import sys
import tempfile
import tokenize
+import traceback
from typing import (
Any,
Callable,
from attr import dataclass, evolve, Factory
import click
import toml
+from typed_ast import ast3, ast27
# lib2to3 fork
from blib2to3.pytree import Node, Leaf, type_repr
NUMERIC_UNDERSCORES = 3
TRAILING_COMMA_IN_CALL = 4
TRAILING_COMMA_IN_DEF = 5
+ # The following two feature-flags are mutually exclusive, and exactly one should be
+ # set for every version of python.
+ ASYNC_IDENTIFIERS = 6
+ ASYNC_KEYWORDS = 7
VERSION_TO_FEATURES: Dict[TargetVersion, Set[Feature]] = {
- TargetVersion.PY27: set(),
- TargetVersion.PY33: {Feature.UNICODE_LITERALS},
- TargetVersion.PY34: {Feature.UNICODE_LITERALS},
- TargetVersion.PY35: {Feature.UNICODE_LITERALS, Feature.TRAILING_COMMA_IN_CALL},
+ TargetVersion.PY27: {Feature.ASYNC_IDENTIFIERS},
+ TargetVersion.PY33: {Feature.UNICODE_LITERALS, Feature.ASYNC_IDENTIFIERS},
+ TargetVersion.PY34: {Feature.UNICODE_LITERALS, Feature.ASYNC_IDENTIFIERS},
+ TargetVersion.PY35: {
+ Feature.UNICODE_LITERALS,
+ Feature.TRAILING_COMMA_IN_CALL,
+ Feature.ASYNC_IDENTIFIERS,
+ },
TargetVersion.PY36: {
Feature.UNICODE_LITERALS,
Feature.F_STRINGS,
Feature.NUMERIC_UNDERSCORES,
Feature.TRAILING_COMMA_IN_CALL,
Feature.TRAILING_COMMA_IN_DEF,
+ Feature.ASYNC_IDENTIFIERS,
},
TargetVersion.PY37: {
Feature.UNICODE_LITERALS,
Feature.NUMERIC_UNDERSCORES,
Feature.TRAILING_COMMA_IN_CALL,
Feature.TRAILING_COMMA_IN_DEF,
+ Feature.ASYNC_KEYWORDS,
},
TargetVersion.PY38: {
Feature.UNICODE_LITERALS,
Feature.NUMERIC_UNDERSCORES,
Feature.TRAILING_COMMA_IN_CALL,
Feature.TRAILING_COMMA_IN_DEF,
+ Feature.ASYNC_KEYWORDS,
},
}
@click.command(context_settings=dict(help_option_names=["-h", "--help"]))
+@click.option("-c", "--code", type=str, help="Format the code passed in as a string.")
@click.option(
"-l",
"--line-length",
"--quiet",
is_flag=True,
help=(
- "Don't emit non-error messages to stderr. Errors are still emitted, "
+ "Don't emit non-error messages to stderr. Errors are still emitted; "
"silence those with 2>/dev/null."
),
)
@click.pass_context
def main(
ctx: click.Context,
+ code: Optional[str],
line_length: int,
target_version: List[TargetVersion],
check: bool,
)
if config and verbose:
out(f"Using configuration from {config}.", bold=False, fg="blue")
+ if code is not None:
+ print(format_str(code, mode=mode))
+ ctx.exit(0)
try:
include_regex = re_compile_maybe_verbose(include)
except re.error:
report=report,
)
else:
- loop = asyncio.get_event_loop()
- executor = ProcessPoolExecutor(max_workers=os.cpu_count())
- try:
- loop.run_until_complete(
- schedule_formatting(
- sources=sources,
- fast=fast,
- write_back=write_back,
- mode=mode,
- report=report,
- loop=loop,
- executor=executor,
- )
- )
- finally:
- shutdown(loop)
+ reformat_many(
+ sources=sources, fast=fast, write_back=write_back, mode=mode, report=report
+ )
+
if verbose or not quiet:
- bang = "💥 💔 💥" if report.return_code else "✨ 🍰 ✨"
- out(f"All done! {bang}")
+ out("Oh no! 💥 💔 💥" if report.return_code else "All done! ✨ 🍰 ✨")
click.secho(str(report), err=True)
ctx.exit(report.return_code)
) -> None:
"""Reformat a single file under `src` without spawning child processes.
- If `quiet` is True, non-error messages are not output. `line_length`,
- `write_back`, `fast` and `pyi` options are passed to
+ `fast`, `write_back`, and `mode` options are passed to
:func:`format_file_in_place` or :func:`format_stdin_to_stdout`.
"""
try:
report.failed(src, str(exc))
+def reformat_many(
+ sources: Set[Path],
+ fast: bool,
+ write_back: WriteBack,
+ mode: FileMode,
+ report: "Report",
+) -> None:
+ """Reformat multiple files using a ProcessPoolExecutor."""
+ loop = asyncio.get_event_loop()
+ worker_count = os.cpu_count()
+ if sys.platform == "win32":
+ # Work around https://bugs.python.org/issue26903
+ worker_count = min(worker_count, 61)
+ executor = ProcessPoolExecutor(max_workers=worker_count)
+ try:
+ loop.run_until_complete(
+ schedule_formatting(
+ sources=sources,
+ fast=fast,
+ write_back=write_back,
+ mode=mode,
+ report=report,
+ loop=loop,
+ executor=executor,
+ )
+ )
+ finally:
+ shutdown(loop)
+
+
async def schedule_formatting(
sources: Set[Path],
fast: bool,
manager = Manager()
lock = manager.Lock()
tasks = {
- loop.run_in_executor(
- executor, format_file_in_place, src, fast, mode, write_back, lock
+ asyncio.ensure_future(
+ loop.run_in_executor(
+ executor, format_file_in_place, src, fast, mode, write_back, lock
+ )
): src
for src in sorted(sources)
}
- pending: Iterable[asyncio.Task] = tasks.keys()
+ pending: Iterable[asyncio.Future] = tasks.keys()
try:
loop.add_signal_handler(signal.SIGINT, cancel, pending)
loop.add_signal_handler(signal.SIGTERM, cancel, pending)
If `write_back` is DIFF, write a diff to stdout. If it is YES, write reformatted
code to the file.
- `line_length` and `fast` options are passed to :func:`format_file_contents`.
+ `mode` and `fast` options are passed to :func:`format_file_contents`.
"""
if src.suffix == ".pyi":
mode = evolve(mode, is_pyi=True)
If `fast` is False, additionally confirm that the reformatted code is
valid by calling :func:`assert_equivalent` and :func:`assert_stable` on it.
- `line_length` is passed to :func:`format_str`.
+ `mode` is passed to :func:`format_str`.
"""
if src_contents.strip() == "":
raise NothingChanged
def format_str(src_contents: str, *, mode: FileMode) -> FileContent:
"""Reformat a string and return new contents.
- `line_length` determines how many characters per line are allowed.
+ `mode` determines formatting options, such as how many characters per line are
+ allowed.
"""
src_node = lib2to3_parse(src_contents.lstrip(), mode.target_versions)
- dst_contents = ""
+ dst_contents = []
future_imports = get_future_imports(src_node)
if mode.target_versions:
versions = mode.target_versions
}
for current_line in lines.visit(src_node):
for _ in range(after):
- dst_contents += str(empty_line)
+ dst_contents.append(str(empty_line))
before, after = elt.maybe_empty_lines(current_line)
for _ in range(before):
- dst_contents += str(empty_line)
+ dst_contents.append(str(empty_line))
for line in split_line(
current_line, line_length=mode.line_length, features=split_line_features
):
- dst_contents += str(line)
- return dst_contents
+ dst_contents.append(str(line))
+ return "".join(dst_contents)
def decode_bytes(src: bytes) -> Tuple[FileContent, Encoding, NewLine]:
if not target_versions:
# No target_version specified, so try all grammars.
return [
+ # Python 3.7+
+ pygram.python_grammar_no_print_statement_no_exec_statement_async_keywords,
+ # Python 3.0-3.6
pygram.python_grammar_no_print_statement_no_exec_statement,
+ # Python 2.7 with future print_function import
pygram.python_grammar_no_print_statement,
+ # Python 2.7
pygram.python_grammar,
]
elif all(version.is_python2() for version in target_versions):
# Python 2-only code, so try Python 2 grammars.
- return [pygram.python_grammar_no_print_statement, pygram.python_grammar]
+ return [
+ # Python 2.7 with future print_function import
+ pygram.python_grammar_no_print_statement,
+ # Python 2.7
+ pygram.python_grammar,
+ ]
else:
# Python 3-compatible code, so only try Python 3 grammar.
- return [pygram.python_grammar_no_print_statement_no_exec_statement]
+ grammars = []
+ # If we have to parse both, try to parse async as a keyword first
+ if not supports_feature(target_versions, Feature.ASYNC_IDENTIFIERS):
+ # Python 3.7+
+ grammars.append(
+ pygram.python_grammar_no_print_statement_no_exec_statement_async_keywords # noqa: B950
+ )
+ if not supports_feature(target_versions, Feature.ASYNC_KEYWORDS):
+ # Python 3.0-3.6
+ grammars.append(pygram.python_grammar_no_print_statement_no_exec_statement)
+ # At least one of the above branches must have been taken, because every Python
+ # version has exactly one of the two 'ASYNC_*' flags
+ return grammars
def lib2to3_parse(src_txt: str, target_versions: Iterable[TargetVersion] = ()) -> Node:
"""Return True if there is an yet unmatched open bracket on the line."""
return bool(self.bracket_match)
- def max_delimiter_priority(self, exclude: Iterable[LeafID] = ()) -> int:
+ def max_delimiter_priority(self, exclude: Iterable[LeafID] = ()) -> Priority:
"""Return the highest priority of a delimiter found on the line.
Values are consistent with what `is_split_*_delimiter()` return.
"""
return max(v for k, v in self.delimiters.items() if k not in exclude)
- def delimiter_count_with_priority(self, priority: int = 0) -> int:
+ def delimiter_count_with_priority(self, priority: Priority = 0) -> int:
"""Return the number of delimiters with the given `priority`.
If no `priority` is passed, defaults to max priority on the line.
try:
last_leaf = self.leaves[-1]
ignored_ids.add(id(last_leaf))
- if last_leaf.type == token.COMMA:
- # When trailing commas are inserted by Black for consistency, comments
- # after the previous last element are not moved (they don't have to,
- # rendering will still be correct). So we ignore trailing commas.
+ if last_leaf.type == token.COMMA or (
+ last_leaf.type == token.RPAR and not last_leaf.value
+ ):
+ # When trailing commas or optional parens are inserted by Black for
+ # consistency, comments after the previous last element are not moved
+ # (they don't have to, rendering will still be correct). So we ignore
+ # trailing commas and invisible.
last_leaf = self.leaves[-2]
ignored_ids.add(id(last_leaf))
except IndexError:
bracket_depth = leaf.bracket_depth
if bracket_depth == depth and leaf.type == token.COMMA:
commas += 1
- if leaf.parent and leaf.parent.type == syms.arglist:
+ if leaf.parent and leaf.parent.type in {
+ syms.arglist,
+ syms.typedargslist,
+ }:
commas += 1
break
comment.prefix = ""
return False
- self.comments.setdefault(id(self.leaves[-1]), []).append(comment)
+ last_leaf = self.leaves[-1]
+ if (
+ last_leaf.type == token.RPAR
+ and not last_leaf.value
+ and last_leaf.parent
+ and len(list(last_leaf.parent.leaves())) <= 3
+ and not is_type_comment(comment)
+ ):
+ # Comments on an optional parens wrapping a single leaf should belong to
+ # the wrapped node except if it's a type comment. Pinning the comment like
+ # this avoids unstable formatting caused by comment migration.
+ if len(self.leaves) < 2:
+ comment.type = STANDALONE_COMMENT
+ comment.prefix = ""
+ return False
+ last_leaf = self.leaves[-2]
+ self.comments.setdefault(id(last_leaf), []).append(comment)
return True
def comments_after(self, leaf: Leaf) -> List[Leaf]:
self.current_line.append(node)
yield from super().visit_default(node)
+ def visit_atom(self, node: Node) -> Iterator[Line]:
+ # Always make parentheses invisible around a single node, because it should
+ # not be needed (except in the case of yield, where removing the parentheses
+ # produces a SyntaxError).
+ if (
+ len(node.children) == 3
+ and isinstance(node.children[0], Leaf)
+ and node.children[0].type == token.LPAR
+ and isinstance(node.children[2], Leaf)
+ and node.children[2].type == token.RPAR
+ and isinstance(node.children[1], Leaf)
+ and not (
+ node.children[1].type == token.NAME
+ and node.children[1].value == "yield"
+ )
+ ):
+ node.children[0].value = ""
+ node.children[2].value = ""
+ yield from super().visit_default(node)
+
def visit_INDENT(self, node: Node) -> Iterator[Line]:
"""Increase indentation level, maybe yield a line."""
# In blib2to3 INDENT never holds comments.
return container
-def is_split_after_delimiter(leaf: Leaf, previous: Optional[Leaf] = None) -> int:
+def is_split_after_delimiter(leaf: Leaf, previous: Optional[Leaf] = None) -> Priority:
"""Return the priority of the `leaf` delimiter, given a line break after it.
The delimiter priorities returned here are from those delimiters that would
return 0
-def is_split_before_delimiter(leaf: Leaf, previous: Optional[Leaf] = None) -> int:
+def is_split_before_delimiter(leaf: Leaf, previous: Optional[Leaf] = None) -> Priority:
"""Return the priority of the `leaf` delimiter, given a line break before it.
The delimiter priorities returned here are from those delimiters that would
consumed = 0
nlines = 0
+ ignored_lines = 0
for index, line in enumerate(prefix.split("\n")):
consumed += len(line) + 1 # adding the length of the split '\n'
line = line.lstrip()
if not line:
nlines += 1
if not line.startswith("#"):
+ # Escaped newlines outside of a comment are not really newlines at
+ # all. We treat a single-line comment following an escaped newline
+ # as a simple trailing comment.
+ if line.endswith("\\"):
+ ignored_lines += 1
continue
- if index == 0 and not is_endmarker:
+ if index == ignored_lines and not is_endmarker:
comment_type = token.COMMENT # simple trailing comment
else:
comment_type = STANDALONE_COMMENT
if leaves:
# Since body is a new indent level, remove spurious leading whitespace.
normalize_prefix(leaves[0], inside_brackets=True)
- # Ensure a trailing comma when expected.
- if original.is_import:
- if leaves[-1].type != token.COMMA:
- leaves.append(Leaf(token.COMMA, ","))
+ # Ensure a trailing comma for imports and standalone function arguments, but
+ # be careful not to add one after any comments.
+ no_commas = original.is_def and not any(
+ l.type == token.COMMA for l in leaves
+ )
+
+ if original.is_import or no_commas:
+ for i in range(len(leaves) - 1, -1, -1):
+ if leaves[i].type == STANDALONE_COMMENT:
+ continue
+ elif leaves[i].type == token.COMMA:
+ break
+ else:
+ leaves.insert(i + 1, Leaf(token.COMMA, ","))
+ break
# Populate the line
for leaf in leaves:
result.append(leaf, preformatted=True)
new_body = sub_twice(escaped_orig_quote, rf"\1\2{orig_quote}", new_body)
new_body = sub_twice(unescaped_new_quote, rf"\1\\{new_quote}", new_body)
if "f" in prefix.casefold():
- matches = re.findall(r"[^{]\{(.*?)\}[^}]", new_body)
+ matches = re.findall(
+ r"""
+ (?:[^{]|^)\{ # start of the string or a non-{ followed by a single {
+ ([^{].*?) # contents of the brackets except if begins with {{
+ \}(?:[^}]|$) # A } followed by end of the string or a non-}
+ """,
+ new_body,
+ re.VERBOSE,
+ )
for m in matches:
if "\\" in str(m):
# Do not introduce backslashes in interpolated expressions
def normalize_invisible_parens(node: Node, parens_after: Set[str]) -> None:
"""Make existing optional parentheses invisible or create new ones.
- `parens_after` is a set of string leaf values immeditely after which parens
+ `parens_after` is a set of string leaf values immediately after which parens
should be put.
Standardizes on visible parentheses for single-element tuples, and keeps
check_lpar = False
for index, child in enumerate(list(node.children)):
+ # Add parentheses around long tuple unpacking in assignments.
+ if (
+ index == 0
+ and isinstance(child, Node)
+ and child.type == syms.testlist_star_expr
+ ):
+ check_lpar = True
+
if check_lpar:
if child.type == syms.atom:
- if maybe_make_parens_invisible_in_atom(child):
+ if maybe_make_parens_invisible_in_atom(child, parent=node):
lpar = Leaf(token.LPAR, "")
rpar = Leaf(token.RPAR, "")
index = child.remove() or 0
lpar = Leaf(token.LPAR, "")
rpar = Leaf(token.RPAR, "")
index = child.remove() or 0
- node.insert_child(index, Node(syms.atom, [lpar, child, rpar]))
+ prefix = child.prefix
+ child.prefix = ""
+ new_child = Node(syms.atom, [lpar, child, rpar])
+ new_child.prefix = prefix
+ node.insert_child(index, new_child)
check_lpar = isinstance(child, Leaf) and child.value in parens_after
container = container.next_sibling
-def maybe_make_parens_invisible_in_atom(node: LN) -> bool:
+def maybe_make_parens_invisible_in_atom(node: LN, parent: LN) -> bool:
"""If it's safe, make the parens in the atom `node` invisible, recursively.
Returns whether the node should itself be wrapped in invisible parentheses.
node.type != syms.atom
or is_empty_tuple(node)
or is_one_tuple(node)
- or is_yield(node)
+ or (is_yield(node) and parent.type != syms.expr_stmt)
or max_delimiter_priority_in_atom(node) >= COMMA_PRIORITY
):
return False
first.value = "" # type: ignore
last.value = "" # type: ignore
if len(node.children) > 1:
- maybe_make_parens_invisible_in_atom(node.children[1])
+ maybe_make_parens_invisible_in_atom(node.children[1], parent=parent)
return False
return True
)
-def max_delimiter_priority_in_atom(node: LN) -> int:
+def max_delimiter_priority_in_atom(node: LN) -> Priority:
"""Return maximum delimiter priority inside `node`.
This is specific to atoms with contents contained in a pair of parentheses.
return ", ".join(report) + "."
+def parse_ast(src: str) -> Union[ast3.AST, ast27.AST]:
+ for feature_version in (7, 6):
+ try:
+ return ast3.parse(src, feature_version=feature_version)
+ except SyntaxError:
+ continue
+
+ return ast27.parse(src)
+
+
def assert_equivalent(src: str, dst: str) -> None:
"""Raise AssertionError if `src` and `dst` aren't equivalent."""
- import ast
- import traceback
-
- def _v(node: ast.AST, depth: int = 0) -> Iterator[str]:
+ def _v(node: Union[ast3.AST, ast27.AST], depth: int = 0) -> Iterator[str]:
"""Simple visitor generating strings to compare ASTs by content."""
yield f"{' ' * depth}{node.__class__.__name__}("
for field in sorted(node._fields):
+ # TypeIgnore has only one field 'lineno' which breaks this comparison
+ if isinstance(node, (ast3.TypeIgnore, ast27.TypeIgnore)):
+ break
+
+ # Ignore str kind which is case sensitive / and ignores unicode_literals
+ if isinstance(node, (ast3.Str, ast27.Str, ast3.Bytes)) and field == "kind":
+ continue
+
try:
value = getattr(node, field)
except AttributeError:
# parentheses and they change the AST.
if (
field == "targets"
- and isinstance(node, ast.Delete)
- and isinstance(item, ast.Tuple)
+ and isinstance(node, (ast3.Delete, ast27.Delete))
+ and isinstance(item, (ast3.Tuple, ast27.Tuple))
):
for item in item.elts:
yield from _v(item, depth + 2)
- elif isinstance(item, ast.AST):
+ elif isinstance(item, (ast3.AST, ast27.AST)):
yield from _v(item, depth + 2)
- elif isinstance(value, ast.AST):
+ elif isinstance(value, (ast3.AST, ast27.AST)):
yield from _v(value, depth + 2)
else:
yield f"{' ' * depth}) # /{node.__class__.__name__}"
try:
- src_ast = ast.parse(src)
+ src_ast = parse_ast(src)
except Exception as exc:
- major, minor = sys.version_info[:2]
raise AssertionError(
- f"cannot use --safe with this file; failed to parse source file "
- f"with Python {major}.{minor}'s builtin AST. Re-run with --fast "
- f"or stop using deprecated Python 2 syntax. AST error message: {exc}"
+ f"cannot use --safe with this file; failed to parse source file. "
+ f"AST error message: {exc}"
)
try:
- dst_ast = ast.parse(dst)
+ dst_ast = parse_ast(dst)
except Exception as exc:
log = dump_to_file("".join(traceback.format_tb(exc.__traceback__)), dst)
raise AssertionError(
def dump_to_file(*output: str) -> str:
"""Dump `output` to a temporary file. Return path to the file."""
- import tempfile
-
with tempfile.NamedTemporaryFile(
mode="w", prefix="blk_", suffix=".log", delete=False, encoding="utf8"
) as f:
if "\n" in leaf.value:
return # Multiline strings, we can't continue.
- comment: Optional[Leaf]
for comment in line.comments_after(leaf):
length += len(comment.value)