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 EMPTY_LINE = "# EMPTY LINE WITH WHITESPACE" + " (this comment will be removed)"
  21
  22
  23 def dump_to_stderr(*output: str) -> str:
  24     return "\n" + "\n".join(output) + "\n"
  25
  26
  27 def read_data(name: str) -> Tuple[str, str]:
  28     """read_data('test_name') -> 'input', 'output'"""
  29     if not name.endswith((".py", ".out", ".diff")):
  30         name += ".py"
  31     _input: List[str] = []
  32     _output: List[str] = []
  33     with open(THIS_DIR / name, "r", encoding="utf8") as test:
  34         lines = test.readlines()
  35     result = _input
  36     for line in lines:
  37         line = line.replace(EMPTY_LINE, "")
  38         if line.rstrip() == "# output":
  39             result = _output
  40             continue
  41
  42         result.append(line)
  43     if _input and not _output:
  44         # If there's no output marker, treat the entire file as already pre-formatted.
  45         _output = _input[:]
  46     return "".join(_input).strip() + "\n", "".join(_output).strip() + "\n"
  47
  48
  49 class BlackTestCase(unittest.TestCase):
  50     maxDiff = None
  51
  52     def assertFormatEqual(self, expected: str, actual: str) -> None:
  53         if actual != expected and not os.environ.get("SKIP_AST_PRINT"):
  54             bdv: black.DebugVisitor[Any]
  55             black.out("Expected tree:", fg="green")
  56             try:
  57                 exp_node = black.lib2to3_parse(expected)
  58                 bdv = black.DebugVisitor()
  59                 list(bdv.visit(exp_node))
  60             except Exception as ve:
  61                 black.err(str(ve))
  62             black.out("Actual tree:", fg="red")
  63             try:
  64                 exp_node = black.lib2to3_parse(actual)
  65                 bdv = black.DebugVisitor()
  66                 list(bdv.visit(exp_node))
  67             except Exception as ve:
  68                 black.err(str(ve))
  69         self.assertEqual(expected, actual)
  70
  71     @patch("black.dump_to_file", dump_to_stderr)
  72     def test_self(self) -> None:
  73         source, expected = read_data("test_black")
  74         actual = fs(source)
  75         self.assertFormatEqual(expected, actual)
  76         black.assert_equivalent(source, actual)
  77         black.assert_stable(source, actual, line_length=ll)
  78         self.assertFalse(ff(THIS_FILE))
  79
  80     @patch("black.dump_to_file", dump_to_stderr)
  81     def test_black(self) -> None:
  82         source, expected = read_data("../black")
  83         actual = fs(source)
  84         self.assertFormatEqual(expected, actual)
  85         black.assert_equivalent(source, actual)
  86         black.assert_stable(source, actual, line_length=ll)
  87         self.assertFalse(ff(THIS_DIR / ".." / "black.py"))
  88
  89     def test_piping(self) -> None:
  90         source, expected = read_data("../black")
  91         hold_stdin, hold_stdout = sys.stdin, sys.stdout
  92         try:
  93             sys.stdin, sys.stdout = StringIO(source), StringIO()
  94             sys.stdin.name = "<stdin>"
  95             black.format_stdin_to_stdout(
  96                 line_length=ll, fast=True, write_back=black.WriteBack.YES
  97             )
  98             sys.stdout.seek(0)
  99             actual = sys.stdout.read()
 100         finally:
 101             sys.stdin, sys.stdout = hold_stdin, hold_stdout
 102         self.assertFormatEqual(expected, actual)
 103         black.assert_equivalent(source, actual)
 104         black.assert_stable(source, actual, line_length=ll)
 105
 106     def test_piping_diff(self) -> None:
 107         source, _ = read_data("expression.py")
 108         expected, _ = read_data("expression.diff")
 109         hold_stdin, hold_stdout = sys.stdin, sys.stdout
 110         try:
 111             sys.stdin, sys.stdout = StringIO(source), StringIO()
 112             sys.stdin.name = "<stdin>"
 113             black.format_stdin_to_stdout(
 114                 line_length=ll, fast=True, write_back=black.WriteBack.DIFF
 115             )
 116             sys.stdout.seek(0)
 117             actual = sys.stdout.read()
 118         finally:
 119             sys.stdin, sys.stdout = hold_stdin, hold_stdout
 120         actual = actual.rstrip() + "\n"  # the diff output has a trailing space
 121         self.assertEqual(expected, actual)
 122
 123     @patch("black.dump_to_file", dump_to_stderr)
 124     def test_setup(self) -> None:
 125         source, expected = read_data("../setup")
 126         actual = fs(source)
 127         self.assertFormatEqual(expected, actual)
 128         black.assert_equivalent(source, actual)
 129         black.assert_stable(source, actual, line_length=ll)
 130         self.assertFalse(ff(THIS_DIR / ".." / "setup.py"))
 131
 132     @patch("black.dump_to_file", dump_to_stderr)
 133     def test_function(self) -> None:
 134         source, expected = read_data("function")
 135         actual = fs(source)
 136         self.assertFormatEqual(expected, actual)
 137         black.assert_equivalent(source, actual)
 138         black.assert_stable(source, actual, line_length=ll)
 139
 140     @patch("black.dump_to_file", dump_to_stderr)
 141     def test_expression(self) -> None:
 142         source, expected = read_data("expression")
 143         actual = fs(source)
 144         self.assertFormatEqual(expected, actual)
 145         black.assert_equivalent(source, actual)
 146         black.assert_stable(source, actual, line_length=ll)
 147
 148     def test_expression_ff(self) -> None:
 149         source, expected = read_data("expression")
 150         tmp_file = Path(black.dump_to_file(source))
 151         try:
 152             self.assertTrue(ff(tmp_file, write_back=black.WriteBack.YES))
 153             with open(tmp_file) as f:
 154                 actual = f.read()
 155         finally:
 156             os.unlink(tmp_file)
 157         self.assertFormatEqual(expected, actual)
 158         with patch("black.dump_to_file", dump_to_stderr):
 159             black.assert_equivalent(source, actual)
 160             black.assert_stable(source, actual, line_length=ll)
 161
 162     def test_expression_diff(self) -> None:
 163         source, _ = read_data("expression.py")
 164         expected, _ = read_data("expression.diff")
 165         tmp_file = Path(black.dump_to_file(source))
 166         hold_stdout = sys.stdout
 167         try:
 168             sys.stdout = StringIO()
 169             self.assertTrue(ff(tmp_file, write_back=black.WriteBack.DIFF))
 170             sys.stdout.seek(0)
 171             actual = sys.stdout.read()
 172             actual = actual.replace(tmp_file.name, "<stdin>")
 173         finally:
 174             sys.stdout = hold_stdout
 175             os.unlink(tmp_file)
 176         actual = actual.rstrip() + "\n"  # the diff output has a trailing space
 177         self.assertEqual(expected, actual)
 178
 179     @patch("black.dump_to_file", dump_to_stderr)
 180     def test_fstring(self) -> None:
 181         source, expected = read_data("fstring")
 182         actual = fs(source)
 183         self.assertFormatEqual(expected, actual)
 184         black.assert_equivalent(source, actual)
 185         black.assert_stable(source, actual, line_length=ll)
 186
 187     @patch("black.dump_to_file", dump_to_stderr)
 188     def test_string_quotes(self) -> None:
 189         source, expected = read_data("string_quotes")
 190         actual = fs(source)
 191         self.assertFormatEqual(expected, actual)
 192         black.assert_equivalent(source, actual)
 193         black.assert_stable(source, actual, line_length=ll)
 194
 195     @patch("black.dump_to_file", dump_to_stderr)
 196     def test_comments(self) -> None:
 197         source, expected = read_data("comments")
 198         actual = fs(source)
 199         self.assertFormatEqual(expected, actual)
 200         black.assert_equivalent(source, actual)
 201         black.assert_stable(source, actual, line_length=ll)
 202
 203     @patch("black.dump_to_file", dump_to_stderr)
 204     def test_comments2(self) -> None:
 205         source, expected = read_data("comments2")
 206         actual = fs(source)
 207         self.assertFormatEqual(expected, actual)
 208         black.assert_equivalent(source, actual)
 209         black.assert_stable(source, actual, line_length=ll)
 210
 211     @patch("black.dump_to_file", dump_to_stderr)
 212     def test_comments3(self) -> None:
 213         source, expected = read_data("comments3")
 214         actual = fs(source)
 215         self.assertFormatEqual(expected, actual)
 216         black.assert_equivalent(source, actual)
 217         black.assert_stable(source, actual, line_length=ll)
 218
 219     @patch("black.dump_to_file", dump_to_stderr)
 220     def test_comments4(self) -> None:
 221         source, expected = read_data("comments4")
 222         actual = fs(source)
 223         self.assertFormatEqual(expected, actual)
 224         black.assert_equivalent(source, actual)
 225         black.assert_stable(source, actual, line_length=ll)
 226
 227     @patch("black.dump_to_file", dump_to_stderr)
 228     def test_cantfit(self) -> None:
 229         source, expected = read_data("cantfit")
 230         actual = fs(source)
 231         self.assertFormatEqual(expected, actual)
 232         black.assert_equivalent(source, actual)
 233         black.assert_stable(source, actual, line_length=ll)
 234
 235     @patch("black.dump_to_file", dump_to_stderr)
 236     def test_import_spacing(self) -> None:
 237         source, expected = read_data("import_spacing")
 238         actual = fs(source)
 239         self.assertFormatEqual(expected, actual)
 240         black.assert_equivalent(source, actual)
 241         black.assert_stable(source, actual, line_length=ll)
 242
 243     @patch("black.dump_to_file", dump_to_stderr)
 244     def test_composition(self) -> None:
 245         source, expected = read_data("composition")
 246         actual = fs(source)
 247         self.assertFormatEqual(expected, actual)
 248         black.assert_equivalent(source, actual)
 249         black.assert_stable(source, actual, line_length=ll)
 250
 251     @patch("black.dump_to_file", dump_to_stderr)
 252     def test_empty_lines(self) -> None:
 253         source, expected = read_data("empty_lines")
 254         actual = fs(source)
 255         self.assertFormatEqual(expected, actual)
 256         black.assert_equivalent(source, actual)
 257         black.assert_stable(source, actual, line_length=ll)
 258
 259     @patch("black.dump_to_file", dump_to_stderr)
 260     def test_python2(self) -> None:
 261         source, expected = read_data("python2")
 262         actual = fs(source)
 263         self.assertFormatEqual(expected, actual)
 264         # black.assert_equivalent(source, actual)
 265         black.assert_stable(source, actual, line_length=ll)
 266
 267     @patch("black.dump_to_file", dump_to_stderr)
 268     def test_fmtonoff(self) -> None:
 269         source, expected = read_data("fmtonoff")
 270         actual = fs(source)
 271         self.assertFormatEqual(expected, actual)
 272         black.assert_equivalent(source, actual)
 273         black.assert_stable(source, actual, line_length=ll)
 274
 275     def test_report(self) -> None:
 276         report = black.Report()
 277         out_lines = []
 278         err_lines = []
 279
 280         def out(msg: str, **kwargs: Any) -> None:
 281             out_lines.append(msg)
 282
 283         def err(msg: str, **kwargs: Any) -> None:
 284             err_lines.append(msg)
 285
 286         with patch("black.out", out), patch("black.err", err):
 287             report.done(Path("f1"), changed=False)
 288             self.assertEqual(len(out_lines), 1)
 289             self.assertEqual(len(err_lines), 0)
 290             self.assertEqual(out_lines[-1], "f1 already well formatted, good job.")
 291             self.assertEqual(unstyle(str(report)), "1 file left unchanged.")
 292             self.assertEqual(report.return_code, 0)
 293             report.done(Path("f2"), changed=True)
 294             self.assertEqual(len(out_lines), 2)
 295             self.assertEqual(len(err_lines), 0)
 296             self.assertEqual(out_lines[-1], "reformatted f2")
 297             self.assertEqual(
 298                 unstyle(str(report)), "1 file reformatted, 1 file left unchanged."
 299             )
 300             self.assertEqual(report.return_code, 0)
 301             report.check = True
 302             self.assertEqual(report.return_code, 1)
 303             report.check = False
 304             report.failed(Path("e1"), "boom")
 305             self.assertEqual(len(out_lines), 2)
 306             self.assertEqual(len(err_lines), 1)
 307             self.assertEqual(err_lines[-1], "error: cannot format e1: boom")
 308             self.assertEqual(
 309                 unstyle(str(report)),
 310                 "1 file reformatted, 1 file left unchanged, "
 311                 "1 file failed to reformat.",
 312             )
 313             self.assertEqual(report.return_code, 123)
 314             report.done(Path("f3"), changed=True)
 315             self.assertEqual(len(out_lines), 3)
 316             self.assertEqual(len(err_lines), 1)
 317             self.assertEqual(out_lines[-1], "reformatted f3")
 318             self.assertEqual(
 319                 unstyle(str(report)),
 320                 "2 files reformatted, 1 file left unchanged, "
 321                 "1 file failed to reformat.",
 322             )
 323             self.assertEqual(report.return_code, 123)
 324             report.failed(Path("e2"), "boom")
 325             self.assertEqual(len(out_lines), 3)
 326             self.assertEqual(len(err_lines), 2)
 327             self.assertEqual(err_lines[-1], "error: cannot format e2: boom")
 328             self.assertEqual(
 329                 unstyle(str(report)),
 330                 "2 files reformatted, 1 file left unchanged, "
 331                 "2 files failed to reformat.",
 332             )
 333             self.assertEqual(report.return_code, 123)
 334             report.done(Path("f4"), changed=False)
 335             self.assertEqual(len(out_lines), 4)
 336             self.assertEqual(len(err_lines), 2)
 337             self.assertEqual(out_lines[-1], "f4 already well formatted, good job.")
 338             self.assertEqual(
 339                 unstyle(str(report)),
 340                 "2 files reformatted, 2 files left unchanged, "
 341                 "2 files failed to reformat.",
 342             )
 343             self.assertEqual(report.return_code, 123)
 344             report.check = True
 345             self.assertEqual(
 346                 unstyle(str(report)),
 347                 "2 files would be reformatted, 2 files would be left unchanged, "
 348                 "2 files would fail to reformat.",
 349             )
 350
 351     def test_is_python36(self) -> None:
 352         node = black.lib2to3_parse("def f(*, arg): ...\n")
 353         self.assertFalse(black.is_python36(node))
 354         node = black.lib2to3_parse("def f(*, arg,): ...\n")
 355         self.assertTrue(black.is_python36(node))
 356         node = black.lib2to3_parse("def f(*, arg): f'string'\n")
 357         self.assertTrue(black.is_python36(node))
 358         source, expected = read_data("function")
 359         node = black.lib2to3_parse(source)
 360         self.assertTrue(black.is_python36(node))
 361         node = black.lib2to3_parse(expected)
 362         self.assertTrue(black.is_python36(node))
 363         source, expected = read_data("expression")
 364         node = black.lib2to3_parse(source)
 365         self.assertFalse(black.is_python36(node))
 366         node = black.lib2to3_parse(expected)
 367         self.assertFalse(black.is_python36(node))
 368
 369     def test_debug_visitor(self) -> None:
 370         source, _ = read_data("debug_visitor.py")
 371         expected, _ = read_data("debug_visitor.out")
 372         out_lines = []
 373         err_lines = []
 374
 375         def out(msg: str, **kwargs: Any) -> None:
 376             out_lines.append(msg)
 377
 378         def err(msg: str, **kwargs: Any) -> None:
 379             err_lines.append(msg)
 380
 381         with patch("black.out", out), patch("black.err", err):
 382             black.DebugVisitor.show(source)
 383         actual = "\n".join(out_lines) + "\n"
 384         log_name = ""
 385         if expected != actual:
 386             log_name = black.dump_to_file(*out_lines)
 387         self.assertEqual(
 388             expected,
 389             actual,
 390             f"AST print out is different. Actual version dumped to {log_name}",
 391         )
 392
 393
 394 if __name__ == "__main__":
 395     unittest.main()