tests/test_black.py

   1 #!/usr/bin/env python3
   2 from functools import partial
   3 from io import StringIO
   4 import os
   5 from pathlib import Path
   6 import sys
   7 from typing import Any, List, Tuple
   8 import unittest
   9 from unittest.mock import patch
  10
  11 from click import unstyle
  12
  13 import black
  14
  15 ll = 88
  16 ff = partial(black.format_file_in_place, line_length=ll, fast=True)
  17 fs = partial(black.format_str, line_length=ll)
  18 THIS_FILE = Path(__file__)
  19 THIS_DIR = THIS_FILE.parent
  20
  21
  22 def dump_to_stderr(*output: str) -> str:
  23     return '\n' + '\n'.join(output) + '\n'
  24
  25
  26 def read_data(name: str) -> Tuple[str, str]:
  27     """read_data('test_name') -> 'input', 'output'"""
  28     if not name.endswith('.py'):
  29         name += '.py'
  30     _input: List[str] = []
  31     _output: List[str] = []
  32     with open(THIS_DIR / name, 'r', encoding='utf8') as test:
  33         lines = test.readlines()
  34     result = _input
  35     for line in lines:
  36         if line.rstrip() == '# output':
  37             result = _output
  38             continue
  39
  40         result.append(line)
  41     if _input and not _output:
  42         # If there's no output marker, treat the entire file as already pre-formatted.
  43         _output = _input[:]
  44     return ''.join(_input).strip() + '\n', ''.join(_output).strip() + '\n'
  45
  46
  47 class BlackTestCase(unittest.TestCase):
  48     maxDiff = None
  49
  50     def assertFormatEqual(self, expected: str, actual: str) -> None:
  51         if actual != expected and not os.environ.get('SKIP_AST_PRINT'):
  52             bdv: black.DebugVisitor[Any]
  53             black.out('Expected tree:', fg='green')
  54             try:
  55                 exp_node = black.lib2to3_parse(expected)
  56                 bdv = black.DebugVisitor()
  57                 list(bdv.visit(exp_node))
  58             except Exception as ve:
  59                 black.err(str(ve))
  60             black.out('Actual tree:', fg='red')
  61             try:
  62                 exp_node = black.lib2to3_parse(actual)
  63                 bdv = black.DebugVisitor()
  64                 list(bdv.visit(exp_node))
  65             except Exception as ve:
  66                 black.err(str(ve))
  67         self.assertEqual(expected, actual)
  68
  69     @patch("black.dump_to_file", dump_to_stderr)
  70     def test_self(self) -> None:
  71         source, expected = read_data('test_black')
  72         actual = fs(source)
  73         self.assertFormatEqual(expected, actual)
  74         black.assert_equivalent(source, actual)
  75         black.assert_stable(source, actual, line_length=ll)
  76         self.assertFalse(ff(THIS_FILE))
  77
  78     @patch("black.dump_to_file", dump_to_stderr)
  79     def test_black(self) -> None:
  80         source, expected = read_data('../black')
  81         actual = fs(source)
  82         self.assertFormatEqual(expected, actual)
  83         black.assert_equivalent(source, actual)
  84         black.assert_stable(source, actual, line_length=ll)
  85         self.assertFalse(ff(THIS_DIR / '..' / 'black.py'))
  86
  87     def test_piping(self) -> None:
  88         source, expected = read_data('../black')
  89         hold_stdin, hold_stdout = sys.stdin, sys.stdout
  90         try:
  91             sys.stdin, sys.stdout = StringIO(source), StringIO()
  92             sys.stdin.name = '<stdin>'
  93             black.format_stdin_to_stdout(line_length=ll, fast=True, write_back=True)
  94             sys.stdout.seek(0)
  95             actual = sys.stdout.read()
  96         finally:
  97             sys.stdin, sys.stdout = hold_stdin, hold_stdout
  98         self.assertFormatEqual(expected, actual)
  99         black.assert_equivalent(source, actual)
 100         black.assert_stable(source, actual, line_length=ll)
 101
 102     @patch("black.dump_to_file", dump_to_stderr)
 103     def test_setup(self) -> None:
 104         source, expected = read_data('../setup')
 105         actual = fs(source)
 106         self.assertFormatEqual(expected, actual)
 107         black.assert_equivalent(source, actual)
 108         black.assert_stable(source, actual, line_length=ll)
 109         self.assertFalse(ff(THIS_DIR / '..' / 'setup.py'))
 110
 111     @patch("black.dump_to_file", dump_to_stderr)
 112     def test_function(self) -> None:
 113         source, expected = read_data('function')
 114         actual = fs(source)
 115         self.assertFormatEqual(expected, actual)
 116         black.assert_equivalent(source, actual)
 117         black.assert_stable(source, actual, line_length=ll)
 118
 119     @patch("black.dump_to_file", dump_to_stderr)
 120     def test_expression(self) -> None:
 121         source, expected = read_data('expression')
 122         actual = fs(source)
 123         self.assertFormatEqual(expected, actual)
 124         black.assert_equivalent(source, actual)
 125         black.assert_stable(source, actual, line_length=ll)
 126
 127     @patch("black.dump_to_file", dump_to_stderr)
 128     def test_fstring(self) -> None:
 129         source, expected = read_data('fstring')
 130         actual = fs(source)
 131         self.assertFormatEqual(expected, actual)
 132         black.assert_equivalent(source, actual)
 133         black.assert_stable(source, actual, line_length=ll)
 134
 135     @patch("black.dump_to_file", dump_to_stderr)
 136     def test_comments(self) -> None:
 137         source, expected = read_data('comments')
 138         actual = fs(source)
 139         self.assertFormatEqual(expected, actual)
 140         black.assert_equivalent(source, actual)
 141         black.assert_stable(source, actual, line_length=ll)
 142
 143     @patch("black.dump_to_file", dump_to_stderr)
 144     def test_comments2(self) -> None:
 145         source, expected = read_data('comments2')
 146         actual = fs(source)
 147         self.assertFormatEqual(expected, actual)
 148         black.assert_equivalent(source, actual)
 149         black.assert_stable(source, actual, line_length=ll)
 150
 151     @patch("black.dump_to_file", dump_to_stderr)
 152     def test_cantfit(self) -> None:
 153         source, expected = read_data('cantfit')
 154         actual = fs(source)
 155         self.assertFormatEqual(expected, actual)
 156         black.assert_equivalent(source, actual)
 157         black.assert_stable(source, actual, line_length=ll)
 158
 159     @patch("black.dump_to_file", dump_to_stderr)
 160     def test_import_spacing(self) -> None:
 161         source, expected = read_data('import_spacing')
 162         actual = fs(source)
 163         self.assertFormatEqual(expected, actual)
 164         black.assert_equivalent(source, actual)
 165         black.assert_stable(source, actual, line_length=ll)
 166
 167     @patch("black.dump_to_file", dump_to_stderr)
 168     def test_composition(self) -> None:
 169         source, expected = read_data('composition')
 170         actual = fs(source)
 171         self.assertFormatEqual(expected, actual)
 172         black.assert_equivalent(source, actual)
 173         black.assert_stable(source, actual, line_length=ll)
 174
 175     @patch("black.dump_to_file", dump_to_stderr)
 176     def test_empty_lines(self) -> None:
 177         source, expected = read_data('empty_lines')
 178         actual = fs(source)
 179         self.assertFormatEqual(expected, actual)
 180         black.assert_equivalent(source, actual)
 181         black.assert_stable(source, actual, line_length=ll)
 182
 183     def test_report(self) -> None:
 184         report = black.Report()
 185         out_lines = []
 186         err_lines = []
 187
 188         def out(msg: str, **kwargs: Any) -> None:
 189             out_lines.append(msg)
 190
 191         def err(msg: str, **kwargs: Any) -> None:
 192             err_lines.append(msg)
 193
 194         with patch("black.out", out), patch("black.err", err):
 195             report.done(Path('f1'), changed=False)
 196             self.assertEqual(len(out_lines), 1)
 197             self.assertEqual(len(err_lines), 0)
 198             self.assertEqual(out_lines[-1], 'f1 already well formatted, good job.')
 199             self.assertEqual(unstyle(str(report)), '1 file left unchanged.')
 200             self.assertEqual(report.return_code, 0)
 201             report.done(Path('f2'), changed=True)
 202             self.assertEqual(len(out_lines), 2)
 203             self.assertEqual(len(err_lines), 0)
 204             self.assertEqual(out_lines[-1], 'reformatted f2')
 205             self.assertEqual(
 206                 unstyle(str(report)), '1 file reformatted, 1 file left unchanged.'
 207             )
 208             self.assertEqual(report.return_code, 0)
 209             report.check = True
 210             self.assertEqual(report.return_code, 1)
 211             report.check = False
 212             report.failed(Path('e1'), 'boom')
 213             self.assertEqual(len(out_lines), 2)
 214             self.assertEqual(len(err_lines), 1)
 215             self.assertEqual(err_lines[-1], 'error: cannot format e1: boom')
 216             self.assertEqual(
 217                 unstyle(str(report)),
 218                 '1 file reformatted, 1 file left unchanged, '
 219                 '1 file failed to reformat.',
 220             )
 221             self.assertEqual(report.return_code, 123)
 222             report.done(Path('f3'), changed=True)
 223             self.assertEqual(len(out_lines), 3)
 224             self.assertEqual(len(err_lines), 1)
 225             self.assertEqual(out_lines[-1], 'reformatted f3')
 226             self.assertEqual(
 227                 unstyle(str(report)),
 228                 '2 files reformatted, 1 file left unchanged, '
 229                 '1 file failed to reformat.',
 230             )
 231             self.assertEqual(report.return_code, 123)
 232             report.failed(Path('e2'), 'boom')
 233             self.assertEqual(len(out_lines), 3)
 234             self.assertEqual(len(err_lines), 2)
 235             self.assertEqual(err_lines[-1], 'error: cannot format e2: boom')
 236             self.assertEqual(
 237                 unstyle(str(report)),
 238                 '2 files reformatted, 1 file left unchanged, '
 239                 '2 files failed to reformat.',
 240             )
 241             self.assertEqual(report.return_code, 123)
 242             report.done(Path('f4'), changed=False)
 243             self.assertEqual(len(out_lines), 4)
 244             self.assertEqual(len(err_lines), 2)
 245             self.assertEqual(out_lines[-1], 'f4 already well formatted, good job.')
 246             self.assertEqual(
 247                 unstyle(str(report)),
 248                 '2 files reformatted, 2 files left unchanged, '
 249                 '2 files failed to reformat.',
 250             )
 251             self.assertEqual(report.return_code, 123)
 252             report.check = True
 253             self.assertEqual(
 254                 unstyle(str(report)),
 255                 '2 files would be reformatted, 2 files would be left unchanged, '
 256                 '2 files would fail to reformat.',
 257             )
 258
 259     def test_is_python36(self) -> None:
 260         node = black.lib2to3_parse("def f(*, arg): ...\n")
 261         self.assertFalse(black.is_python36(node))
 262         node = black.lib2to3_parse("def f(*, arg,): ...\n")
 263         self.assertTrue(black.is_python36(node))
 264         node = black.lib2to3_parse("def f(*, arg): f'string'\n")
 265         self.assertTrue(black.is_python36(node))
 266         source, expected = read_data('function')
 267         node = black.lib2to3_parse(source)
 268         self.assertTrue(black.is_python36(node))
 269         node = black.lib2to3_parse(expected)
 270         self.assertTrue(black.is_python36(node))
 271         source, expected = read_data('expression')
 272         node = black.lib2to3_parse(source)
 273         self.assertFalse(black.is_python36(node))
 274         node = black.lib2to3_parse(expected)
 275         self.assertFalse(black.is_python36(node))
 276
 277
 278 if __name__ == '__main__':
 279     unittest.main()