import asyncio
from asyncio.base_events import BaseEventLoop
from concurrent.futures import Executor, ProcessPoolExecutor
+from enum import Enum
from functools import partial, wraps
import keyword
import logging
+from multiprocessing import Manager
import os
from pathlib import Path
import tokenize
import signal
import sys
from typing import (
+ Any,
Callable,
Dict,
Generic,
"""Found a comment like `# fmt: off` in the file."""
+class WriteBack(Enum):
+ NO = 0
+ YES = 1
+ DIFF = 2
+
+
@click.command()
@click.option(
"-l",
"--check",
is_flag=True,
help=(
- "Don't write back the files, just return the status. Return code 0 "
+ "Don't write the files back, just return the status. Return code 0 "
"means nothing would change. Return code 1 means some files would be "
"reformatted. Return code 123 means there was an internal error."
),
)
+@click.option(
+ "--diff",
+ is_flag=True,
+ help="Don't write the files back, just output a diff for each file on stdout.",
+)
@click.option(
"--fast/--safe",
is_flag=True,
)
@click.pass_context
def main(
- ctx: click.Context, line_length: int, check: bool, fast: bool, src: List[str]
+ ctx: click.Context,
+ line_length: int,
+ check: bool,
+ diff: bool,
+ fast: bool,
+ src: List[str],
) -> None:
"""The uncompromising code formatter."""
sources: List[Path] = []
sources.append(Path("-"))
else:
err(f"invalid path: {s}")
+ if check and diff:
+ exc = click.ClickException("Options --check and --diff are mutually exclusive")
+ exc.exit_code = 2
+ raise exc
+
+ if check:
+ write_back = WriteBack.NO
+ elif diff:
+ write_back = WriteBack.DIFF
+ else:
+ write_back = WriteBack.YES
if len(sources) == 0:
ctx.exit(0)
elif len(sources) == 1:
try:
if not p.is_file() and str(p) == "-":
changed = format_stdin_to_stdout(
- line_length=line_length, fast=fast, write_back=not check
+ line_length=line_length, fast=fast, write_back=write_back
)
else:
changed = format_file_in_place(
- p, line_length=line_length, fast=fast, write_back=not check
+ p, line_length=line_length, fast=fast, write_back=write_back
)
report.done(p, changed)
except Exception as exc:
try:
return_code = loop.run_until_complete(
schedule_formatting(
- sources, line_length, not check, fast, loop, executor
+ sources, line_length, write_back, fast, loop, executor
)
)
finally:
async def schedule_formatting(
sources: List[Path],
line_length: int,
- write_back: bool,
+ write_back: WriteBack,
fast: bool,
loop: BaseEventLoop,
executor: Executor,
`line_length`, `write_back`, and `fast` options are passed to
:func:`format_file_in_place`.
"""
+ lock = None
+ if write_back == WriteBack.DIFF:
+ # For diff output, we need locks to ensure we don't interleave output
+ # from different processes.
+ manager = Manager()
+ lock = manager.Lock()
tasks = {
src: loop.run_in_executor(
- executor, format_file_in_place, src, line_length, fast, write_back
+ executor, format_file_in_place, src, line_length, fast, write_back, lock
)
for src in sources
}
def format_file_in_place(
- src: Path, line_length: int, fast: bool, write_back: bool = False
+ src: Path,
+ line_length: int,
+ fast: bool,
+ write_back: WriteBack = WriteBack.NO,
+ lock: Any = None, # multiprocessing.Manager().Lock() is some crazy proxy
) -> bool:
"""Format file under `src` path. Return True if changed.
with tokenize.open(src) as src_buffer:
src_contents = src_buffer.read()
try:
- contents = format_file_contents(
+ dst_contents = format_file_contents(
src_contents, line_length=line_length, fast=fast
)
except NothingChanged:
return False
- if write_back:
+ if write_back == write_back.YES:
with open(src, "w", encoding=src_buffer.encoding) as f:
- f.write(contents)
+ f.write(dst_contents)
+ elif write_back == write_back.DIFF:
+ src_name = f"{src.name} (original)"
+ dst_name = f"{src.name} (formatted)"
+ diff_contents = diff(src_contents, dst_contents, src_name, dst_name)
+ if lock:
+ lock.acquire()
+ try:
+ sys.stdout.write(diff_contents)
+ finally:
+ if lock:
+ lock.release()
return True
def format_stdin_to_stdout(
- line_length: int, fast: bool, write_back: bool = False
+ line_length: int, fast: bool, write_back: WriteBack = WriteBack.NO
) -> 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`.
"""
- contents = sys.stdin.read()
+ src = sys.stdin.read()
try:
- contents = format_file_contents(contents, line_length=line_length, fast=fast)
+ dst = format_file_contents(src, line_length=line_length, fast=fast)
return True
except NothingChanged:
+ dst = src
return False
finally:
- if write_back:
- sys.stdout.write(contents)
+ if write_back == WriteBack.YES:
+ sys.stdout.write(dst)
+ elif write_back == WriteBack.DIFF:
+ src_name = "<stdin> (original)"
+ dst_name = "<stdin> (formatted)"
+ sys.stdout.write(diff(src, dst, src_name, dst_name))
def format_file_contents(
token.DOUBLESTAR,
token.DOUBLESLASH,
}
+VARARGS = {token.STAR, token.DOUBLESTAR}
COMPREHENSION_PRIORITY = 20
COMMA_PRIORITY = 10
LOGIC_PRIORITY = 5
leaf.opening_bracket = opening_bracket
leaf.bracket_depth = self.depth
if self.depth == 0:
- delim = is_delimiter(leaf)
- if delim:
- self.delimiters[id(leaf)] = delim
- elif self.previous is not None:
- if leaf.type == token.STRING and self.previous.type == token.STRING:
- self.delimiters[id(self.previous)] = STRING_PRIORITY
- elif (
- leaf.type == token.NAME
- and leaf.value == "for"
- and leaf.parent
- and leaf.parent.type in {syms.comp_for, syms.old_comp_for}
- ):
- self.delimiters[id(self.previous)] = COMPREHENSION_PRIORITY
- elif (
- leaf.type == token.NAME
- and leaf.value == "if"
- and leaf.parent
- and leaf.parent.type in {syms.comp_if, syms.old_comp_if}
- ):
- self.delimiters[id(self.previous)] = COMPREHENSION_PRIORITY
- elif (
- leaf.type == token.NAME
- and leaf.value in LOGIC_OPERATORS
- and leaf.parent
- ):
- self.delimiters[id(self.previous)] = LOGIC_PRIORITY
+ after_delim = is_split_after_delimiter(leaf, self.previous)
+ before_delim = is_split_before_delimiter(leaf, self.previous)
+ if after_delim > before_delim:
+ self.delimiters[id(leaf)] = after_delim
+ elif before_delim > after_delim and self.previous is not None:
+ self.delimiters[id(self.previous)] = before_delim
if leaf.type in OPENING_BRACKETS:
self.bracket_match[self.depth, BRACKET[leaf.type]] = leaf
self.depth += 1
return None
-def is_delimiter(leaf: Leaf) -> int:
- """Return the priority of the `leaf` delimiter. Return 0 if not delimiter.
+def is_split_after_delimiter(leaf: Leaf, previous: Leaf = None) -> int:
+ """Return the priority of the `leaf` delimiter, given a line break after it.
+
+ The delimiter priorities returned here are from those delimiters that would
+ cause a line break after themselves.
Higher numbers are higher priority.
"""
if leaf.type == token.COMMA:
return COMMA_PRIORITY
- if leaf.type in COMPARATORS:
- return COMPARATOR_PRIORITY
+ if (
+ leaf.type in VARARGS
+ and leaf.parent
+ and leaf.parent.type in {syms.argument, syms.typedargslist}
+ ):
+ return MATH_PRIORITY
+ return 0
+
+
+def is_split_before_delimiter(leaf: Leaf, previous: Leaf = None) -> int:
+ """Return the priority of the `leaf` delimiter, given a line before after it.
+
+ The delimiter priorities returned here are from those delimiters that would
+ cause a line break before themselves.
+
+ Higher numbers are higher priority.
+ """
if (
leaf.type in MATH_OPERATORS
and leaf.parent
):
return MATH_PRIORITY
+ if leaf.type in COMPARATORS:
+ return COMPARATOR_PRIORITY
+
+ if (
+ leaf.type == token.STRING
+ and previous is not None
+ and previous.type == token.STRING
+ ):
+ return STRING_PRIORITY
+
+ if (
+ leaf.type == token.NAME
+ and 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"
+ 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:
+ return LOGIC_PRIORITY
+
return 0
+def is_delimiter(leaf: Leaf, previous: Leaf = None) -> int:
+ """Return the priority of the `leaf` delimiter. Return 0 if not delimiter.
+
+ Higher numbers are higher priority.
+ """
+ return max(
+ is_split_before_delimiter(leaf, previous),
+ is_split_after_delimiter(leaf, previous),
+ )
+
+
def generate_comments(leaf: Leaf) -> Iterator[Leaf]:
"""Clean the prefix of the `leaf` and generate comments from it, if any.
def normalize_string_quotes(leaf: Leaf) -> None:
+ """Prefer double quotes but only if it doesn't cause more escaping.
+
+ Adds or removes backslashes as appropriate. Doesn't parse and fix
+ strings nested in f-strings (yet).
+
+ Note: Mutates its argument.
+ """
value = leaf.value.lstrip("furbFURB")
if value[:3] == '"""':
return
) as f:
for lines in output:
f.write(lines)
- f.write("\n")
+ if lines and lines[-1] != "\n":
+ f.write("\n")
return f.name