Extract formatting tests (#1785)

* Update test versions

* Use parametrize to remove tests duplications

* Extract sources format tests

* Fix mypy errors

* Fix .travis.yml

diff --git a/.travis.yml b/.travis.yml
index 86cf24df51bf6f2105dc97a743c794350ecd7f2c..f035343c6fb3c2f1c8786e0ed1ee040637b86a1b 100644 (file)
--- a/.travis.yml
+++ b/.travis.yml
@@ -4,9 +4,9 @@ cache:
   directories:
     - $HOME/.cache/pre-commit
 env:
-  - TEST_CMD="coverage run -m unittest"
+  - TEST_CMD="tox -e py"
 install:
-  - pip install coverage coveralls pre-commit
+  - pip install coverage coveralls pre-commit tox
   - pip install -e '.[d]'
 script:
   - $TEST_CMD

diff --git a/test_requirements.txt b/test_requirements.txt
index 999d05c01067d33d79fcfc3cad302784f5d6b666..3e65cdb669fb6aa970ab1a0eaba68a7b099ff9d9 100644 (file)
--- a/test_requirements.txt
+++ b/test_requirements.txt
@@ -1,4 +1,5 @@
-pytest >= 6.0.1
-pytest-mock >= 3.2.0
-pytest-cases >= 2.1.2
-coverage >= 5.2.1
\ No newline at end of file
+pytest >= 6.1.1
+pytest-mock >= 3.3.1
+pytest-cases >= 2.3.0
+coverage >= 5.3
+parameterized >= 0.7.4
\ No newline at end of file

diff --git a/tests/test_black.py b/tests/test_black.py
index 7927b368b5d0fc7d7141875db1933175b261b240..b0cf6ed5caa490ed4f9af71c24e451dedc24d071 100644 (file)
--- a/tests/test_black.py
+++ b/tests/test_black.py
@@ -5,7 +5,6 @@ import logging
 from concurrent.futures import ThreadPoolExecutor
 from contextlib import contextmanager
 from dataclasses import replace
-from functools import partial
 import inspect
 from io import BytesIO, TextIOWrapper
 import os
@@ -38,13 +37,19 @@ from black import Feature, TargetVersion
 from pathspec import PathSpec
 
 # Import other test classes
-from tests.util import THIS_DIR, read_data, DETERMINISTIC_HEADER
+from tests.util import (
+    THIS_DIR,
+    read_data,
+    DETERMINISTIC_HEADER,
+    BlackBaseTestCase,
+    DEFAULT_MODE,
+    fs,
+    ff,
+    dump_to_stderr,
+)
 from .test_primer import PrimerCLITests  # noqa: F401
 
 
-DEFAULT_MODE = black.FileMode(experimental_string_processing=True)
-ff = partial(black.format_file_in_place, mode=DEFAULT_MODE, fast=True)
-fs = partial(black.format_str, mode=DEFAULT_MODE)
 THIS_FILE = Path(__file__)
 PY36_VERSIONS = {
     TargetVersion.PY36,
@@ -57,10 +62,6 @@ T = TypeVar("T")
 R = TypeVar("R")
 
 
-def dump_to_stderr(*output: str) -> str:
-    return "\n" + "\n".join(output) + "\n"
-
-
 @contextmanager
 def cache_dir(exists: bool = True) -> Iterator[Path]:
     with TemporaryDirectory() as workspace:
@@ -122,29 +123,7 @@ class BlackRunner(CliRunner):
                 sys.stderr = hold_stderr
 
 
-class BlackTestCase(unittest.TestCase):
-    maxDiff = None
-    _diffThreshold = 2 ** 20
-
-    def assertFormatEqual(self, expected: str, actual: str) -> None:
-        if actual != expected and not os.environ.get("SKIP_AST_PRINT"):
-            bdv: black.DebugVisitor[Any]
-            black.out("Expected tree:", fg="green")
-            try:
-                exp_node = black.lib2to3_parse(expected)
-                bdv = black.DebugVisitor()
-                list(bdv.visit(exp_node))
-            except Exception as ve:
-                black.err(str(ve))
-            black.out("Actual tree:", fg="red")
-            try:
-                exp_node = black.lib2to3_parse(actual)
-                bdv = black.DebugVisitor()
-                list(bdv.visit(exp_node))
-            except Exception as ve:
-                black.err(str(ve))
-        self.assertMultiLineEqual(expected, actual)
-
+class BlackTestCase(BlackBaseTestCase):
     def invokeBlack(
         self, args: List[str], exit_code: int = 0, ignore_config: bool = True
     ) -> None:
@@ -163,16 +142,6 @@ class BlackTestCase(unittest.TestCase):
             ),
         )
 
-    @patch("black.dump_to_file", dump_to_stderr)
-    def checkSourceFile(self, name: str, mode: black.FileMode = DEFAULT_MODE) -> None:
-        path = THIS_DIR.parent / name
-        source, expected = read_data(str(path), data=False)
-        actual = fs(source, mode=mode)
-        self.assertFormatEqual(expected, actual)
-        black.assert_equivalent(source, actual)
-        black.assert_stable(source, actual, mode)
-        self.assertFalse(ff(path))
-
     @patch("black.dump_to_file", dump_to_stderr)
     def test_empty(self) -> None:
         source = expected = ""
@@ -192,48 +161,6 @@ class BlackTestCase(unittest.TestCase):
             os.unlink(tmp_file)
         self.assertFormatEqual(expected, actual)
 
-    def test_run_on_test_black(self) -> None:
-        self.checkSourceFile("tests/test_black.py")
-
-    def test_run_on_test_blackd(self) -> None:
-        self.checkSourceFile("tests/test_blackd.py")
-
-    def test_black(self) -> None:
-        self.checkSourceFile("src/black/__init__.py")
-
-    def test_pygram(self) -> None:
-        self.checkSourceFile("src/blib2to3/pygram.py")
-
-    def test_pytree(self) -> None:
-        self.checkSourceFile("src/blib2to3/pytree.py")
-
-    def test_conv(self) -> None:
-        self.checkSourceFile("src/blib2to3/pgen2/conv.py")
-
-    def test_driver(self) -> None:
-        self.checkSourceFile("src/blib2to3/pgen2/driver.py")
-
-    def test_grammar(self) -> None:
-        self.checkSourceFile("src/blib2to3/pgen2/grammar.py")
-
-    def test_literals(self) -> None:
-        self.checkSourceFile("src/blib2to3/pgen2/literals.py")
-
-    def test_parse(self) -> None:
-        self.checkSourceFile("src/blib2to3/pgen2/parse.py")
-
-    def test_pgen(self) -> None:
-        self.checkSourceFile("src/blib2to3/pgen2/pgen.py")
-
-    def test_tokenize(self) -> None:
-        self.checkSourceFile("src/blib2to3/pgen2/tokenize.py")
-
-    def test_token(self) -> None:
-        self.checkSourceFile("src/blib2to3/pgen2/token.py")
-
-    def test_setup(self) -> None:
-        self.checkSourceFile("setup.py")
-
     def test_piping(self) -> None:
         source, expected = read_data("src/black/__init__", data=False)
         result = BlackRunner().invoke(
@@ -291,22 +218,6 @@ class BlackTestCase(unittest.TestCase):
         self.assertIn("\033[31m", actual)
         self.assertIn("\033[0m", actual)
 
-    @patch("black.dump_to_file", dump_to_stderr)
-    def test_function(self) -> None:
-        source, expected = read_data("function")
-        actual = fs(source)
-        self.assertFormatEqual(expected, actual)
-        black.assert_equivalent(source, actual)
-        black.assert_stable(source, actual, DEFAULT_MODE)
-
-    @patch("black.dump_to_file", dump_to_stderr)
-    def test_function2(self) -> None:
-        source, expected = read_data("function2")
-        actual = fs(source)
-        self.assertFormatEqual(expected, actual)
-        black.assert_equivalent(source, actual)
-        black.assert_stable(source, actual, DEFAULT_MODE)
-
     @patch("black.dump_to_file", dump_to_stderr)
     def _test_wip(self) -> None:
         source, expected = read_data("wip")
@@ -322,14 +233,6 @@ class BlackTestCase(unittest.TestCase):
         black.assert_equivalent(source, actual)
         black.assert_stable(source, actual, black.FileMode())
 
-    @patch("black.dump_to_file", dump_to_stderr)
-    def test_function_trailing_comma(self) -> None:
-        source, expected = read_data("function_trailing_comma")
-        actual = fs(source)
-        self.assertFormatEqual(expected, actual)
-        black.assert_equivalent(source, actual)
-        black.assert_stable(source, actual, DEFAULT_MODE)
-
     @unittest.expectedFailure
     @patch("black.dump_to_file", dump_to_stderr)
     def test_trailing_comma_optional_parens_stability1(self) -> None:
@@ -351,14 +254,6 @@ class BlackTestCase(unittest.TestCase):
         actual = fs(source)
         black.assert_stable(source, actual, DEFAULT_MODE)
 
-    @patch("black.dump_to_file", dump_to_stderr)
-    def test_expression(self) -> None:
-        source, expected = read_data("expression")
-        actual = fs(source)
-        self.assertFormatEqual(expected, actual)
-        black.assert_equivalent(source, actual)
-        black.assert_stable(source, actual, DEFAULT_MODE)
-
     @patch("black.dump_to_file", dump_to_stderr)
     def test_pep_572(self) -> None:
         source, expected = read_data("pep_572")
@@ -434,14 +329,6 @@ class BlackTestCase(unittest.TestCase):
         self.assertIn("\033[31m", actual)
         self.assertIn("\033[0m", actual)
 
-    @patch("black.dump_to_file", dump_to_stderr)
-    def test_fstring(self) -> None:
-        source, expected = read_data("fstring")
-        actual = fs(source)
-        self.assertFormatEqual(expected, actual)
-        black.assert_equivalent(source, actual)
-        black.assert_stable(source, actual, DEFAULT_MODE)
-
     @patch("black.dump_to_file", dump_to_stderr)
     def test_pep_570(self) -> None:
         source, expected = read_data("pep_570")
@@ -472,14 +359,6 @@ class BlackTestCase(unittest.TestCase):
         black.assert_equivalent(source, not_normalized)
         black.assert_stable(source, not_normalized, mode=mode)
 
-    @patch("black.dump_to_file", dump_to_stderr)
-    def test_docstring(self) -> None:
-        source, expected = read_data("docstring")
-        actual = fs(source)
-        self.assertFormatEqual(expected, actual)
-        black.assert_equivalent(source, actual)
-        black.assert_stable(source, actual, DEFAULT_MODE)
-
     @patch("black.dump_to_file", dump_to_stderr)
     def test_docstring_no_string_normalization(self) -> None:
         """Like test_docstring but with string normalization off."""
@@ -490,14 +369,6 @@ class BlackTestCase(unittest.TestCase):
         black.assert_equivalent(source, actual)
         black.assert_stable(source, actual, mode)
 
-    def test_long_strings(self) -> None:
-        """Tests for splitting long strings."""
-        source, expected = read_data("long_strings")
-        actual = fs(source)
-        self.assertFormatEqual(expected, actual)
-        black.assert_equivalent(source, actual)
-        black.assert_stable(source, actual, DEFAULT_MODE)
-
     def test_long_strings_flag_disabled(self) -> None:
         """Tests for turning off the string processing logic."""
         source, expected = read_data("long_strings_flag_disabled")
@@ -506,162 +377,6 @@ class BlackTestCase(unittest.TestCase):
         self.assertFormatEqual(expected, actual)
         black.assert_stable(expected, actual, mode)
 
-    @patch("black.dump_to_file", dump_to_stderr)
-    def test_long_strings__edge_case(self) -> None:
-        """Edge-case tests for splitting long strings."""
-        source, expected = read_data("long_strings__edge_case")
-        actual = fs(source)
-        self.assertFormatEqual(expected, actual)
-        black.assert_equivalent(source, actual)
-        black.assert_stable(source, actual, DEFAULT_MODE)
-
-    @patch("black.dump_to_file", dump_to_stderr)
-    def test_long_strings__regression(self) -> None:
-        """Regression tests for splitting long strings."""
-        source, expected = read_data("long_strings__regression")
-        actual = fs(source)
-        self.assertFormatEqual(expected, actual)
-        black.assert_equivalent(source, actual)
-        black.assert_stable(source, actual, DEFAULT_MODE)
-
-    @patch("black.dump_to_file", dump_to_stderr)
-    def test_slices(self) -> None:
-        source, expected = read_data("slices")
-        actual = fs(source)
-        self.assertFormatEqual(expected, actual)
-        black.assert_equivalent(source, actual)
-        black.assert_stable(source, actual, DEFAULT_MODE)
-
-    @patch("black.dump_to_file", dump_to_stderr)
-    def test_percent_precedence(self) -> None:
-        source, expected = read_data("percent_precedence")
-        actual = fs(source)
-        self.assertFormatEqual(expected, actual)
-        black.assert_equivalent(source, actual)
-        black.assert_stable(source, actual, DEFAULT_MODE)
-
-    @patch("black.dump_to_file", dump_to_stderr)
-    def test_comments(self) -> None:
-        source, expected = read_data("comments")
-        actual = fs(source)
-        self.assertFormatEqual(expected, actual)
-        black.assert_equivalent(source, actual)
-        black.assert_stable(source, actual, DEFAULT_MODE)
-
-    @patch("black.dump_to_file", dump_to_stderr)
-    def test_comments2(self) -> None:
-        source, expected = read_data("comments2")
-        actual = fs(source)
-        self.assertFormatEqual(expected, actual)
-        black.assert_equivalent(source, actual)
-        black.assert_stable(source, actual, DEFAULT_MODE)
-
-    @patch("black.dump_to_file", dump_to_stderr)
-    def test_comments3(self) -> None:
-        source, expected = read_data("comments3")
-        actual = fs(source)
-        self.assertFormatEqual(expected, actual)
-        black.assert_equivalent(source, actual)
-        black.assert_stable(source, actual, DEFAULT_MODE)
-
-    @patch("black.dump_to_file", dump_to_stderr)
-    def test_comments4(self) -> None:
-        source, expected = read_data("comments4")
-        actual = fs(source)
-        self.assertFormatEqual(expected, actual)
-        black.assert_equivalent(source, actual)
-        black.assert_stable(source, actual, DEFAULT_MODE)
-
-    @patch("black.dump_to_file", dump_to_stderr)
-    def test_comments5(self) -> None:
-        source, expected = read_data("comments5")
-        actual = fs(source)
-        self.assertFormatEqual(expected, actual)
-        black.assert_equivalent(source, actual)
-        black.assert_stable(source, actual, DEFAULT_MODE)
-
-    @patch("black.dump_to_file", dump_to_stderr)
-    def test_comments6(self) -> None:
-        source, expected = read_data("comments6")
-        actual = fs(source)
-        self.assertFormatEqual(expected, actual)
-        black.assert_equivalent(source, actual)
-        black.assert_stable(source, actual, DEFAULT_MODE)
-
-    @patch("black.dump_to_file", dump_to_stderr)
-    def test_comments7(self) -> None:
-        source, expected = read_data("comments7")
-        mode = replace(DEFAULT_MODE, target_versions={black.TargetVersion.PY38})
-        actual = fs(source, mode=mode)
-        self.assertFormatEqual(expected, actual)
-        black.assert_equivalent(source, actual)
-        black.assert_stable(source, actual, DEFAULT_MODE)
-
-    @patch("black.dump_to_file", dump_to_stderr)
-    def test_comment_after_escaped_newline(self) -> None:
-        source, expected = read_data("comment_after_escaped_newline")
-        actual = fs(source)
-        self.assertFormatEqual(expected, actual)
-        black.assert_equivalent(source, actual)
-        black.assert_stable(source, actual, DEFAULT_MODE)
-
-    @patch("black.dump_to_file", dump_to_stderr)
-    def test_cantfit(self) -> None:
-        source, expected = read_data("cantfit")
-        actual = fs(source)
-        self.assertFormatEqual(expected, actual)
-        black.assert_equivalent(source, actual)
-        black.assert_stable(source, actual, DEFAULT_MODE)
-
-    @patch("black.dump_to_file", dump_to_stderr)
-    def test_import_spacing(self) -> None:
-        source, expected = read_data("import_spacing")
-        actual = fs(source)
-        self.assertFormatEqual(expected, actual)
-        black.assert_equivalent(source, actual)
-        black.assert_stable(source, actual, DEFAULT_MODE)
-
-    @patch("black.dump_to_file", dump_to_stderr)
-    def test_composition(self) -> None:
-        source, expected = read_data("composition")
-        actual = fs(source)
-        self.assertFormatEqual(expected, actual)
-        black.assert_equivalent(source, actual)
-        black.assert_stable(source, actual, DEFAULT_MODE)
-
-    @patch("black.dump_to_file", dump_to_stderr)
-    def test_composition_no_trailing_comma(self) -> None:
-        source, expected = read_data("composition_no_trailing_comma")
-        mode = replace(DEFAULT_MODE, target_versions={black.TargetVersion.PY38})
-        actual = fs(source, mode=mode)
-        self.assertFormatEqual(expected, actual)
-        black.assert_equivalent(source, actual)
-        black.assert_stable(source, actual, DEFAULT_MODE)
-
-    @patch("black.dump_to_file", dump_to_stderr)
-    def test_empty_lines(self) -> None:
-        source, expected = read_data("empty_lines")
-        actual = fs(source)
-        self.assertFormatEqual(expected, actual)
-        black.assert_equivalent(source, actual)
-        black.assert_stable(source, actual, DEFAULT_MODE)
-
-    @patch("black.dump_to_file", dump_to_stderr)
-    def test_remove_parens(self) -> None:
-        source, expected = read_data("remove_parens")
-        actual = fs(source)
-        self.assertFormatEqual(expected, actual)
-        black.assert_equivalent(source, actual)
-        black.assert_stable(source, actual, DEFAULT_MODE)
-
-    @patch("black.dump_to_file", dump_to_stderr)
-    def test_string_prefixes(self) -> None:
-        source, expected = read_data("string_prefixes")
-        actual = fs(source)
-        self.assertFormatEqual(expected, actual)
-        black.assert_equivalent(source, actual)
-        black.assert_stable(source, actual, DEFAULT_MODE)
-
     @patch("black.dump_to_file", dump_to_stderr)
     def test_numeric_literals(self) -> None:
         source, expected = read_data("numeric_literals")
@@ -680,21 +395,6 @@ class BlackTestCase(unittest.TestCase):
         black.assert_equivalent(source, actual)
         black.assert_stable(source, actual, mode)
 
-    @patch("black.dump_to_file", dump_to_stderr)
-    def test_numeric_literals_py2(self) -> None:
-        source, expected = read_data("numeric_literals_py2")
-        actual = fs(source)
-        self.assertFormatEqual(expected, actual)
-        black.assert_stable(source, actual, DEFAULT_MODE)
-
-    @patch("black.dump_to_file", dump_to_stderr)
-    def test_python2(self) -> None:
-        source, expected = read_data("python2")
-        actual = fs(source)
-        self.assertFormatEqual(expected, actual)
-        black.assert_equivalent(source, actual)
-        black.assert_stable(source, actual, DEFAULT_MODE)
-
     @patch("black.dump_to_file", dump_to_stderr)
     def test_python2_print_function(self) -> None:
         source, expected = read_data("python2_print_function")
@@ -704,14 +404,6 @@ class BlackTestCase(unittest.TestCase):
         black.assert_equivalent(source, actual)
         black.assert_stable(source, actual, mode)
 
-    @patch("black.dump_to_file", dump_to_stderr)
-    def test_python2_unicode_literals(self) -> None:
-        source, expected = read_data("python2_unicode_literals")
-        actual = fs(source)
-        self.assertFormatEqual(expected, actual)
-        black.assert_equivalent(source, actual)
-        black.assert_stable(source, actual, DEFAULT_MODE)
-
     @patch("black.dump_to_file", dump_to_stderr)
     def test_stub(self) -> None:
         mode = replace(DEFAULT_MODE, is_pyi=True)
@@ -770,78 +462,6 @@ class BlackTestCase(unittest.TestCase):
             black.assert_equivalent(source, actual)
         black.assert_stable(source, actual, DEFAULT_MODE)
 
-    @patch("black.dump_to_file", dump_to_stderr)
-    def test_fmtonoff(self) -> None:
-        source, expected = read_data("fmtonoff")
-        actual = fs(source)
-        self.assertFormatEqual(expected, actual)
-        black.assert_equivalent(source, actual)
-        black.assert_stable(source, actual, DEFAULT_MODE)
-
-    @patch("black.dump_to_file", dump_to_stderr)
-    def test_fmtonoff2(self) -> None:
-        source, expected = read_data("fmtonoff2")
-        actual = fs(source)
-        self.assertFormatEqual(expected, actual)
-        black.assert_equivalent(source, actual)
-        black.assert_stable(source, actual, DEFAULT_MODE)
-
-    @patch("black.dump_to_file", dump_to_stderr)
-    def test_fmtonoff3(self) -> None:
-        source, expected = read_data("fmtonoff3")
-        actual = fs(source)
-        self.assertFormatEqual(expected, actual)
-        black.assert_equivalent(source, actual)
-        black.assert_stable(source, actual, DEFAULT_MODE)
-
-    @patch("black.dump_to_file", dump_to_stderr)
-    def test_fmtonoff4(self) -> None:
-        source, expected = read_data("fmtonoff4")
-        actual = fs(source)
-        self.assertFormatEqual(expected, actual)
-        black.assert_equivalent(source, actual)
-        black.assert_stable(source, actual, DEFAULT_MODE)
-
-    @patch("black.dump_to_file", dump_to_stderr)
-    def test_remove_empty_parentheses_after_class(self) -> None:
-        source, expected = read_data("class_blank_parentheses")
-        actual = fs(source)
-        self.assertFormatEqual(expected, actual)
-        black.assert_equivalent(source, actual)
-        black.assert_stable(source, actual, DEFAULT_MODE)
-
-    @patch("black.dump_to_file", dump_to_stderr)
-    def test_new_line_between_class_and_code(self) -> None:
-        source, expected = read_data("class_methods_new_line")
-        actual = fs(source)
-        self.assertFormatEqual(expected, actual)
-        black.assert_equivalent(source, actual)
-        black.assert_stable(source, actual, DEFAULT_MODE)
-
-    @patch("black.dump_to_file", dump_to_stderr)
-    def test_bracket_match(self) -> None:
-        source, expected = read_data("bracketmatch")
-        actual = fs(source)
-        self.assertFormatEqual(expected, actual)
-        black.assert_equivalent(source, actual)
-        black.assert_stable(source, actual, DEFAULT_MODE)
-
-    @patch("black.dump_to_file", dump_to_stderr)
-    def test_tuple_assign(self) -> None:
-        source, expected = read_data("tupleassign")
-        actual = fs(source)
-        self.assertFormatEqual(expected, actual)
-        black.assert_equivalent(source, actual)
-        black.assert_stable(source, actual, DEFAULT_MODE)
-
-    @patch("black.dump_to_file", dump_to_stderr)
-    def test_beginning_backslash(self) -> None:
-        source, expected = read_data("beginning_backslash")
-        actual = fs(source)
-        self.assertFormatEqual(expected, actual)
-        black.assert_equivalent(source, actual)
-        black.assert_stable(source, actual, DEFAULT_MODE)
-
     def test_tab_comment_indentation(self) -> None:
         contents_tab = "if 1:\n\tif 2:\n\t\tpass\n\t# comment\n\tpass\n"
         contents_spc = "if 1:\n    if 2:\n        pass\n    # comment\n    pass\n"
@@ -1569,13 +1189,6 @@ class BlackTestCase(unittest.TestCase):
             two = black.read_cache(short_mode)
             self.assertNotIn(path, two)
 
-    def test_tricky_unicode_symbols(self) -> None:
-        source, expected = read_data("tricky_unicode_symbols")
-        actual = fs(source)
-        self.assertFormatEqual(expected, actual)
-        black.assert_equivalent(source, actual)
-        black.assert_stable(source, actual, DEFAULT_MODE)
-
     def test_single_file_force_pyi(self) -> None:
         pyi_mode = replace(DEFAULT_MODE, is_pyi=True)
         contents, expected = read_data("force_pyi")
@@ -1672,13 +1285,6 @@ class BlackTestCase(unittest.TestCase):
                 self.assertIn(path, pyi_cache)
                 self.assertNotIn(path, normal_cache)
 
-    def test_collections(self) -> None:
-        source, expected = read_data("collections")
-        actual = fs(source)
-        self.assertFormatEqual(expected, actual)
-        black.assert_equivalent(source, actual)
-        black.assert_stable(source, actual, DEFAULT_MODE)
-
     def test_pipe_force_py36(self) -> None:
         source, expected = read_data("force_py36")
         result = CliRunner().invoke(

diff --git a/tests/test_format.py b/tests/test_format.py
new file mode 100644 (file)
index 0000000..e467770
--- /dev/null
+++ b/tests/test_format.py
@@ -0,0 +1,98 @@
+from unittest.mock import patch
+
+import black
+from parameterized import parameterized
+
+from tests.util import (
+    BlackBaseTestCase,
+    fs,
+    ff,
+    DEFAULT_MODE,
+    dump_to_stderr,
+    read_data,
+    THIS_DIR,
+)
+
+SIMPLE_CASES = [
+    "beginning_backslash",
+    "bracketmatch",
+    "cantfit",
+    "class_blank_parentheses",
+    "class_methods_new_line",
+    "collections",
+    "comments",
+    "comments2",
+    "comments3",
+    "comments4",
+    "comments5",
+    "comments6",
+    "comments7",
+    "comment_after_escaped_newline",
+    "composition",
+    "composition_no_trailing_comma",
+    "docstring",
+    "empty_lines",
+    "expression",
+    "fmtonoff",
+    "fmtonoff2",
+    "fmtonoff3",
+    "fmtonoff4",
+    "fstring",
+    "function",
+    "function2",
+    "function_trailing_comma",
+    "import_spacing",
+    "long_strings",
+    "long_strings__edge_case",
+    "long_strings__regression",
+    "numeric_literals_py2",
+    "percent_precedence",
+    "python2",
+    "python2_unicode_literals",
+    "remove_parens",
+    "slices",
+    "string_prefixes",
+    "tricky_unicode_symbols",
+    "tupleassign",
+]
+
+
+SOURCES = [
+    "tests/test_black.py",
+    "tests/test_format.py",
+    "tests/test_blackd.py",
+    "src/black/__init__.py",
+    "src/blib2to3/pygram.py",
+    "src/blib2to3/pytree.py",
+    "src/blib2to3/pgen2/conv.py",
+    "src/blib2to3/pgen2/driver.py",
+    "src/blib2to3/pgen2/grammar.py",
+    "src/blib2to3/pgen2/literals.py",
+    "src/blib2to3/pgen2/parse.py",
+    "src/blib2to3/pgen2/pgen.py",
+    "src/blib2to3/pgen2/tokenize.py",
+    "src/blib2to3/pgen2/token.py",
+    "setup.py",
+]
+
+
+class TestSimpleFormat(BlackBaseTestCase):
+    @parameterized.expand(SIMPLE_CASES)
+    @patch("black.dump_to_file", dump_to_stderr)
+    def test_simple_format(self, filename: str) -> None:
+        source, expected = read_data(filename)
+        actual = fs(source)
+        self.assertFormatEqual(expected, actual)
+        black.assert_equivalent(source, actual)
+        black.assert_stable(source, actual, DEFAULT_MODE)
+
+    @parameterized.expand(SOURCES)
+    @patch("black.dump_to_file", dump_to_stderr)
+    def test_source_is_formatted(self, filename: str) -> None:
+        path = THIS_DIR.parent / filename
+        source, expected = read_data(str(path), data=False)
+        actual = fs(source, mode=DEFAULT_MODE)
+        self.assertFormatEqual(expected, actual)
+        black.assert_equivalent(source, actual)
+        black.assert_stable(source, actual, DEFAULT_MODE)
+        self.assertFalse(ff(path))

diff --git a/tests/util.py b/tests/util.py
index 9c3d3cbc99d031e2a1d6cc556bd0b4ca0af878c0..da65ed0cc931ef00c71aab999c8b56fe750dd4fa 100644 (file)
--- a/tests/util.py
+++ b/tests/util.py
@@ -1,7 +1,10 @@
+import os
 import unittest
 from contextlib import contextmanager
 from pathlib import Path
-from typing import List, Tuple, Iterator
+from typing import List, Tuple, Iterator, Any
+import black
+from functools import partial
 
 THIS_DIR = Path(__file__).parent
 PROJECT_ROOT = THIS_DIR.parent
@@ -9,6 +12,39 @@ EMPTY_LINE = "# EMPTY LINE WITH WHITESPACE" + " (this comment will be removed)"
 DETERMINISTIC_HEADER = "[Deterministic header]"
 
 
+DEFAULT_MODE = black.FileMode(experimental_string_processing=True)
+ff = partial(black.format_file_in_place, mode=DEFAULT_MODE, fast=True)
+fs = partial(black.format_str, mode=DEFAULT_MODE)
+
+
+def dump_to_stderr(*output: str) -> str:
+    return "\n" + "\n".join(output) + "\n"
+
+
+class BlackBaseTestCase(unittest.TestCase):
+    maxDiff = None
+    _diffThreshold = 2 ** 20
+
+    def assertFormatEqual(self, expected: str, actual: str) -> None:
+        if actual != expected and not os.environ.get("SKIP_AST_PRINT"):
+            bdv: black.DebugVisitor[Any]
+            black.out("Expected tree:", fg="green")
+            try:
+                exp_node = black.lib2to3_parse(expected)
+                bdv = black.DebugVisitor()
+                list(bdv.visit(exp_node))
+            except Exception as ve:
+                black.err(str(ve))
+            black.out("Actual tree:", fg="red")
+            try:
+                exp_node = black.lib2to3_parse(actual)
+                bdv = black.DebugVisitor()
+                list(bdv.visit(exp_node))
+            except Exception as ve:
+                black.err(str(ve))
+        self.assertMultiLineEqual(expected, actual)
+
+
 @contextmanager
 def skip_if_exception(e: str) -> Iterator[None]:
     try:
@@ -24,11 +60,15 @@ def read_data(name: str, data: bool = True) -> Tuple[str, str]:
     """read_data('test_name') -> 'input', 'output'"""
     if not name.endswith((".py", ".pyi", ".out", ".diff")):
         name += ".py"
-    _input: List[str] = []
-    _output: List[str] = []
     base_dir = THIS_DIR / "data" if data else PROJECT_ROOT
-    with open(base_dir / name, "r", encoding="utf8") as test:
+    return read_data_from_file(base_dir / name)
+
+
+def read_data_from_file(file_name: Path) -> Tuple[str, str]:
+    with open(file_name, "r", encoding="utf8") as test:
         lines = test.readlines()
+    _input: List[str] = []
+    _output: List[str] = []
     result = _input
     for line in lines:
         line = line.replace(EMPTY_LINE, "")