From 10d8976a79f5a7f7e5e36369a81d9e5c983332d1 Mon Sep 17 00:00:00 2001 From: treuherz <1574403+treuherz@users.noreply.github.com> Date: Mon, 19 Mar 2018 18:07:10 +0000 Subject: [PATCH] Add piping from stdin to stdout with a - (#25) Being able to format code by piping it through the formatter makes it much easier to integrate with tools like google/vim-codefmt or Chiel92/vim-autoformat. --- black.py | 51 ++++++++++++++++++++++++++++++++------------- tests/test_black.py | 28 ++++++++++++++++++------- 2 files changed, 58 insertions(+), 21 deletions(-) diff --git a/black.py b/black.py index b2b2db7..6bfef50 100644 --- a/black.py +++ b/black.py @@ -74,7 +74,9 @@ class CannotSplit(Exception): @click.argument( 'src', nargs=-1, - type=click.Path(exists=True, file_okay=True, dir_okay=True, readable=True), + type=click.Path( + exists=True, file_okay=True, dir_okay=True, readable=True, allow_dash=True + ), ) @click.pass_context def main( @@ -89,6 +91,8 @@ def main( elif p.is_file(): # if a file was explicitly given, we don't care about its extension sources.append(p) + elif s == '-': + sources.append(Path('-')) else: err(f'invalid path: {s}') if len(sources) == 0: @@ -97,9 +101,12 @@ def main( p = sources[0] report = Report() try: - changed = format_file_in_place( - p, line_length=line_length, fast=fast, write_back=not check - ) + if not p.is_file() and str(p) == '-': + changed = format_stdin_to_stdout(line_length=line_length, fast=fast) + else: + changed = format_file_in_place( + p, line_length=line_length, fast=fast, write_back=not check + ) report.done(p, changed) except Exception as exc: report.failed(p, str(exc)) @@ -156,34 +163,50 @@ def format_file_in_place( src: Path, line_length: int, fast: bool, write_back: bool = False ) -> bool: """Format the file and rewrite if changed. Return True if changed.""" + with tokenize.open(src) as src_buffer: + src_contents = src_buffer.read() try: - contents, encoding = format_file(src, line_length=line_length, fast=fast) + contents = format_file_contents( + src_contents, line_length=line_length, fast=fast + ) except NothingChanged: return False if write_back: - with open(src, "w", encoding=encoding) as f: + with open(src, "w", encoding=src_buffer.encoding) as f: f.write(contents) return True -def format_file( - src: Path, line_length: int, fast: bool -) -> Tuple[FileContent, Encoding]: +def format_stdin_to_stdout(line_length: int, fast: bool) -> bool: + """Format file on stdin and pipe output to stdout. Return True if changed.""" + contents = sys.stdin.read() + try: + contents = format_file_contents(contents, line_length=line_length, fast=fast) + return True + + except NothingChanged: + return False + + finally: + sys.stdout.write(contents) + + +def format_file_contents( + src_contents: str, line_length: int, fast: bool +) -> FileContent: """Reformats a file and returns its contents and encoding.""" - with tokenize.open(src) as src_buffer: - src_contents = src_buffer.read() if src_contents.strip() == '': - raise NothingChanged(src) + raise NothingChanged dst_contents = format_str(src_contents, line_length=line_length) if src_contents == dst_contents: - raise NothingChanged(src) + raise NothingChanged if not fast: assert_equivalent(src_contents, dst_contents) assert_stable(src_contents, dst_contents, line_length=line_length) - return dst_contents, src_buffer.encoding + return dst_contents def format_str(src_contents: str, line_length: int) -> FileContent: diff --git a/tests/test_black.py b/tests/test_black.py index c11fca0..225ece6 100644 --- a/tests/test_black.py +++ b/tests/test_black.py @@ -1,6 +1,8 @@ #!/usr/bin/env python3 from functools import partial +from io import StringIO from pathlib import Path +import sys from typing import Any, List, Tuple import unittest from unittest.mock import patch @@ -10,7 +12,7 @@ from click import unstyle import black ll = 88 -ff = partial(black.format_file, line_length=ll, fast=True) +ff = partial(black.format_file_in_place, line_length=ll, fast=True) fs = partial(black.format_str, line_length=ll) THIS_FILE = Path(__file__) THIS_DIR = THIS_FILE.parent @@ -70,8 +72,7 @@ class BlackTestCase(unittest.TestCase): self.assertFormatEqual(expected, actual) black.assert_equivalent(source, actual) black.assert_stable(source, actual, line_length=ll) - with self.assertRaises(black.NothingChanged): - ff(THIS_FILE) + self.assertFalse(ff(THIS_FILE)) @patch("black.dump_to_file", dump_to_stderr) def test_black(self) -> None: @@ -80,8 +81,22 @@ class BlackTestCase(unittest.TestCase): self.assertFormatEqual(expected, actual) black.assert_equivalent(source, actual) black.assert_stable(source, actual, line_length=ll) - with self.assertRaises(black.NothingChanged): - ff(THIS_FILE) + self.assertFalse(ff(THIS_DIR / '..' / 'black.py')) + + def test_piping(self) -> None: + source, expected = read_data('../black') + hold_stdin, hold_stdout = sys.stdin, sys.stdout + try: + sys.stdin, sys.stdout = StringIO(source), StringIO() + sys.stdin.name = '' + black.format_stdin_to_stdout(line_length=ll, fast=True) + sys.stdout.seek(0) + actual = sys.stdout.read() + finally: + sys.stdin, sys.stdout = hold_stdin, hold_stdout + self.assertFormatEqual(expected, actual) + black.assert_equivalent(source, actual) + black.assert_stable(source, actual, line_length=ll) @patch("black.dump_to_file", dump_to_stderr) def test_setup(self) -> None: @@ -90,8 +105,7 @@ class BlackTestCase(unittest.TestCase): self.assertFormatEqual(expected, actual) black.assert_equivalent(source, actual) black.assert_stable(source, actual, line_length=ll) - with self.assertRaises(black.NothingChanged): - ff(THIS_FILE) + self.assertFalse(ff(THIS_DIR / '..' / 'setup.py')) @patch("black.dump_to_file", dump_to_stderr) def test_function(self) -> None: -- 2.39.5