\.venv|_build|buck-out|build|dist)/" +) +DEFAULT_INCLUDES = r"\.pyi?$" +CACHE_DIR = Path(user_cache_dir("black", version=__version__)) + + # types -syms = pygram.python_symbols FileContent = str Encoding = str +NewLine = str Depth = int NodeType = int LeafID = int @@ -63,6 +74,9 @@ Cache = Dict[Path, CacheInfo] out = partial(click.secho, bold=True, err=True) err = partial(click.secho, fg="red", err=True) +pygram.initialize(CACHE_DIR) +syms = pygram.python_symbols + class NothingChanged(UserWarning): """Raised by :func:`format_file` when reformatted code is the same as source.""" @@ -88,11 +102,11 @@ class FormatError(Exception): self.consumed = consumed def trim_prefix(self, leaf: Leaf) -> None: - leaf.prefix = leaf.prefix[self.consumed:] + 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] + unformatted_prefix = leaf.prefix[: self.consumed] return Leaf(token.NEWLINE, unformatted_prefix) @@ -109,6 +123,13 @@ class WriteBack(Enum): YES = 1 DIFF = 2 + @classmethod + def from_configuration(cls, *, check: bool, diff: bool) -> "WriteBack": + if check and not diff: + return cls.NO + + return cls.DIFF if diff else cls.YES + class Changed(Enum): NO = 0 @@ -116,6 +137,60 @@ class Changed(Enum): YES = 2 +class FileMode(Flag): + AUTO_DETECT = 0 + PYTHON36 = 1 + PYI = 2 + NO_STRING_NORMALIZATION = 4 + + @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 read_pyproject_toml( + ctx: click.Context, param: click.Parameter, value: Union[str, int, bool, None] +) -> Optional[str]: + """Inject Black configuration from "pyproject.toml" into defaults in `ctx`. + + Returns the path to a successfully found and read configuration file, None + otherwise. + """ + assert not isinstance(value, (int, bool)), "Invalid parameter type passed" + if not value: + root = find_project_root(ctx.params.get("src", ())) + path = root / "pyproject.toml" + if path.is_file(): + value = str(path) + else: + return None + + try: + 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) + + if not config: + return None + + if ctx.default_map is None: + ctx.default_map = {} + ctx.default_map.update( # type: ignore # bad types in .pyi + {k.replace("--", "").replace("-", "_"): v for k, v in config.items()} + ) + return value + + @click.command() @click.option( "-l", @@ -125,6 +200,29 @@ class Changed(Enum): help="How many character per line to allow.", show_default=True, ) +@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]" + ), +) +@click.option( + "--pyi", + is_flag=True, + help=( + "Format all input files like typing stubs regardless of file extension " + "(useful when piping source on standard input)." + ), +) +@click.option( + "-S", + "--skip-string-normalization", + is_flag=True, + help="Don't normalize string quotes or prefixes.", +) @click.option( "--check", is_flag=True, @@ -144,6 +242,31 @@ class Changed(Enum): is_flag=True, help="If --fast given, skip temporary sanity checks. [default: --safe]", ) +@click.option( + "--include", + type=str, + default=DEFAULT_INCLUDES, + help=( + "A regular expression that matches files and directories that should be " + "included on recursive searches. An empty value means all files are " + "included regardless of the name. Use forward slashes for directories on " + "all platforms (Windows, too). Exclusions are calculated first, inclusions " + "later." + ), + show_default=True, +) +@click.option( + "--exclude", + type=str, + default=DEFAULT_EXCLUDES, + help=( + "A regular expression that matches files and directories that should be " + "excluded on recursive searches. An empty value means no paths are excluded. " + "Use forward slashes for directories on all platforms (Windows, too). " + "Exclusions are calculated first, inclusions later." + ), + show_default=True, +) @click.option( "-q", "--quiet", @@ -153,6 +276,15 @@ class Changed(Enum): "silence those with 2>/dev/null." ), ) +@click.option( + "-v", + "--verbose", + is_flag=True, + help=( + "Also emit messages to stderr about files that were not changed or were " + "ignored due to --exclude=." + ), +) @click.version_option(version=__version__) @click.argument( "src", @@ -160,6 +292,16 @@ class Changed(Enum): type=click.Path( exists=True, file_okay=True, dir_okay=True, readable=True, allow_dash=True ), + is_eager=True, +) +@click.option( + "--config", + type=click.Path( + exists=False, file_okay=True, dir_okay=False, readable=True, allow_dash=False + ), + is_eager=True, + callback=read_pyproject_toml, + help="Read configuration from PATH.", ) @click.pass_context def main( @@ -168,94 +310,135 @@ def main( check: bool, diff: bool, fast: bool, + pyi: bool, + py36: bool, + skip_string_normalization: bool, quiet: bool, - src: List[str], + verbose: bool, + include: str, + exclude: str, + src: Tuple[str], + config: Optional[str], ) -> None: """The uncompromising code formatter.""" - sources: List[Path] = [] + write_back = WriteBack.from_configuration(check=check, diff=diff) + mode = FileMode.from_configuration( + py36=py36, pyi=pyi, skip_string_normalization=skip_string_normalization + ) + if config and verbose: + out(f"Using configuration from {config}.", bold=False, fg="blue") + try: + include_regex = re_compile_maybe_verbose(include) + except re.error: + err(f"Invalid regular expression for include given: {include!r}") + ctx.exit(2) + try: + exclude_regex = re_compile_maybe_verbose(exclude) + except re.error: + err(f"Invalid regular expression for exclude given: {exclude!r}") + ctx.exit(2) + report = Report(check=check, quiet=quiet, verbose=verbose) + root = find_project_root(src) + sources: Set[Path] = set() for s in src: p = Path(s) if p.is_dir(): - sources.extend(gen_python_files_in_dir(p)) - elif p.is_file(): + sources.update( + gen_python_files_in_dir(p, root, include_regex, exclude_regex, report) + ) + elif p.is_file() or s == "-": # if a file was explicitly given, we don't care about its extension - sources.append(p) - elif s == "-": - sources.append(Path("-")) + sources.add(p) else: err(f"invalid path: {s}") - - if check and not diff: - write_back = WriteBack.NO - elif diff: - write_back = WriteBack.DIFF - else: - write_back = WriteBack.YES - report = Report(check=check, quiet=quiet) if len(sources) == 0: + if verbose or not quiet: + out("No paths given. Nothing to do 😴") ctx.exit(0) - return - elif len(sources) == 1: - reformat_one(sources[0], line_length, fast, write_back, report) + 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, line_length, fast, write_back, report, loop, executor + sources=sources, + line_length=line_length, + fast=fast, + write_back=write_back, + mode=mode, + report=report, + loop=loop, + executor=executor, ) ) finally: shutdown(loop) - if not quiet: - out("All done! ✨ 🍰 ✨") - click.echo(str(report)) + if verbose or not quiet: + bang = "💥 💔 💥" if report.return_code else "✨ 🍰 ✨" + out(f"All done! {bang}") + click.secho(str(report), err=True) ctx.exit(report.return_code) def reformat_one( - src: Path, line_length: int, fast: bool, write_back: WriteBack, report: "Report" + src: Path, + line_length: int, + 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`, and `fast` options are passed to :func:`format_file_in_place`. + `write_back`, `fast` and `pyi` options are passed to + :func:`format_file_in_place` or :func:`format_stdin_to_stdout`. """ 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 + line_length=line_length, fast=fast, write_back=write_back, mode=mode ): changed = Changed.YES else: cache: Cache = {} if write_back != WriteBack.DIFF: - cache = read_cache() - src = src.resolve() - if src in cache and cache[src] == get_cache_info(src): + cache = read_cache(line_length, 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 - ) + if changed is not Changed.CACHED and format_file_in_place( + src, + line_length=line_length, + fast=fast, + write_back=write_back, + mode=mode, ): changed = Changed.YES - if write_back != WriteBack.DIFF and changed is not Changed.NO: - write_cache(cache, [src]) + if write_back == WriteBack.YES and changed is not Changed.NO: + write_cache(cache, [src], line_length, mode) report.done(src, changed) except Exception as exc: report.failed(src, str(exc)) async def schedule_formatting( - sources: List[Path], + sources: Set[Path], line_length: int, fast: bool, write_back: WriteBack, + mode: FileMode, report: "Report", loop: BaseEventLoop, executor: Executor, @@ -264,14 +447,14 @@ async def schedule_formatting( (Use ProcessPoolExecutors for actual parallelism.) - `line_length`, `write_back`, and `fast` options are passed to + `line_length`, `write_back`, `fast`, and `pyi` options are passed to :func:`format_file_in_place`. """ cache: Cache = {} if write_back != WriteBack.DIFF: - cache = read_cache() + cache = read_cache(line_length, mode) sources, cached = filter_cached(cache, sources) - for src in cached: + for src in sorted(cached): report.done(src, Changed.CACHED) cancelled = [] formatted = [] @@ -283,36 +466,40 @@ async def schedule_formatting( manager = Manager() lock = manager.Lock() tasks = { - src: loop.run_in_executor( - executor, format_file_in_place, src, line_length, fast, write_back, lock - ) - for src in sources + loop.run_in_executor( + executor, + format_file_in_place, + src, + line_length, + fast, + write_back, + mode, + lock, + ): src + for src in sorted(sources) } - _task_values = list(tasks.values()) + pending: Iterable[asyncio.Task] = tasks.keys() try: - loop.add_signal_handler(signal.SIGINT, cancel, _task_values) - loop.add_signal_handler(signal.SIGTERM, cancel, _task_values) + 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 - await asyncio.wait(_task_values) - for src, task in tasks.items(): - if not task.done(): - report.failed(src, "timed out, cancelling") - task.cancel() - cancelled.append(task) - elif 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) - + 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) if cancelled: await asyncio.gather(*cancelled, loop=loop, return_exceptions=True) - if write_back != WriteBack.DIFF and formatted: - write_cache(cache, formatted) + if write_back == WriteBack.YES and formatted: + write_cache(cache, formatted, line_length, mode) def format_file_in_place( @@ -320,6 +507,7 @@ def format_file_in_place( line_length: int, fast: bool, 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. @@ -327,27 +515,38 @@ def format_file_in_place( If `write_back` is True, write reformatted code back to stdout. `line_length` and `fast` options are passed to :func:`format_file_contents`. """ + if src.suffix == ".pyi": + mode |= FileMode.PYI - with tokenize.open(src) as src_buffer: - src_contents = src_buffer.read() + 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 + src_contents, line_length=line_length, fast=fast, mode=mode ) except NothingChanged: return False if write_back == write_back.YES: - with open(src, "w", encoding=src_buffer.encoding) as f: + with open(src, "w", encoding=encoding, newline=newline) as f: f.write(dst_contents) elif write_back == write_back.DIFF: - src_name = f"{src} (original)" - dst_name = f"{src} (formatted)" + now = datetime.utcnow() + src_name = f"{src}\t{then} +0000" + dst_name = f"{src}\t{now} +0000" diff_contents = diff(src_contents, dst_contents, src_name, dst_name) if lock: lock.acquire() try: - sys.stdout.write(diff_contents) + f = io.TextIOWrapper( + sys.stdout.buffer, + encoding=encoding, + newline=newline, + write_through=True, + ) + f.write(diff_contents) + f.detach() finally: if lock: lock.release() @@ -355,33 +554,47 @@ def format_file_in_place( def format_stdin_to_stdout( - line_length: int, fast: bool, write_back: WriteBack = WriteBack.NO + line_length: int, + fast: bool, + write_back: WriteBack = WriteBack.NO, + mode: FileMode = FileMode.AUTO_DETECT, ) -> bool: """Format file on stdin. Return True if changed. If `write_back` is True, write reformatted code back to stdout. - `line_length` and `fast` arguments are passed to :func:`format_file_contents`. + `line_length`, `fast`, `is_pyi`, and `force_py36` arguments are passed to + :func:`format_file_contents`. """ - src = sys.stdin.read() + 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) + dst = format_file_contents(src, line_length=line_length, fast=fast, mode=mode) return True except NothingChanged: return False finally: + f = io.TextIOWrapper( + sys.stdout.buffer, encoding=encoding, newline=newline, write_through=True + ) if write_back == WriteBack.YES: - sys.stdout.write(dst) + f.write(dst) elif write_back == WriteBack.DIFF: - src_name = " (original)" - dst_name = " (formatted)" - sys.stdout.write(diff(src, dst, src_name, dst_name)) + now = datetime.utcnow() + src_name = f"STDIN\t{then} +0000" + dst_name = f"STDOUT\t{now} +0000" + f.write(diff(src, dst, src_name, dst_name)) + f.detach() def format_file_contents( - src_contents: str, line_length: int, fast: bool + src_contents: str, + *, + line_length: int, + fast: bool, + mode: FileMode = FileMode.AUTO_DETECT, ) -> FileContent: """Reformat contents a file and return new contents. @@ -392,26 +605,35 @@ def format_file_contents( if src_contents.strip() == "": raise NothingChanged - dst_contents = format_str(src_contents, line_length=line_length) + dst_contents = format_str(src_contents, line_length=line_length, 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) + assert_stable(src_contents, dst_contents, line_length=line_length, mode=mode) return dst_contents -def format_str(src_contents: str, line_length: int) -> FileContent: +def format_str( + src_contents: str, line_length: int, *, mode: FileMode = FileMode.AUTO_DETECT +) -> FileContent: """Reformat a string and return new contents. `line_length` determines how many characters per line are allowed. """ src_node = lib2to3_parse(src_contents) dst_contents = "" - lines = LineGenerator() - elt = EmptyLineTracker() - py36 = is_python36(src_node) + 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) + lines = LineGenerator( + remove_u_prefix=py36 or "unicode_literals" in future_imports, + is_pyi=is_pyi, + normalize_strings=normalize_strings, + ) + elt = EmptyLineTracker(is_pyi=is_pyi) empty_line = Line() after = 0 for current_line in lines.visit(src_node): @@ -425,6 +647,23 @@ def format_str(src_contents: str, line_length: int) -> FileContent: return dst_contents +def decode_bytes(src: bytes) -> Tuple[FileContent, Encoding, NewLine]: + """Return a tuple of (decoded_contents, encoding, newline). + + `newline` is either CRLF or LF but `decoded_contents` is decoded with + universal newlines (i.e. only contains LF). + """ + srcbuf = io.BytesIO(src) + encoding, lines = tokenize.detect_encoding(srcbuf.readline) + if not lines: + return "", encoding, "\n" + + newline = "\r\n" if b"\r\n" == lines[0][-2:] else "\n" + srcbuf.seek(0) + with io.TextIOWrapper(srcbuf, encoding) as tiow: + return tiow.read(), encoding, newline + + GRAMMARS = [ pygram.python_grammar_no_print_statement_no_exec_statement, pygram.python_grammar_no_print_statement, @@ -435,9 +674,8 @@ GRAMMARS = [ def lib2to3_parse(src_txt: str) -> Node: """Given a string with source, return the lib2to3 Node.""" grammar = pygram.python_grammar_no_print_statement - if src_txt[-1] != "\n": - nl = "\r\n" if "\r\n" in src_txt[:1024] else "\n" - src_txt += nl + if src_txt[-1:] != "\n": + src_txt += "\n" for grammar in GRAMMARS: drv = driver.Driver(grammar, pytree.convert) try: @@ -553,19 +791,20 @@ COMPARATORS = { token.GREATEREQUAL, } MATH_OPERATORS = { + token.VBAR, + token.CIRCUMFLEX, + token.AMPER, + token.LEFTSHIFT, + token.RIGHTSHIFT, token.PLUS, token.MINUS, token.STAR, token.SLASH, - token.VBAR, - token.AMPER, + token.DOUBLESLASH, token.PERCENT, - token.CIRCUMFLEX, + token.AT, token.TILDE, - token.LEFTSHIFT, - token.RIGHTSHIFT, token.DOUBLESTAR, - token.DOUBLESLASH, } STARS = {token.STAR, token.DOUBLESTAR} VARARGS_PARENTS = { @@ -580,13 +819,64 @@ UNPACKING_PARENTS = { syms.dictsetmaker, syms.listmaker, syms.testlist_gexp, + syms.testlist_star_expr, +} +TEST_DESCENDANTS = { + syms.test, + syms.lambdef, + syms.or_test, + syms.and_test, + syms.not_test, + syms.comparison, + syms.star_expr, + syms.expr, + syms.xor_expr, + syms.and_expr, + syms.shift_expr, + syms.arith_expr, + syms.trailer, + syms.term, + syms.power, +} +ASSIGNMENTS = { + "=", + "+=", + "-=", + "*=", + "@=", + "/=", + "%=", + "&=", + "|=", + "^=", + "<<=", + ">>=", + "**=", + "//=", } COMPREHENSION_PRIORITY = 20 -COMMA_PRIORITY = 10 -LOGIC_PRIORITY = 5 -STRING_PRIORITY = 4 -COMPARATOR_PRIORITY = 3 -MATH_PRIORITY = 1 +COMMA_PRIORITY = 18 +TERNARY_PRIORITY = 16 +LOGIC_PRIORITY = 14 +STRING_PRIORITY = 12 +COMPARATOR_PRIORITY = 10 +MATH_PRIORITIES = { + token.VBAR: 9, + token.CIRCUMFLEX: 8, + token.AMPER: 7, + token.LEFTSHIFT: 6, + token.RIGHTSHIFT: 6, + token.PLUS: 5, + token.MINUS: 5, + token.STAR: 4, + token.SLASH: 4, + token.DOUBLESLASH: 4, + token.PERCENT: 4, + token.AT: 4, + token.TILDE: 3, + token.DOUBLESTAR: 2, +} +DOT_PRIORITY = 1 @dataclass @@ -597,8 +887,8 @@ class BracketTracker: bracket_match: Dict[Tuple[Depth, NodeType], Leaf] = Factory(dict) delimiters: Dict[LeafID, Priority] = Factory(dict) previous: Optional[Leaf] = None - _for_loop_variable: bool = False - _lambda_arguments: bool = False + _for_loop_variable: int = 0 + _lambda_arguments: int = 0 def mark(self, leaf: Leaf) -> None: """Mark `leaf` with bracket-related metadata. Keep track of delimiters. @@ -652,6 +942,17 @@ 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: + """Return the number of delimiters with the given `priority`. + + If no `priority` is passed, defaults to max priority on the line. + """ + if not self.delimiters: + return 0 + + priority = priority or self.max_delimiter_priority() + return sum(1 for p in self.delimiters.values() if p == priority) + def maybe_increment_for_loop_variable(self, leaf: Leaf) -> bool: """In a for loop, or comprehension, the variables are often unpacks. @@ -660,7 +961,7 @@ class BracketTracker: """ if leaf.type == token.NAME and leaf.value == "for": self.depth += 1 - self._for_loop_variable = True + self._for_loop_variable += 1 return True return False @@ -669,7 +970,7 @@ class BracketTracker: """See `maybe_increment_for_loop_variable` above for explanation.""" if self._for_loop_variable and leaf.type == token.NAME and leaf.value == "in": self.depth -= 1 - self._for_loop_variable = False + self._for_loop_variable -= 1 return True return False @@ -682,7 +983,7 @@ class BracketTracker: """ if leaf.type == token.NAME and leaf.value == "lambda": self.depth += 1 - self._lambda_arguments = True + self._lambda_arguments += 1 return True return False @@ -691,11 +992,15 @@ class BracketTracker: """See `maybe_increment_lambda_arguments` above for explanation.""" if self._lambda_arguments and leaf.type == token.COLON: self.depth -= 1 - self._lambda_arguments = False + self._lambda_arguments -= 1 return True return False + def get_open_lsqb(self) -> Optional[Leaf]: + """Return the most recent opening square bracket (if any).""" + return self.bracket_match.get((self.depth - 1, token.RSQB)) + @dataclass class Line: @@ -706,6 +1011,7 @@ class Line: comments: List[Tuple[Index, Leaf]] = Factory(list) bracket_tracker: BracketTracker = Factory(BracketTracker) inside_brackets: bool = False + should_explode: bool = False def append(self, leaf: Leaf, preformatted: bool = False) -> None: """Add a new `leaf` to the end of the line. @@ -721,14 +1027,17 @@ class Line: if not has_value: return + if token.COLON == leaf.type and self.is_class_paren_empty: + del self.leaves[-2:] if self.leaves and not preformatted: # Note: at this point leaf.prefix should be empty except for # imports, for which we only preserve newlines. - leaf.prefix += whitespace(leaf) + leaf.prefix += whitespace( + leaf, complex_subscript=self.is_complex_subscript(leaf) + ) if self.inside_brackets or not preformatted: self.bracket_tracker.mark(leaf) self.maybe_remove_trailing_comma(leaf) - if not self.append_comment(leaf): self.leaves.append(leaf) @@ -773,6 +1082,13 @@ class Line: and self.leaves[0].value == "class" ) + @property + def is_stub_class(self) -> bool: + """Is this line a class definition with a body consisting only of "..."?""" + return self.is_class and self.leaves[-3:] == [ + Leaf(token.DOT, ".") for _ in range(3) + ] + @property def is_def(self) -> bool: """Is this a function definition? (Also returns True for async defs.)""" @@ -785,35 +1101,36 @@ class Line: second_leaf: Optional[Leaf] = self.leaves[1] except IndexError: second_leaf = None - return ( - (first_leaf.type == token.NAME and first_leaf.value == "def") - or ( - first_leaf.type == token.ASYNC - and second_leaf is not None - and second_leaf.type == token.NAME - and second_leaf.value == "def" - ) + return (first_leaf.type == token.NAME and first_leaf.value == "def") or ( + first_leaf.type == token.ASYNC + and second_leaf is not None + and second_leaf.type == token.NAME + and second_leaf.value == "def" ) @property - def is_flow_control(self) -> bool: - """Is this line a flow control statement? + def is_class_paren_empty(self) -> bool: + """Is this a class with no base classes but using parentheses? - Those are `return`, `raise`, `break`, and `continue`. + Those are unnecessary and should be removed. """ return ( bool(self) - and self.leaves[0].type == token.NAME - and self.leaves[0].value in FLOW_CONTROL + and len(self.leaves) == 4 + and self.is_class + and self.leaves[2].type == token.LPAR + and self.leaves[2].value == "(" + and self.leaves[3].type == token.RPAR + and self.leaves[3].value == ")" ) @property - def is_yield(self) -> bool: - """Is this line a yield statement?""" + def is_triple_quoted_string(self) -> bool: + """Is the line a triple quoted string?""" return ( bool(self) - and self.leaves[0].type == token.NAME - and self.leaves[0].value == "yield" + and self.leaves[0].type == token.STRING + and self.leaves[0].value.startswith(('"""', "'''")) ) def contains_standalone_comments(self, depth_limit: int = sys.maxsize) -> bool: @@ -825,6 +1142,13 @@ class Line: return False + def contains_multiline_strings(self) -> bool: + for leaf in self.leaves: + if is_multiline_string(leaf): + return True + + return False + def maybe_remove_trailing_comma(self, closing: Leaf) -> bool: """Remove trailing comma if there is one and it's safe.""" if not ( @@ -844,9 +1168,14 @@ class Line: self.remove_trailing_comma() return True - # For parens let's check if it's safe to remove the comma. If the - # trailing one is the only one, we might mistakenly change a tuple - # into a different type by removing the comma. + # For parens let's check if it's safe to remove the comma. + # Imports are always safe. + if self.is_import: + self.remove_trailing_comma() + return True + + # Otheriwsse, 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 opening = closing.opening_bracket @@ -857,7 +1186,7 @@ class Line: else: return False - for leaf in self.leaves[_opening_index + 1:]: + for leaf in self.leaves[_opening_index + 1 :]: if leaf is closing: break @@ -896,17 +1225,21 @@ class Line: self.comments.append((after, comment)) return True - def comments_after(self, leaf: Leaf) -> Iterator[Leaf]: - """Generate comments that should appear directly after `leaf`.""" - for _leaf_index, _leaf in enumerate(self.leaves): - if leaf is _leaf: - break + def comments_after(self, leaf: Leaf, _index: int = -1) -> Iterator[Leaf]: + """Generate comments that should appear directly after `leaf`. - else: - return + Provide a non-negative leaf `_index` to speed up the function. + """ + if _index == -1: + for _index, _leaf in enumerate(self.leaves): + if leaf is _leaf: + break + + else: + return for index, comment_after in self.comments: - if _leaf_index == index: + if _index == index: yield comment_after def remove_trailing_comma(self) -> None: @@ -918,6 +1251,24 @@ class Line: self.comments[i] = (comma_index - 1, comment) self.leaves.pop() + def is_complex_subscript(self, leaf: Leaf) -> bool: + """Return True iff `leaf` is part of a slice with non-trivial exprs.""" + open_lsqb = ( + leaf if leaf.type == token.LSQB else self.bracket_tracker.get_open_lsqb() + ) + if open_lsqb is None: + return False + + subscript_start = open_lsqb.next_sibling + if ( + isinstance(subscript_start, Node) + and subscript_start.type == syms.subscriptlist + ): + subscript_start = child_towards(subscript_start, leaf) + return subscript_start is not None and any( + n.type in TEST_DESCENDANTS for n in subscript_start.pre_order() + ) + def __str__(self) -> str: """Render the line.""" if not self: @@ -996,6 +1347,8 @@ class EmptyLineTracker: the prefix of the first leaf consists of optional newlines. Those newlines are consumed by `maybe_empty_lines()` and included in the computation. """ + + is_pyi: bool = False previous_line: Optional[Line] = None previous_after: int = 0 previous_defs: List[int] = Factory(list) @@ -1004,8 +1357,7 @@ class EmptyLineTracker: """Return the number of extra empty lines before and after the `current_line`. This is for separating `def`, `async def` and `class` with extra empty - lines (two on module-level), as well as providing an extra empty line - after flow control keywords to make them more prominent. + lines (two on module-level). """ if isinstance(current_line, UnformattedLines): return 0, 0 @@ -1019,7 +1371,7 @@ class EmptyLineTracker: def _maybe_empty_lines(self, current_line: Line) -> Tuple[int, int]: max_allowed = 1 if current_line.depth == 0: - max_allowed = 2 + max_allowed = 1 if self.is_pyi else 2 if current_line.leaves: # Consume the first leaf's extra newlines. first_leaf = current_line.leaves[0] @@ -1031,7 +1383,10 @@ class EmptyLineTracker: depth = current_line.depth while self.previous_defs and self.previous_defs[-1] >= depth: self.previous_defs.pop() - before = 1 if depth else 2 + if self.is_pyi: + before = 0 if depth else 1 + else: + before = 1 if depth else 2 is_decorator = current_line.is_decorator if is_decorator or current_line.is_def or current_line.is_class: if not is_decorator: @@ -1043,6 +1398,11 @@ class EmptyLineTracker: if self.previous_line.is_decorator: return 0, 0 + if self.previous_line.depth < current_line.depth and ( + self.previous_line.is_class or self.previous_line.is_def + ): + return 0, 0 + if ( self.previous_line.is_comment and self.previous_line.depth == current_line.depth @@ -1050,14 +1410,22 @@ class EmptyLineTracker: ): return 0, 0 - newlines = 2 - if current_line.depth: + if self.is_pyi: + if self.previous_line.depth > current_line.depth: + 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: + newlines = 0 + else: + newlines = 1 + else: + newlines = 0 + else: + newlines = 2 + if current_line.depth and newlines: newlines -= 1 return newlines, 0 - if current_line.is_flow_control: - return before, 1 - if ( self.previous_line and self.previous_line.is_import @@ -1068,10 +1436,10 @@ class EmptyLineTracker: if ( self.previous_line - and self.previous_line.is_yield - and (not current_line.is_yield or depth != self.previous_line.depth) + and self.previous_line.is_class + and current_line.is_triple_quoted_string ): - return (before or 1), 0 + return before, 1 return before, 0 @@ -1083,7 +1451,11 @@ class LineGenerator(Visitor[Line]): Note: destroys the tree it's visiting by mutating prefixes of its leaves in ways that will no longer stringify to valid Python code on the tree. """ + + is_pyi: bool = False + normalize_strings: bool = True current_line: Line = Factory(Line) + remove_u_prefix: bool = False def line(self, indent: int = 0, type: Type[Line] = Line) -> Iterator[Line]: """Generate a line. @@ -1150,7 +1522,8 @@ class LineGenerator(Visitor[Line]): else: normalize_prefix(node, inside_brackets=any_open_brackets) - if node.type == token.STRING: + 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) @@ -1182,14 +1555,13 @@ class LineGenerator(Visitor[Line]): """Visit a statement. This implementation is shared for `if`, `while`, `for`, `try`, `except`, - `def`, `with`, `class`, and `assert`. + `def`, `with`, `class`, `assert` and assignments. The relevant Python language `keywords` for a given statement will be NAME leaves within it. This methods puts those on a separate line. - `parens` holds pairs of nodes where invisible parentheses should be put. - Keys hold nodes after which opening parentheses should be put, values - hold nodes before which closing parentheses should be put. + `parens` holds a set of string leaf values immediately after which + invisible parens should be put. """ normalize_invisible_parens(node, parens_after=parens) for child in node.children: @@ -1198,16 +1570,27 @@ class LineGenerator(Visitor[Line]): yield from self.visit(child) + def visit_suite(self, node: Node) -> Iterator[Line]: + """Visit a suite.""" + if self.is_pyi and is_stub_suite(node): + yield from self.visit(node.children[2]) + else: + yield from self.visit_default(node) + def visit_simple_stmt(self, node: Node) -> Iterator[Line]: """Visit a statement without nested statements.""" is_suite_like = node.parent and node.parent.type in STATEMENT if is_suite_like: - yield from self.line(+1) - yield from self.visit_default(node) - yield from self.line(-1) + if self.is_pyi and is_stub_body(node): + yield from self.visit_default(node) + else: + yield from self.line(+1) + yield from self.visit_default(node) + yield from self.line(-1) else: - yield from self.line() + if not self.is_pyi or not node.parent or not is_stub_suite(node.parent): + yield from self.line() yield from self.visit_default(node) def visit_async_stmt(self, node: Node) -> Iterator[Line]: @@ -1231,32 +1614,6 @@ class LineGenerator(Visitor[Line]): yield from self.line() yield from self.visit(child) - def visit_import_from(self, node: Node) -> Iterator[Line]: - """Visit import_from and maybe put invisible parentheses. - - This is separate from `visit_stmt` because import statements don't - support arbitrary atoms and thus handling of parentheses is custom. - """ - check_lpar = False - for index, child in enumerate(node.children): - if check_lpar: - if child.type == token.LPAR: - # make parentheses invisible - child.value = "" # type: ignore - node.children[-1].value = "" # type: ignore - else: - # insert invisible parentheses - node.insert_child(index, Leaf(token.LPAR, "")) - node.append_child(Leaf(token.RPAR, "")) - break - - check_lpar = ( - child.type == token.NAME and child.value == "import" # type: ignore - ) - - for child in node.children: - yield from self.visit(child) - def visit_SEMI(self, leaf: Leaf) -> Iterator[Line]: """Remove a semicolon and put the other statement on a separate line.""" yield from self.line() @@ -1289,7 +1646,9 @@ class LineGenerator(Visitor[Line]): v = self.visit_stmt Ø: Set[str] = set() self.visit_assert_stmt = partial(v, keywords={"assert"}, parens={"assert", ","}) - self.visit_if_stmt = partial(v, keywords={"if", "else", "elif"}, parens={"if"}) + self.visit_if_stmt = partial( + v, keywords={"if", "else", "elif"}, parens={"if", "elif"} + ) self.visit_while_stmt = partial(v, keywords={"while", "else"}, parens={"while"}) self.visit_for_stmt = partial(v, keywords={"for", "else"}, parens={"for", "in"}) self.visit_try_stmt = partial( @@ -1299,6 +1658,9 @@ class LineGenerator(Visitor[Line]): self.visit_with_stmt = partial(v, keywords={"with"}, parens=Ø) self.visit_funcdef = partial(v, keywords={"def"}, parens=Ø) self.visit_classdef = partial(v, keywords={"class"}, parens=Ø) + 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_async_funcdef = self.visit_async_stmt self.visit_decorated = self.visit_decorators @@ -1311,8 +1673,12 @@ BRACKETS = OPENING_BRACKETS | CLOSING_BRACKETS ALWAYS_NO_SPACE = CLOSING_BRACKETS | {token.COMMA, STANDALONE_COMMENT} -def whitespace(leaf: Leaf) -> str: # noqa C901 - """Return whitespace prefix if needed for the given `leaf`.""" +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 + which has non-trivial arguments, like arithmetic expressions or function calls. + """ NO = "" SPACE = " " DOUBLESPACE = " " @@ -1326,7 +1692,11 @@ def whitespace(leaf: Leaf) -> str: # noqa C901 return DOUBLESPACE assert p is not None, f"INTERNAL ERROR: hand-made leaf without parent: {leaf!r}" - if t == token.COLON and p.type not in {syms.subscript, syms.subscriptlist}: + if t == token.COLON and p.type not in { + syms.subscript, + syms.subscriptlist, + syms.sliceop, + }: return NO prev = leaf.prev_sibling @@ -1336,12 +1706,21 @@ def whitespace(leaf: Leaf) -> str: # noqa C901 return NO if t == token.COLON: - return SPACE if prevp.type == token.COMMA else NO + if prevp.type == token.COLON: + return NO + + elif prevp.type != token.COMMA and not complex_subscript: + return NO + + return SPACE if prevp.type == token.EQUAL: if prevp.parent: if prevp.parent.type in { - syms.arglist, syms.argument, syms.parameters, syms.varargslist + syms.arglist, + syms.argument, + syms.parameters, + syms.varargslist, }: return NO @@ -1357,7 +1736,7 @@ def whitespace(leaf: Leaf) -> str: # noqa C901 elif prevp.type == token.COLON: if prevp.parent and prevp.parent.type in {syms.subscript, syms.sliceop}: - return NO + return SPACE if complex_subscript else NO elif ( prevp.parent @@ -1463,7 +1842,7 @@ def whitespace(leaf: Leaf) -> str: # noqa C901 if prev and prev.type == token.LPAR: return NO - elif p.type == syms.subscript: + elif p.type in {syms.subscript, syms.sliceop}: # indexing if not prev: assert p.parent is not None, "subscripts are always parented" @@ -1472,7 +1851,7 @@ def whitespace(leaf: Leaf) -> str: # noqa C901 return NO - else: + elif not complex_subscript: return NO elif p.type == syms.atom: @@ -1494,16 +1873,16 @@ def whitespace(leaf: Leaf) -> str: # noqa C901 prevp_parent = prevp.parent assert prevp_parent is not None - if ( - prevp.type == token.COLON - and prevp_parent.type in {syms.subscript, syms.sliceop} - ): + if prevp.type == token.COLON and prevp_parent.type in { + syms.subscript, + syms.sliceop, + }: return NO elif prevp.type == token.EQUAL and prevp_parent.type == syms.argument: return NO - elif t == token.NAME or t == token.NUMBER: + elif t in {token.NAME, token.NUMBER, token.STRING}: return NO elif p.type == syms.import_from: @@ -1542,6 +1921,14 @@ def preceding_leaf(node: Optional[LN]) -> Optional[Leaf]: return None +def child_towards(ancestor: Node, descendant: LN) -> Optional[LN]: + """Return the child of `ancestor` that contains `descendant`.""" + node: Optional[LN] = descendant + while node and node.parent != ancestor: + node = node.parent + return node + + def is_split_after_delimiter(leaf: Leaf, previous: Leaf = None) -> int: """Return the priority of the `leaf` delimiter, given a line break after it. @@ -1569,12 +1956,20 @@ def is_split_before_delimiter(leaf: Leaf, previous: Leaf = None) -> int: # Don't treat them as a delimiter. return 0 + if ( + leaf.type == token.DOT + and leaf.parent + and leaf.parent.type not in {syms.import_from, syms.dotted_name} + and (previous is None or previous.type in CLOSING_BRACKETS) + ): + return DOT_PRIORITY + if ( leaf.type in MATH_OPERATORS and leaf.parent and leaf.parent.type not in {syms.factor, syms.star_expr} ): - return MATH_PRIORITY + return MATH_PRIORITIES[leaf.type] if leaf.type in COMPARATORS: return COMPARATOR_PRIORITY @@ -1586,29 +1981,60 @@ def is_split_before_delimiter(leaf: Leaf, previous: Leaf = None) -> int: ): return STRING_PRIORITY + if leaf.type != token.NAME: + return 0 + if ( - leaf.type == token.NAME - and leaf.value == "for" + leaf.value == "for" and leaf.parent and leaf.parent.type in {syms.comp_for, syms.old_comp_for} ): return COMPREHENSION_PRIORITY if ( - leaf.type == token.NAME - and leaf.value == "if" + leaf.value == "if" and leaf.parent and leaf.parent.type in {syms.comp_if, syms.old_comp_if} ): return COMPREHENSION_PRIORITY - if leaf.type == token.NAME and leaf.value in LOGIC_OPERATORS and leaf.parent: + if leaf.value in {"if", "else"} and leaf.parent and leaf.parent.type == syms.test: + return TERNARY_PRIORITY + + if leaf.value == "is": + return COMPARATOR_PRIORITY + + if ( + leaf.value == "in" + and leaf.parent + and leaf.parent.type in {syms.comp_op, syms.comparison} + and not ( + previous is not None + and previous.type == token.NAME + and previous.value == "not" + ) + ): + return COMPARATOR_PRIORITY + + if ( + leaf.value == "not" + and leaf.parent + and leaf.parent.type == syms.comp_op + and not ( + previous is not None + and previous.type == token.NAME + and previous.value == "is" + ) + ): + return COMPARATOR_PRIORITY + + if leaf.value in LOGIC_OPERATORS and leaf.parent: return LOGIC_PRIORITY return 0 -def generate_comments(leaf: Leaf) -> Iterator[Leaf]: +def generate_comments(leaf: LN) -> Iterator[Leaf]: """Clean the prefix of the `leaf` and generate comments from it, if any. Comments in lib2to3 are shoved into the whitespace prefix. This happens @@ -1702,10 +2128,8 @@ def split_line( return line_str = str(line).strip("\n") - if ( - len(line_str) <= line_length - and "\n" not in line_str # multiline strings - and not line.contains_standalone_comments() + if not line.should_explode and is_line_short_enough( + line, line_length=line_length, line_str=line_str ): yield line return @@ -1713,10 +2137,24 @@ def split_line( split_funcs: List[SplitFunc] if line.is_def: split_funcs = [left_hand_split] - elif line.inside_brackets: - split_funcs = [delimiter_split, standalone_comment_split, right_hand_split] else: - split_funcs = [right_hand_split] + + def rhs(line: Line, py36: bool = False) -> Iterator[Line]: + for omit in generate_trailers_to_omit(line, line_length): + lines = list(right_hand_split(line, line_length, py36, omit=omit)) + if is_line_short_enough(lines[0], line_length=line_length): + yield from lines + return + + # 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) + + if line.inside_brackets: + split_funcs = [delimiter_split, standalone_comment_split, rhs] + else: + split_funcs = [rhs] for split_func in split_funcs: # We are accumulating lines in `result` because we might want to abort # mission and return the original line in the end, or attempt a different @@ -1745,7 +2183,8 @@ def left_hand_split(line: Line, py36: bool = False) -> 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. + 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) @@ -1783,9 +2222,16 @@ def left_hand_split(line: Line, py36: bool = False) -> Iterator[Line]: def right_hand_split( - line: Line, py36: bool = False, omit: Collection[LeafID] = () + line: Line, line_length: int, py36: bool = False, omit: Collection[LeafID] = () ) -> Iterator[Line]: - """Split line into many lines, starting with the last matching bracket pair.""" + """Split line into many lines, starting with the last matching bracket pair. + + If the split was by optional parentheses, attempt splitting without them, too. + `omit` is a collection of closing bracket IDs that shouldn't be considered for + this 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) @@ -1811,8 +2257,9 @@ def right_hand_split( # Since body is a new indent level, remove spurious leading whitespace. if body_leaves: normalize_prefix(body_leaves[0], inside_brackets=True) - elif not head_leaves: - # No `head` and no `body` means the split failed. `tail` has all content. + if not head_leaves: + # No `head` means the split failed. Either `tail` has all content or + # the matching `opening_bracket` wasn't available on `line` anymore. raise CannotSplit("No brackets found") # Build the new lines. @@ -1821,24 +2268,48 @@ def right_hand_split( result.append(leaf, preformatted=True) for comment_after in line.comments_after(leaf): result.append(comment_after, preformatted=True) - bracket_split_succeeded_or_raise(head, body, tail) assert opening_bracket and closing_bracket + body.should_explode = should_explode(body, opening_bracket) + bracket_split_succeeded_or_raise(head, body, tail) if ( - opening_bracket.type == token.LPAR + # the body shouldn't be exploded + not body.should_explode + # the opening bracket is an optional paren + and opening_bracket.type == token.LPAR and not opening_bracket.value + # the closing bracket is an optional paren and closing_bracket.type == token.RPAR and not closing_bracket.value + # it's not an import (optional parens are the only thing we can split on + # in this case; attempting a split without them is a waste of time) + and not line.is_import + # there are no standalone comments in the body + and not body.contains_standalone_comments(0) + # and we can actually remove the parens + and can_omit_invisible_parens(body, line_length) ): - # These parens were optional. If there aren't any delimiters or standalone - # comments in the body, they were unnecessary and another split without - # them should be attempted. - if not ( - body.bracket_tracker.delimiters or line.contains_standalone_comments(0) - ): - omit = {id(closing_bracket), *omit} - yield from right_hand_split(line, py36=py36, omit=omit) + omit = {id(closing_bracket), *omit} + try: + yield from right_hand_split(line, line_length, py36=py36, omit=omit) return + except CannotSplit: + if not ( + can_be_split(body) + or is_line_short_enough(body, line_length=line_length) + ): + raise CannotSplit( + "Splitting failed, body is still too long and can't be split." + ) + + elif head.contains_multiline_strings() or tail.contains_multiline_strings(): + raise CannotSplit( + "The current optional pair of parentheses is bound to fail to " + "satisfy the splitting algorithm because the head or the tail " + "contains multiline strings which by definition never fit one " + "line." + ) + ensure_visible(opening_bracket) ensure_visible(closing_bracket) for result in (head, body, tail): @@ -1899,14 +2370,16 @@ def delimiter_split(line: Line, py36: bool = False) -> Iterator[Line]: except IndexError: raise CannotSplit("Line empty") - delimiters = line.bracket_tracker.delimiters + bt = line.bracket_tracker try: - delimiter_priority = line.bracket_tracker.max_delimiter_priority( - exclude={id(last_leaf)} - ) + delimiter_priority = bt.max_delimiter_priority(exclude={id(last_leaf)}) except ValueError: raise CannotSplit("No delimiters found") + if delimiter_priority == DOT_PRIORITY: + if bt.delimiter_count_with_priority(delimiter_priority) == 1: + raise CannotSplit("Splitting a single attribute from its owner looks wrong") + current_line = Line(depth=line.depth, inside_brackets=line.inside_brackets) lowest_depth = sys.maxsize trailing_comma_safe = True @@ -1922,19 +2395,18 @@ def delimiter_split(line: Line, py36: bool = False) -> Iterator[Line]: current_line = Line(depth=line.depth, inside_brackets=line.inside_brackets) current_line.append(leaf) - for leaf in line.leaves: + for index, leaf in enumerate(line.leaves): yield from append_to_line(leaf) - for comment_after in line.comments_after(leaf): + for comment_after in line.comments_after(leaf, index): 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) + if leaf.bracket_depth == lowest_depth and is_vararg( + leaf, within=VARARGS_PARENTS ): trailing_comma_safe = trailing_comma_safe and py36 - leaf_priority = delimiters.get(id(leaf)) + leaf_priority = bt.delimiters.get(id(leaf)) if leaf_priority == delimiter_priority: yield current_line @@ -1969,10 +2441,10 @@ def standalone_comment_split(line: Line, py36: bool = False) -> Iterator[Line]: current_line = Line(depth=line.depth, inside_brackets=line.inside_brackets) current_line.append(leaf) - for leaf in line.leaves: + for index, leaf in enumerate(line.leaves): yield from append_to_line(leaf) - for comment_after in line.comments_after(leaf): + for comment_after in line.comments_after(leaf, index): yield from append_to_line(comment_after) if current_line: @@ -2011,6 +2483,22 @@ def normalize_prefix(leaf: Leaf, *, inside_brackets: bool) -> None: leaf.prefix = "" +def normalize_string_prefix(leaf: Leaf, remove_u_prefix: bool = False) -> None: + """Make all string prefixes lowercase. + + If remove_u_prefix is given, also removes any u prefix from the string. + + Note: Mutates its argument. + """ + match = re.match(r"^([furbFURB]*)(.*)$", leaf.value, re.DOTALL) + assert match is not None, f"failed to match string {leaf.value!r}" + orig_prefix = match.group(1) + new_prefix = orig_prefix.lower() + if remove_u_prefix: + new_prefix = new_prefix.replace("u", "") + leaf.value = f"{new_prefix}{match.group(2)}" + + def normalize_string_quotes(leaf: Leaf) -> None: """Prefer double quotes but only if it doesn't cause more escaping. @@ -2040,7 +2528,7 @@ def normalize_string_quotes(leaf: Leaf) -> None: unescaped_new_quote = re.compile(rf"(([^\\]|^)(\\\\)*){new_quote}") escaped_new_quote = re.compile(rf"([^\\]|^)\\(\\\\)*{new_quote}") escaped_orig_quote = re.compile(rf"([^\\]|^)\\(\\\\)*{orig_quote}") - body = leaf.value[first_quote_pos + len(orig_quote):-len(orig_quote)] + body = leaf.value[first_quote_pos + len(orig_quote) : -len(orig_quote)] if "r" in prefix.casefold(): if unescaped_new_quote.search(body): # There's at least one unescaped new_quote in this raw string @@ -2075,31 +2563,42 @@ def normalize_string_quotes(leaf: Leaf) -> None: 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 + should be put. + Standardizes on visible parentheses for single-element tuples, and keeps existing visible parentheses for other tuples and generator expressions. """ + try: + list(generate_comments(node)) + except FormatOff: + return # This `node` has a prefix with `# fmt: off`, don't mess with parens. + check_lpar = False - for child in list(node.children): + for index, child in enumerate(list(node.children)): if check_lpar: if child.type == syms.atom: - if not ( - is_empty_tuple(child) - or is_one_tuple(child) - or max_delimiter_priority_in_atom(child) >= COMMA_PRIORITY - ): - first = child.children[0] - last = child.children[-1] - if first.type == token.LPAR and last.type == token.RPAR: - # make parentheses invisible - first.value = "" # type: ignore - last.value = "" # type: ignore + maybe_make_parens_invisible_in_atom(child) elif is_one_tuple(child): # wrap child in visible parentheses lpar = Leaf(token.LPAR, "(") rpar = Leaf(token.RPAR, ")") - index = child.remove() or 0 + child.remove() node.insert_child(index, Node(syms.atom, [lpar, child, rpar])) - else: + elif node.type == syms.import_from: + # "import from" nodes store parentheses directly as part of + # the statement + if child.type == token.LPAR: + # make parentheses invisible + child.value = "" # type: ignore + node.children[-1].value = "" # type: ignore + elif child.type != token.STAR: + # insert invisible parentheses + node.insert_child(index, Leaf(token.LPAR, "")) + node.append_child(Leaf(token.RPAR, "")) + break + + elif not (isinstance(child, Leaf) and is_multiline_string(child)): # wrap child in invisible parentheses lpar = Leaf(token.LPAR, "") rpar = Leaf(token.RPAR, "") @@ -2109,6 +2608,30 @@ def normalize_invisible_parens(node: Node, parens_after: Set[str]) -> None: 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.""" + if ( + node.type != syms.atom + or is_empty_tuple(node) + or is_one_tuple(node) + or is_yield(node) + or max_delimiter_priority_in_atom(node) >= COMMA_PRIORITY + ): + return False + + first = node.children[0] + last = node.children[-1] + if first.type == token.LPAR and last.type == token.RPAR: + # 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]) + return True + + return False + + def is_empty_tuple(node: LN) -> bool: """Return True if `node` holds an empty tuple.""" return ( @@ -2142,12 +2665,33 @@ def is_one_tuple(node: LN) -> bool: ) +def is_yield(node: LN) -> bool: + """Return True if `node` holds a `yield` or `yield from` expression.""" + if node.type == syms.yield_expr: + return True + + if node.type == token.NAME and node.value == "yield": # type: ignore + return True + + if node.type != syms.atom: + return False + + if len(node.children) != 3: + return False + + lpar, expr, rpar = node.children + if lpar.type == token.LPAR and rpar.type == token.RPAR: + return is_yield(expr) + + return False + + def is_vararg(leaf: Leaf, within: Set[NodeType]) -> bool: """Return True if `leaf` is a star or double star in a vararg or kwarg. If `within` includes VARARGS_PARENTS, this applies to function signatures. - If `within` includes COLLECTION_LIBERALS_PARENTS, it applies to right - hand-side extended iterable unpacking (PEP 3132) and additional unpacking + If `within` includes UNPACKING_PARENTS, it applies to right hand-side + extended iterable unpacking (PEP 3132) and additional unpacking generalizations (PEP 448). """ if leaf.type not in STARS or not leaf.parent: @@ -2165,6 +2709,41 @@ def is_vararg(leaf: Leaf, within: Set[NodeType]) -> bool: return p.type in within +def is_multiline_string(leaf: Leaf) -> bool: + """Return True if `leaf` is a multiline string that actually spans many lines.""" + value = leaf.value.lstrip("furbFURB") + return value[:3] in {'"""', "'''"} and "\n" in value + + +def is_stub_suite(node: Node) -> bool: + """Return True if `node` is a suite with a stub body.""" + if ( + len(node.children) != 4 + or node.children[0].type != token.NEWLINE + or node.children[1].type != token.INDENT + or node.children[3].type != token.DEDENT + ): + return False + + return is_stub_body(node.children[2]) + + +def is_stub_body(node: LN) -> bool: + """Return True if `node` is a simple statement containing an ellipsis.""" + if not isinstance(node, Node) or node.type != syms.simple_stmt: + return False + + if len(node.children) != 2: + return False + + child = node.children[0] + return ( + child.type == syms.atom + and len(child.children) == 3 + and all(leaf == Leaf(token.DOT, ".") for leaf in child.children) + ) + + def max_delimiter_priority_in_atom(node: LN) -> int: """Return maximum delimiter priority inside `node`. @@ -2205,12 +2784,31 @@ def ensure_visible(leaf: Leaf) -> None: leaf.value = ")" +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} + and opening_bracket.value in "[{(" + ): + return False + + try: + last_leaf = line.leaves[-1] + exclude = {id(last_leaf)} if last_leaf.type == token.COMMA else set() + max_priority = line.bracket_tracker.max_delimiter_priority(exclude=exclude) + except (IndexError, ValueError): + return False + + return max_priority == COMMA_PRIORITY + + def is_python36(node: Node) -> bool: """Return True if the current file is using Python 3.6+ features. Currently looking for: - f-strings; and - - trailing commas after * or ** in function signatures. + - trailing commas after * or ** in function signatures and calls. """ for n in node.pre_order(): if n.type == token.STRING: @@ -2219,7 +2817,7 @@ def is_python36(node: Node) -> bool: return True elif ( - n.type == syms.typedargslist + n.type in {syms.typedargslist, syms.arglist} and n.children and n.children[-1].type == token.COMMA ): @@ -2227,35 +2825,171 @@ def is_python36(node: Node) -> bool: if ch.type in STARS: return True + if ch.type == syms.argument: + for argch in ch.children: + if argch.type in STARS: + return True + return False -PYTHON_EXTENSIONS = {".py"} -BLACKLISTED_DIRECTORIES = { - "build", "buck-out", "dist", "_build", ".git", ".hg", ".mypy_cache", ".tox", ".venv" -} +def generate_trailers_to_omit(line: Line, line_length: int) -> Iterator[Set[LeafID]]: + """Generate sets of closing bracket IDs that should be omitted in a RHS. + + Brackets can be omitted if the entire trailer up to and including + a preceding closing bracket fits in one line. + + Yielded sets are cumulative (contain results of previous yields, too). First + set is empty. + """ + + omit: Set[LeafID] = set() + yield omit + 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 + if length > line_length: + break + + has_inline_comment = leaf_length > len(leaf.value) + len(leaf.prefix) + 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 + # pair of brackets was good enough. + 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 -def gen_python_files_in_dir(path: Path) -> Iterator[Path]: - """Generate all files under `path` which aren't under BLACKLISTED_DIRECTORIES - and have one of the PYTHON_EXTENSIONS. + +def get_future_imports(node: Node) -> Set[str]: + """Return a set of __future__ imports in the file.""" + imports = set() + for child in node.children: + if child.type != syms.simple_stmt: + break + first_child = child.children[0] + if isinstance(first_child, Leaf): + # Continue looking if we see a docstring; otherwise stop. + if ( + len(child.children) == 2 + and first_child.type == token.STRING + and child.children[1].type == token.NEWLINE + ): + continue + else: + break + elif first_child.type == syms.import_from: + 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) + else: + break + return imports + + +def gen_python_files_in_dir( + path: Path, + root: Path, + include: Pattern[str], + exclude: Pattern[str], + report: "Report", +) -> Iterator[Path]: + """Generate all files under `path` whose paths are not excluded by the + `exclude` regex, but are included by the `include` regex. + + `report` is where output about exclusions goes. """ + assert root.is_absolute(), f"INTERNAL ERROR: `root` must be absolute but is {root}" for child in path.iterdir(): + normalized_path = "/" + child.resolve().relative_to(root).as_posix() if child.is_dir(): - if child.name in BLACKLISTED_DIRECTORIES: - continue + normalized_path += "/" + exclude_match = exclude.search(normalized_path) + if exclude_match and exclude_match.group(0): + report.path_ignored(child, f"matches the --exclude regular expression") + continue + + if child.is_dir(): + yield from gen_python_files_in_dir(child, root, include, exclude, report) + + elif child.is_file(): + include_match = include.search(normalized_path) + if include_match: + yield child - yield from gen_python_files_in_dir(child) - elif child.suffix in PYTHON_EXTENSIONS: - yield child +@lru_cache() +def find_project_root(srcs: Iterable[str]) -> Path: + """Return a directory containing .git, .hg, or pyproject.toml. + + That directory can be one of the directories passed in `srcs` or their + common parent. + + If no directory in the tree contains a marker that would specify it's the + project root, the root of the file system is returned. + """ + if not srcs: + return Path("/").resolve() + + common_base = min(Path(src).resolve() for src in srcs) + if common_base.is_dir(): + # Append a fake file so `parents` below returns `common_base_dir`, too. + common_base /= "fake-file" + for directory in common_base.parents: + if (directory / ".git").is_dir(): + return directory + + if (directory / ".hg").is_dir(): + return directory + + if (directory / "pyproject.toml").is_file(): + return directory + + return directory @dataclass class Report: """Provides a reformatting counter. Can be rendered with `str(report)`.""" + check: bool = False quiet: bool = False + verbose: bool = False change_count: int = 0 same_count: int = 0 failure_count: int = 0 @@ -2264,11 +2998,11 @@ class Report: """Increment the counter for successful reformatting. Write out a message.""" if changed is Changed.YES: reformatted = "would reformat" if self.check else "reformatted" - if not self.quiet: + if self.verbose or not self.quiet: out(f"{reformatted} {src}") self.change_count += 1 else: - if not self.quiet: + if self.verbose: if changed is Changed.NO: msg = f"{src} already well formatted, good job." else: @@ -2281,6 +3015,10 @@ class Report: err(f"error: cannot format {src}: {message}") self.failure_count += 1 + def path_ignored(self, path: Path, message: str) -> None: + if self.verbose: + out(f"{path} ignored: {message}", bold=False) + @property def return_code(self) -> int: """Return the exit code that the app should use. @@ -2393,9 +3131,11 @@ def assert_equivalent(src: str, dst: str) -> None: ) from None -def assert_stable(src: str, dst: str, line_length: int) -> None: +def assert_stable( + src: str, dst: str, line_length: int, mode: FileMode = FileMode.AUTO_DETECT +) -> None: """Raise AssertionError if `dst` reformats differently the second time.""" - newdst = format_str(dst, line_length=line_length) + newdst = format_str(dst, line_length=line_length, mode=mode) if dst != newdst: log = dump_to_file( diff(src, dst, "source", "first pass"), @@ -2434,7 +3174,7 @@ def diff(a: str, b: str, a_name: str, b_name: str) -> str: ) -def cancel(tasks: List[asyncio.Task]) -> None: +def cancel(tasks: Iterable[asyncio.Task]) -> None: """asyncio signal handler that cancels all `tasks` and reports to stderr.""" err("Aborted!") for task in tasks: @@ -2472,19 +3212,200 @@ def sub_twice(regex: Pattern[str], replacement: str, original: str) -> str: return regex.sub(replacement, regex.sub(replacement, original)) -CACHE_DIR = Path(user_cache_dir("black", version=__version__)) -CACHE_FILE = CACHE_DIR / "cache.pickle" +def re_compile_maybe_verbose(regex: str) -> Pattern[str]: + """Compile a regular expression string in `regex`. + + If it contains newlines, use verbose mode. + """ + if "\n" in regex: + regex = "(?x)" + regex + return re.compile(regex) + + +def enumerate_reversed(sequence: Sequence[T]) -> Iterator[Tuple[Index, T]]: + """Like `reversed(enumerate(sequence))` if that were possible.""" + index = len(sequence) - 1 + for element in reversed(sequence): + yield (index, element) + index -= 1 + + +def enumerate_with_length( + line: Line, reversed: bool = False +) -> Iterator[Tuple[Index, Leaf, int]]: + """Return an enumeration of leaves with their length. + + Stops prematurely on multiline strings and standalone comments. + """ + op = cast( + Callable[[Sequence[Leaf]], Iterator[Tuple[Index, Leaf]]], + enumerate_reversed if reversed else enumerate, + ) + for index, leaf in op(line.leaves): + length = len(leaf.prefix) + len(leaf.value) + if "\n" in leaf.value: + return # Multiline strings, we can't continue. + + comment: Optional[Leaf] + for comment in line.comments_after(leaf, index): + length += len(comment.value) + + yield index, leaf, length -def read_cache() -> Cache: +def is_line_short_enough(line: Line, *, line_length: int, line_str: str = "") -> bool: + """Return True if `line` is no longer than `line_length`. + + Uses the provided `line_str` rendering, if any, otherwise computes a new one. + """ + if not line_str: + line_str = str(line).strip("\n") + return ( + len(line_str) <= line_length + and "\n" not in line_str # multiline strings + and not line.contains_standalone_comments() + ) + + +def can_be_split(line: Line) -> bool: + """Return False if the line cannot be split *for sure*. + + This is not an exhaustive search but a cheap heuristic that we can use to + avoid some unfortunate formattings (mostly around wrapping unsplittable code + in unnecessary parentheses). + """ + leaves = line.leaves + if len(leaves) < 2: + return False + + if leaves[0].type == token.STRING and leaves[1].type == token.DOT: + call_count = 0 + dot_count = 0 + next = leaves[-1] + for leaf in leaves[-2::-1]: + if leaf.type in OPENING_BRACKETS: + if next.type not in CLOSING_BRACKETS: + return False + + call_count += 1 + elif leaf.type == token.DOT: + dot_count += 1 + elif leaf.type == token.NAME: + if not (next.type == token.DOT or next.type in OPENING_BRACKETS): + return False + + elif leaf.type not in CLOSING_BRACKETS: + return False + + if dot_count > 1 and call_count > 1: + return False + + return True + + +def can_omit_invisible_parens(line: Line, line_length: int) -> bool: + """Does `line` have a shape safe to reformat without optional parens around it? + + Returns True for only a subset of potentially nice looking formattings but + the point is to not return false positives that end up producing lines that + are too long. + """ + bt = line.bracket_tracker + if not bt.delimiters: + # Without delimiters the optional parentheses are useless. + return True + + max_priority = bt.max_delimiter_priority() + if bt.delimiter_count_with_priority(max_priority) > 1: + # With more than one delimiter of a kind the optional parentheses read better. + return False + + if max_priority == DOT_PRIORITY: + # A single stranded method call doesn't require optional parentheses. + return True + + assert len(line.leaves) >= 2, "Stranded delimiter" + + first = line.leaves[0] + second = line.leaves[1] + penultimate = line.leaves[-2] + last = line.leaves[-1] + + # With a single delimiter, omit if the expression starts or ends with + # a bracket. + if first.type in OPENING_BRACKETS and second.type not in CLOSING_BRACKETS: + remainder = False + length = 4 * line.depth + for _index, leaf, leaf_length in enumerate_with_length(line): + if leaf.type in CLOSING_BRACKETS and leaf.opening_bracket is first: + remainder = True + if remainder: + length += leaf_length + if length > line_length: + break + + if leaf.type in OPENING_BRACKETS: + # There are brackets we can further split on. + remainder = False + + else: + # checked the entire string and line length wasn't exceeded + if len(line.leaves) == _index + 1: + return True + + # Note: we are not returning False here because a line might have *both* + # a leading opening bracket and a trailing closing bracket. If the + # opening bracket doesn't match our rule, maybe the closing will. + + if ( + last.type == token.RPAR + or last.type == token.RBRACE + or ( + # don't use indexing for omitting optional parentheses; + # it looks weird + last.type == token.RSQB + and last.parent + and last.parent.type != syms.trailer + ) + ): + if penultimate.type in OPENING_BRACKETS: + # Empty brackets don't help. + return False + + if is_multiline_string(first): + # Additional wrapping of a multiline string in this situation is + # unnecessary. + return True + + length = 4 * line.depth + seen_other_brackets = False + for _index, leaf, leaf_length in enumerate_with_length(line): + length += leaf_length + if leaf is last.opening_bracket: + if seen_other_brackets or length <= line_length: + return True + + elif leaf.type in OPENING_BRACKETS: + # There are brackets we can further split on. + seen_other_brackets = True + + return False + + +def get_cache_file(line_length: int, mode: FileMode) -> Path: + return CACHE_DIR / f"cache.{line_length}.{mode.value}.pickle" + + +def read_cache(line_length: int, 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. """ - if not CACHE_FILE.exists(): + cache_file = get_cache_file(line_length, mode) + if not cache_file.exists(): return {} - with CACHE_FILE.open("rb") as fobj: + with cache_file.open("rb") as fobj: try: cache: Cache = pickle.load(fobj) except pickle.UnpicklingError: @@ -2499,31 +3420,32 @@ def get_cache_info(path: Path) -> CacheInfo: return stat.st_mtime, stat.st_size -def filter_cached( - cache: Cache, sources: Iterable[Path] -) -> Tuple[List[Path], List[Path]]: - """Split a list of paths into two. +def filter_cached(cache: Cache, sources: Iterable[Path]) -> Tuple[Set[Path], Set[Path]]: + """Split an iterable of paths in `sources` into two sets. - The first list contains paths of files that modified on disk or are not in the - cache. The other list contains paths to non-modified files. + The first contains paths of files that modified on disk or are not in the + cache. The other contains paths to non-modified files. """ - todo, done = [], [] + todo, done = set(), set() for src in sources: src = src.resolve() if cache.get(src) != get_cache_info(src): - todo.append(src) + todo.add(src) else: - done.append(src) + done.add(src) return todo, done -def write_cache(cache: Cache, sources: List[Path]) -> None: +def write_cache( + cache: Cache, sources: Iterable[Path], line_length: int, mode: FileMode +) -> None: """Update the cache file.""" + cache_file = get_cache_file(line_length, mode) try: if not CACHE_DIR.exists(): CACHE_DIR.mkdir(parents=True) new_cache = {**cache, **{src.resolve(): get_cache_info(src) for src in sources}} - with CACHE_FILE.open("wb") as fobj: + with cache_file.open("wb") as fobj: pickle.dump(new_cache, fobj, protocol=pickle.HIGHEST_PROTOCOL) except OSError: pass