X-Git-Url: https://git.madduck.net/etc/vim.git/blobdiff_plain/c9b73b99ac567ce30c36596371bf0a1fad8191c9..3272bbc8b3e17d229df63daf26d3dce9706cee77:/black.py?ds=sidebyside diff --git a/black.py b/black.py index c2363e4..4599bdd 100644 --- a/black.py +++ b/black.py @@ -2,7 +2,7 @@ import asyncio import pickle from asyncio.base_events import BaseEventLoop from concurrent.futures import Executor, ProcessPoolExecutor -from enum import Enum +from enum import Enum, Flag from functools import partial, wraps import keyword import logging @@ -24,11 +24,13 @@ from typing import ( List, Optional, Pattern, + Sequence, Set, Tuple, Type, TypeVar, Union, + cast, ) from appdirs import user_cache_dir @@ -41,11 +43,13 @@ from blib2to3 import pygram, pytree from blib2to3.pgen2 import driver, token from blib2to3.pgen2.parse import ParseError -__version__ = "18.4a6" + +__version__ = "18.5b1" DEFAULT_LINE_LENGTH = 88 +CACHE_DIR = Path(user_cache_dir("black", version=__version__)) + # types -syms = pygram.python_symbols FileContent = str Encoding = str Depth = int @@ -62,6 +66,9 @@ 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.""" @@ -115,6 +122,13 @@ class Changed(Enum): YES = 2 +class FileMode(Flag): + AUTO_DETECT = 0 + PYTHON36 = 1 + PYI = 2 + NO_STRING_NORMALIZATION = 4 + + @click.command() @click.option( "-l", @@ -152,6 +166,29 @@ class Changed(Enum): "silence those with 2>/dev/null." ), ) +@click.option( + "--pyi", + is_flag=True, + help=( + "Consider all input files typing stubs regardless of file extension " + "(useful when piping source on standard input)." + ), +) +@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( + "-S", + "--skip-string-normalization", + is_flag=True, + help="Don't normalize string quotes or prefixes.", +) @click.version_option(version=__version__) @click.argument( "src", @@ -167,6 +204,9 @@ def main( check: bool, diff: bool, fast: bool, + pyi: bool, + py36: bool, + skip_string_normalization: bool, quiet: bool, src: List[str], ) -> None: @@ -190,6 +230,13 @@ def main( write_back = WriteBack.DIFF else: write_back = WriteBack.YES + mode = FileMode.AUTO_DETECT + if py36: + mode |= FileMode.PYTHON36 + if pyi: + mode |= FileMode.PYI + if skip_string_normalization: + mode |= FileMode.NO_STRING_NORMALIZATION report = Report(check=check, quiet=quiet) if len(sources) == 0: out("No paths given. Nothing to do 😴") @@ -197,14 +244,28 @@ def main( return elif len(sources) == 1: - reformat_one(sources[0], line_length, fast, write_back, report) + reformat_one( + src=sources[0], + 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: @@ -216,36 +277,43 @@ def main( 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(line_length) + cache = read_cache(line_length, mode) src = src.resolve() if src in cache and cache[src] == get_cache_info(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.YES and changed is not Changed.NO: - write_cache(cache, [src], line_length) + write_cache(cache, [src], line_length, mode) report.done(src, changed) except Exception as exc: report.failed(src, str(exc)) @@ -256,6 +324,7 @@ async def schedule_formatting( line_length: int, fast: bool, write_back: WriteBack, + mode: FileMode, report: "Report", loop: BaseEventLoop, executor: Executor, @@ -264,12 +333,12 @@ 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(line_length) + cache = read_cache(line_length, mode) sources, cached = filter_cached(cache, sources) for src in cached: report.done(src, Changed.CACHED) @@ -283,36 +352,40 @@ 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.YES and formatted: - write_cache(cache, formatted, line_length) + write_cache(cache, formatted, line_length, mode) def format_file_in_place( @@ -320,6 +393,7 @@ 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. @@ -327,12 +401,13 @@ 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() 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 @@ -355,17 +430,21 @@ 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() 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: @@ -381,7 +460,11 @@ def format_stdin_to_stdout( 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 +475,35 @@ 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): @@ -622,21 +714,22 @@ LOGIC_PRIORITY = 14 STRING_PRIORITY = 12 COMPARATOR_PRIORITY = 10 MATH_PRIORITIES = { - token.VBAR: 8, - token.CIRCUMFLEX: 7, - token.AMPER: 6, - token.LEFTSHIFT: 5, - token.RIGHTSHIFT: 5, - token.PLUS: 4, - token.MINUS: 4, - token.STAR: 3, - token.SLASH: 3, - token.DOUBLESLASH: 3, - token.PERCENT: 3, - token.AT: 3, - token.TILDE: 2, - token.DOUBLESTAR: 1, + 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 @@ -702,6 +795,17 @@ 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. @@ -760,6 +864,7 @@ 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. @@ -830,6 +935,13 @@ 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.)""" @@ -842,35 +954,11 @@ 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" - ) - ) - - @property - def is_flow_control(self) -> bool: - """Is this line a flow control statement? - - Those are `return`, `raise`, `break`, and `continue`. - """ - return ( - bool(self) - and self.leaves[0].type == token.NAME - and self.leaves[0].value in FLOW_CONTROL - ) - - @property - def is_yield(self) -> bool: - """Is this line a yield statement?""" - return ( - bool(self) - and self.leaves[0].type == token.NAME - and self.leaves[0].value == "yield" + 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 @@ -889,6 +977,15 @@ class Line: and self.leaves[3].value == ")" ) + @property + def is_triple_quoted_string(self) -> bool: + """Is the line a triple quoted string?""" + return ( + bool(self) + and self.leaves[0].type == token.STRING + and self.leaves[0].value.startswith(('"""', "'''")) + ) + def contains_standalone_comments(self, depth_limit: int = sys.maxsize) -> bool: """If so, needs to be split before emitting.""" for leaf in self.leaves: @@ -974,17 +1071,21 @@ 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: @@ -1010,9 +1111,8 @@ class Line: 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()) + return subscript_start is not None and any( + n.type in TEST_DESCENDANTS for n in subscript_start.pre_order() ) def __str__(self) -> str: @@ -1093,6 +1193,8 @@ 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) @@ -1101,8 +1203,7 @@ 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 @@ -1116,7 +1217,7 @@ 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] @@ -1128,7 +1229,10 @@ 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: @@ -1140,6 +1244,11 @@ 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 @@ -1147,8 +1256,19 @@ 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 @@ -1160,6 +1280,13 @@ class EmptyLineTracker: ): return (before or 1), 0 + if ( + self.previous_line + and self.previous_line.is_class + and current_line.is_triple_quoted_string + ): + return before, 1 + return before, 0 @@ -1170,7 +1297,11 @@ 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. @@ -1237,7 +1368,8 @@ 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) @@ -1274,7 +1406,7 @@ class LineGenerator(Visitor[Line]): 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 a set of string leaf values immeditely after which + `parens` holds a set of string leaf values immediately after which invisible parens should be put. """ normalize_invisible_parens(node, parens_after=parens) @@ -1284,16 +1416,27 @@ 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]: @@ -1317,32 +1460,6 @@ 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() @@ -1375,7 +1492,9 @@ 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( @@ -1387,6 +1506,7 @@ class LineGenerator(Visitor[Line]): 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 @@ -1418,10 +1538,11 @@ def whitespace(leaf: Leaf, *, complex_subscript: bool) -> 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, syms.sliceop} - ): + if t == token.COLON and p.type not in { + syms.subscript, + syms.subscriptlist, + syms.sliceop, + }: return NO prev = leaf.prev_sibling @@ -1442,7 +1563,10 @@ def whitespace(leaf: Leaf, *, complex_subscript: bool) -> str: # noqa C901 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 @@ -1595,10 +1719,10 @@ def whitespace(leaf: Leaf, *, complex_subscript: bool) -> 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: @@ -1678,6 +1802,14 @@ 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 @@ -1695,37 +1827,60 @@ 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.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.type == token.NAME - and leaf.value in {"if", "else"} + leaf.value == "in" and leaf.parent - and leaf.parent.type == syms.test + 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 TERNARY_PRIORITY + return COMPARATOR_PRIORITY - if leaf.type == token.NAME and leaf.value in LOGIC_OPERATORS and leaf.parent: + 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 @@ -1819,10 +1974,8 @@ 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 @@ -1830,12 +1983,24 @@ def split_line( split_funcs: List[SplitFunc] if line.is_def: split_funcs = [left_hand_split] - elif line.is_import: - split_funcs = [explode_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 @@ -1903,11 +2068,15 @@ 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. 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) @@ -1934,8 +2103,9 @@ 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. @@ -1953,22 +2123,23 @@ def right_hand_split( # the closing bracket is an optional paren and closing_bracket.type == token.RPAR and not closing_bracket.value - # there are no delimiters or standalone comments in the body - and not body.bracket_tracker.delimiters + # there are no standalone comments in the body and not line.contains_standalone_comments(0) # and 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 ): omit = {id(closing_bracket), *omit} - try: - yield from right_hand_split(line, py36=py36, omit=omit) - return - except CannotSplit: - pass + if can_omit_invisible_parens(body, line_length): + try: + yield from right_hand_split(line, line_length, py36=py36, omit=omit) + return + except CannotSplit: + pass ensure_visible(opening_bracket) ensure_visible(closing_bracket) + body.should_explode = should_explode(body, opening_bracket) for result in (head, body, tail): if result: yield result @@ -2027,14 +2198,16 @@ 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 @@ -2050,19 +2223,18 @@ 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 @@ -2097,36 +2269,16 @@ 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: yield current_line -def explode_split( - line: Line, py36: bool = False, omit: Collection[LeafID] = () -) -> Iterator[Line]: - """Split by rightmost bracket and immediately split contents by a delimiter.""" - new_lines = list(right_hand_split(line, py36, omit)) - if len(new_lines) != 3: - yield from new_lines - return - - yield new_lines[0] - - try: - yield from delimiter_split(new_lines[1], py36) - - except CannotSplit: - yield new_lines[1] - - yield new_lines[2] - - def is_import(leaf: Leaf) -> bool: """Return True if the given leaf starts an import statement.""" p = leaf.parent @@ -2159,6 +2311,22 @@ 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. @@ -2229,8 +2397,13 @@ def normalize_invisible_parens(node: Node, parens_after: Set[str]) -> None: 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: maybe_make_parens_invisible_in_atom(child) @@ -2238,9 +2411,22 @@ def normalize_invisible_parens(node: Node, parens_after: Set[str]) -> None: # 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, "") @@ -2256,6 +2442,7 @@ 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 max_delimiter_priority_in_atom(node) >= COMMA_PRIORITY ): return False @@ -2306,12 +2493,33 @@ 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: @@ -2329,6 +2537,41 @@ 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`. @@ -2369,6 +2612,25 @@ 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. @@ -2399,9 +2661,106 @@ def is_python36(node: Node) -> bool: return False -PYTHON_EXTENSIONS = {".py"} +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 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 + + +PYTHON_EXTENSIONS = {".py", ".pyi"} BLACKLISTED_DIRECTORIES = { - "build", "buck-out", "dist", "_build", ".git", ".hg", ".mypy_cache", ".tox", ".venv" + "build", + "buck-out", + "dist", + "_build", + ".git", + ".hg", + ".mypy_cache", + ".tox", + ".venv", } @@ -2416,13 +2775,14 @@ def gen_python_files_in_dir(path: Path) -> Iterator[Path]: yield from gen_python_files_in_dir(child) - elif child.suffix in PYTHON_EXTENSIONS: + elif child.is_file() and child.suffix in PYTHON_EXTENSIONS: yield child @dataclass class Report: """Provides a reformatting counter. Can be rendered with `str(report)`.""" + check: bool = False quiet: bool = False change_count: int = 0 @@ -2562,9 +2922,11 @@ 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"), @@ -2603,7 +2965,7 @@ 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: @@ -2641,19 +3003,155 @@ 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__)) +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 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_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 -def get_cache_file(line_length: int) -> Path: - return CACHE_DIR / f"cache.{line_length}.pickle" + 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 -def read_cache(line_length: int) -> Cache: + 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: + pyi = bool(mode & FileMode.PYI) + py36 = bool(mode & FileMode.PYTHON36) + return ( + CACHE_DIR + / f"cache.{line_length}{'.pyi' if pyi else ''}{'.py36' if py36 else ''}.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. """ - cache_file = get_cache_file(line_length) + cache_file = get_cache_file(line_length, mode) if not cache_file.exists(): return {} @@ -2690,9 +3188,11 @@ def filter_cached( return todo, done -def write_cache(cache: Cache, sources: List[Path], line_length: int) -> None: +def write_cache( + cache: Cache, sources: List[Path], line_length: int, mode: FileMode +) -> None: """Update the cache file.""" - cache_file = get_cache_file(line_length) + cache_file = get_cache_file(line_length, mode) try: if not CACHE_DIR.exists(): CACHE_DIR.mkdir(parents=True)