As long as it's black (#1893)

[etc/vim.git] / tests / test_black.py

diff --git a/tests/test_black.py b/tests/test_black.py
index edcf7208b46aa685166dad061640cb8531c5717e..a688c8780efe682530d11ccf55c9995eea8608a8 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 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
 import inspect
 from io import BytesIO, TextIOWrapper
 import os


@@ -22,7 +21,6 @@ from typing import (
     Dict,
     Generator,
     List,
     Dict,
     Generator,
     List,

-    Tuple,

     Iterator,
     TypeVar,
 )
     Iterator,
     TypeVar,
 )


@@ -36,63 +34,34 @@ from click.testing import CliRunner
 import black
 from black import Feature, TargetVersion
 
 import black
 from black import Feature, TargetVersion
 

-try:
-    import blackd
-    from aiohttp.test_utils import AioHTTPTestCase, unittest_run_loop
-    from aiohttp import web
-except ImportError:
-    has_blackd_deps = False
-else:
-    has_blackd_deps = True
-

 from pathspec import PathSpec
 
 # Import other test classes
 from pathspec import PathSpec
 
 # Import other test classes

+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
 
 
 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__)
 THIS_FILE = Path(__file__)

-THIS_DIR = THIS_FILE.parent
-PROJECT_ROOT = THIS_DIR.parent
-DETERMINISTIC_HEADER = "[Deterministic header]"
-EMPTY_LINE = "# EMPTY LINE WITH WHITESPACE" + " (this comment will be removed)"
-PY36_ARGS = [
-    f"--target-version={version.name.lower()}" for version in black.PY36_VERSIONS
-]
+PY36_VERSIONS = {
+    TargetVersion.PY36,
+    TargetVersion.PY37,
+    TargetVersion.PY38,
+    TargetVersion.PY39,
+}
+PY36_ARGS = [f"--target-version={version.name.lower()}" for version in PY36_VERSIONS]

 T = TypeVar("T")
 R = TypeVar("R")
 
 
 T = TypeVar("T")
 R = TypeVar("R")
 
 

-def dump_to_stderr(*output: str) -> str:
-    return "\n" + "\n".join(output) + "\n"
-
-
-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:
-        lines = test.readlines()
-    result = _input
-    for line in lines:
-        line = line.replace(EMPTY_LINE, "")
-        if line.rstrip() == "# output":
-            result = _output
-            continue
-
-        result.append(line)
-    if _input and not _output:
-        # If there's no output marker, treat the entire file as already pre-formatted.
-        _output = _input[:]
-    return "".join(_input).strip() + "\n", "".join(_output).strip() + "\n"
-
-

 @contextmanager
 def cache_dir(exists: bool = True) -> Iterator[Path]:
     with TemporaryDirectory() as workspace:
 @contextmanager
 def cache_dir(exists: bool = True) -> Iterator[Path]:
     with TemporaryDirectory() as workspace:


@@ -115,17 +84,6 @@ def event_loop() -> Iterator[None]:
         loop.close()
 
 
         loop.close()
 
 

-@contextmanager
-def skip_if_exception(e: str) -> Iterator[None]:
-    try:
-        yield
-    except Exception as exc:
-        if exc.__class__.__name__ == e:
-            unittest.skip(f"Encountered expected exception {exc}, skipping")
-        else:
-            raise
-
-

 class FakeContext(click.Context):
     """A fake click Context for when calling functions that need it."""
 
 class FakeContext(click.Context):
     """A fake click Context for when calling functions that need it."""
 


@@ -165,29 +123,7 @@ class BlackRunner(CliRunner):
                 sys.stderr = hold_stderr
 
 
                 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:
     def invokeBlack(
         self, args: List[str], exit_code: int = 0, ignore_config: bool = True
     ) -> None:


@@ -206,16 +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 = ""
     @patch("black.dump_to_file", dump_to_stderr)
     def test_empty(self) -> None:
         source = expected = ""


@@ -235,45 +161,6 @@ class BlackTestCase(unittest.TestCase):
             os.unlink(tmp_file)
         self.assertFormatEqual(expected, actual)
 
             os.unlink(tmp_file)
         self.assertFormatEqual(expected, actual)
 

-    def test_self(self) -> None:
-        self.checkSourceFile("tests/test_black.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(
     def test_piping(self) -> None:
         source, expected = read_data("src/black/__init__", data=False)
         result = BlackRunner().invoke(


@@ -331,22 +218,6 @@ class BlackTestCase(unittest.TestCase):
         self.assertIn("\033[31m", actual)
         self.assertIn("\033[0m", actual)
 
         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")
     @patch("black.dump_to_file", dump_to_stderr)
     def _test_wip(self) -> None:
         source, expected = read_data("wip")


@@ -362,14 +233,6 @@ class BlackTestCase(unittest.TestCase):
         black.assert_equivalent(source, actual)
         black.assert_stable(source, actual, black.FileMode())
 
         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:
     @unittest.expectedFailure
     @patch("black.dump_to_file", dump_to_stderr)
     def test_trailing_comma_optional_parens_stability1(self) -> None:


@@ -391,14 +254,6 @@ class BlackTestCase(unittest.TestCase):
         actual = fs(source)
         black.assert_stable(source, actual, DEFAULT_MODE)
 
         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")
     @patch("black.dump_to_file", dump_to_stderr)
     def test_pep_572(self) -> None:
         source, expected = read_data("pep_572")


@@ -474,14 +329,6 @@ class BlackTestCase(unittest.TestCase):
         self.assertIn("\033[31m", actual)
         self.assertIn("\033[0m", actual)
 
         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")
     @patch("black.dump_to_file", dump_to_stderr)
     def test_pep_570(self) -> None:
         source, expected = read_data("pep_570")


@@ -512,14 +359,6 @@ class BlackTestCase(unittest.TestCase):
         black.assert_equivalent(source, not_normalized)
         black.assert_stable(source, not_normalized, mode=mode)
 
         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."""
     @patch("black.dump_to_file", dump_to_stderr)
     def test_docstring_no_string_normalization(self) -> None:
         """Like test_docstring but with string normalization off."""


@@ -530,14 +369,6 @@ class BlackTestCase(unittest.TestCase):
         black.assert_equivalent(source, actual)
         black.assert_stable(source, actual, mode)
 
         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")
     def test_long_strings_flag_disabled(self) -> None:
         """Tests for turning off the string processing logic."""
         source, expected = read_data("long_strings_flag_disabled")


@@ -546,166 +377,10 @@ class BlackTestCase(unittest.TestCase):
         self.assertFormatEqual(expected, actual)
         black.assert_stable(expected, actual, mode)
 
         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")
     @patch("black.dump_to_file", dump_to_stderr)
     def test_numeric_literals(self) -> None:
         source, expected = read_data("numeric_literals")

-        mode = replace(DEFAULT_MODE, target_versions=black.PY36_VERSIONS)
+        mode = replace(DEFAULT_MODE, target_versions=PY36_VERSIONS)

         actual = fs(source, mode=mode)
         self.assertFormatEqual(expected, actual)
         black.assert_equivalent(source, actual)
         actual = fs(source, mode=mode)
         self.assertFormatEqual(expected, actual)
         black.assert_equivalent(source, actual)


@@ -714,27 +389,12 @@ class BlackTestCase(unittest.TestCase):
     @patch("black.dump_to_file", dump_to_stderr)
     def test_numeric_literals_ignoring_underscores(self) -> None:
         source, expected = read_data("numeric_literals_skip_underscores")
     @patch("black.dump_to_file", dump_to_stderr)
     def test_numeric_literals_ignoring_underscores(self) -> None:
         source, expected = read_data("numeric_literals_skip_underscores")

-        mode = replace(DEFAULT_MODE, target_versions=black.PY36_VERSIONS)
+        mode = replace(DEFAULT_MODE, target_versions=PY36_VERSIONS)

         actual = fs(source, mode=mode)
         self.assertFormatEqual(expected, actual)
         black.assert_equivalent(source, actual)
         black.assert_stable(source, actual, mode)
 
         actual = fs(source, mode=mode)
         self.assertFormatEqual(expected, actual)
         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")
     @patch("black.dump_to_file", dump_to_stderr)
     def test_python2_print_function(self) -> None:
         source, expected = read_data("python2_print_function")


@@ -744,14 +404,6 @@ class BlackTestCase(unittest.TestCase):
         black.assert_equivalent(source, actual)
         black.assert_stable(source, actual, mode)
 
         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)
     @patch("black.dump_to_file", dump_to_stderr)
     def test_stub(self) -> None:
         mode = replace(DEFAULT_MODE, is_pyi=True)


@@ -801,75 +453,13 @@ class BlackTestCase(unittest.TestCase):
         black.assert_stable(source, actual, DEFAULT_MODE)
 
     @patch("black.dump_to_file", dump_to_stderr)
         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")
+    def test_python39(self) -> None:
+        source, expected = read_data("python39")

         actual = fs(source)
         self.assertFormatEqual(expected, actual)
         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)
+        major, minor = sys.version_info[:2]
+        if major > 3 or (major == 3 and minor >= 9):
+            black.assert_equivalent(source, actual)

         black.assert_stable(source, actual, DEFAULT_MODE)
 
     def test_tab_comment_indentation(self) -> None:
         black.assert_stable(source, actual, DEFAULT_MODE)
 
     def test_tab_comment_indentation(self) -> None:


@@ -1212,6 +802,39 @@ class BlackTestCase(unittest.TestCase):
         black.lib2to3_parse(py3_only, {TargetVersion.PY36})
         black.lib2to3_parse(py3_only, {TargetVersion.PY27, TargetVersion.PY36})
 
         black.lib2to3_parse(py3_only, {TargetVersion.PY36})
         black.lib2to3_parse(py3_only, {TargetVersion.PY27, TargetVersion.PY36})
 

+    def test_get_features_used_decorator(self) -> None:
+        # Test the feature detection of new decorator syntax
+        # since this makes some test cases of test_get_features_used()
+        # fails if it fails, this is tested first so that a useful case
+        # is identified
+        simples, relaxed = read_data("decorators")
+        # skip explanation comments at the top of the file
+        for simple_test in simples.split("##")[1:]:
+            node = black.lib2to3_parse(simple_test)
+            decorator = str(node.children[0].children[0]).strip()
+            self.assertNotIn(
+                Feature.RELAXED_DECORATORS,
+                black.get_features_used(node),
+                msg=(
+                    f"decorator '{decorator}' follows python<=3.8 syntax"
+                    "but is detected as 3.9+"
+                    # f"The full node is\n{node!r}"
+                ),
+            )
+        # skip the '# output' comment at the top of the output part
+        for relaxed_test in relaxed.split("##")[1:]:
+            node = black.lib2to3_parse(relaxed_test)
+            decorator = str(node.children[0].children[0]).strip()
+            self.assertIn(
+                Feature.RELAXED_DECORATORS,
+                black.get_features_used(node),
+                msg=(
+                    f"decorator '{decorator}' uses python3.9+ syntax"
+                    "but is detected as python<=3.8"
+                    # f"The full node is\n{node!r}"
+                ),
+            )
+

     def test_get_features_used(self) -> None:
         node = black.lib2to3_parse("def f(*, arg): ...\n")
         self.assertEqual(black.get_features_used(node), set())
     def test_get_features_used(self) -> None:
         node = black.lib2to3_parse("def f(*, arg): ...\n")
         self.assertEqual(black.get_features_used(node), set())


@@ -1566,15 +1189,7 @@ class BlackTestCase(unittest.TestCase):
             two = black.read_cache(short_mode)
             self.assertNotIn(path, two)
 
             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:
     def test_single_file_force_pyi(self) -> None:

-        reg_mode = DEFAULT_MODE

         pyi_mode = replace(DEFAULT_MODE, is_pyi=True)
         contents, expected = read_data("force_pyi")
         with cache_dir() as workspace:
         pyi_mode = replace(DEFAULT_MODE, is_pyi=True)
         contents, expected = read_data("force_pyi")
         with cache_dir() as workspace:


@@ -1587,9 +1202,11 @@ class BlackTestCase(unittest.TestCase):
             # verify cache with --pyi is separate
             pyi_cache = black.read_cache(pyi_mode)
             self.assertIn(path, pyi_cache)
             # verify cache with --pyi is separate
             pyi_cache = black.read_cache(pyi_mode)
             self.assertIn(path, pyi_cache)

-            normal_cache = black.read_cache(reg_mode)
+            normal_cache = black.read_cache(DEFAULT_MODE)

             self.assertNotIn(path, normal_cache)
             self.assertNotIn(path, normal_cache)

-        self.assertEqual(actual, expected)
+        self.assertFormatEqual(expected, actual)
+        black.assert_equivalent(contents, actual)
+        black.assert_stable(contents, actual, pyi_mode)

 
     @event_loop()
     def test_multi_file_force_pyi(self) -> None:
 
     @event_loop()
     def test_multi_file_force_pyi(self) -> None:


@@ -1627,7 +1244,7 @@ class BlackTestCase(unittest.TestCase):
 
     def test_single_file_force_py36(self) -> None:
         reg_mode = DEFAULT_MODE
 
     def test_single_file_force_py36(self) -> None:
         reg_mode = DEFAULT_MODE

-        py36_mode = replace(DEFAULT_MODE, target_versions=black.PY36_VERSIONS)
+        py36_mode = replace(DEFAULT_MODE, target_versions=PY36_VERSIONS)

         source, expected = read_data("force_py36")
         with cache_dir() as workspace:
             path = (workspace / "file.py").resolve()
         source, expected = read_data("force_py36")
         with cache_dir() as workspace:
             path = (workspace / "file.py").resolve()


@@ -1646,7 +1263,7 @@ class BlackTestCase(unittest.TestCase):
     @event_loop()
     def test_multi_file_force_py36(self) -> None:
         reg_mode = DEFAULT_MODE
     @event_loop()
     def test_multi_file_force_py36(self) -> None:
         reg_mode = DEFAULT_MODE

-        py36_mode = replace(DEFAULT_MODE, target_versions=black.PY36_VERSIONS)
+        py36_mode = replace(DEFAULT_MODE, target_versions=PY36_VERSIONS)

         source, expected = read_data("force_py36")
         with cache_dir() as workspace:
             paths = [
         source, expected = read_data("force_py36")
         with cache_dir() as workspace:
             paths = [


@@ -1668,13 +1285,6 @@ class BlackTestCase(unittest.TestCase):
                 self.assertIn(path, pyi_cache)
                 self.assertNotIn(path, normal_cache)
 
                 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(
     def test_pipe_force_py36(self) -> None:
         source, expected = read_data("force_py36")
         result = CliRunner().invoke(


@@ -1726,10 +1336,169 @@ class BlackTestCase(unittest.TestCase):
                 exclude=exclude,
                 force_exclude=None,
                 report=report,
                 exclude=exclude,
                 force_exclude=None,
                 report=report,

+                stdin_filename=None,

             )
         )
         self.assertEqual(sorted(expected), sorted(sources))
 
             )
         )
         self.assertEqual(sorted(expected), sorted(sources))
 

+    @patch("black.find_project_root", lambda *args: THIS_DIR.resolve())
+    def test_get_sources_with_stdin(self) -> None:
+        include = ""
+        exclude = r"/exclude/|a\.py"
+        src = "-"
+        report = black.Report()
+        expected = [Path("-")]
+        sources = list(
+            black.get_sources(
+                ctx=FakeContext(),
+                src=(src,),
+                quiet=True,
+                verbose=False,
+                include=include,
+                exclude=exclude,
+                force_exclude=None,
+                report=report,
+                stdin_filename=None,
+            )
+        )
+        self.assertEqual(sorted(expected), sorted(sources))
+
+    @patch("black.find_project_root", lambda *args: THIS_DIR.resolve())
+    def test_get_sources_with_stdin_filename(self) -> None:
+        include = ""
+        exclude = r"/exclude/|a\.py"
+        src = "-"
+        report = black.Report()
+        stdin_filename = str(THIS_DIR / "data/collections.py")
+        expected = [Path(f"__BLACK_STDIN_FILENAME__{stdin_filename}")]
+        sources = list(
+            black.get_sources(
+                ctx=FakeContext(),
+                src=(src,),
+                quiet=True,
+                verbose=False,
+                include=include,
+                exclude=exclude,
+                force_exclude=None,
+                report=report,
+                stdin_filename=stdin_filename,
+            )
+        )
+        self.assertEqual(sorted(expected), sorted(sources))
+
+    @patch("black.find_project_root", lambda *args: THIS_DIR.resolve())
+    def test_get_sources_with_stdin_filename_and_exclude(self) -> None:
+        # Exclude shouldn't exclude stdin_filename since it is mimicing the
+        # file being passed directly. This is the same as
+        # test_exclude_for_issue_1572
+        path = THIS_DIR / "data" / "include_exclude_tests"
+        include = ""
+        exclude = r"/exclude/|a\.py"
+        src = "-"
+        report = black.Report()
+        stdin_filename = str(path / "b/exclude/a.py")
+        expected = [Path(f"__BLACK_STDIN_FILENAME__{stdin_filename}")]
+        sources = list(
+            black.get_sources(
+                ctx=FakeContext(),
+                src=(src,),
+                quiet=True,
+                verbose=False,
+                include=include,
+                exclude=exclude,
+                force_exclude=None,
+                report=report,
+                stdin_filename=stdin_filename,
+            )
+        )
+        self.assertEqual(sorted(expected), sorted(sources))
+
+    @patch("black.find_project_root", lambda *args: THIS_DIR.resolve())
+    def test_get_sources_with_stdin_filename_and_force_exclude(self) -> None:
+        # Force exclude should exclude the file when passing it through
+        # stdin_filename
+        path = THIS_DIR / "data" / "include_exclude_tests"
+        include = ""
+        force_exclude = r"/exclude/|a\.py"
+        src = "-"
+        report = black.Report()
+        stdin_filename = str(path / "b/exclude/a.py")
+        sources = list(
+            black.get_sources(
+                ctx=FakeContext(),
+                src=(src,),
+                quiet=True,
+                verbose=False,
+                include=include,
+                exclude="",
+                force_exclude=force_exclude,
+                report=report,
+                stdin_filename=stdin_filename,
+            )
+        )
+        self.assertEqual([], sorted(sources))
+
+    def test_reformat_one_with_stdin(self) -> None:
+        with patch(
+            "black.format_stdin_to_stdout",
+            return_value=lambda *args, **kwargs: black.Changed.YES,
+        ) as fsts:
+            report = MagicMock()
+            path = Path("-")
+            black.reformat_one(
+                path,
+                fast=True,
+                write_back=black.WriteBack.YES,
+                mode=DEFAULT_MODE,
+                report=report,
+            )
+            fsts.assert_called_once()
+            report.done.assert_called_with(path, black.Changed.YES)
+
+    def test_reformat_one_with_stdin_filename(self) -> None:
+        with patch(
+            "black.format_stdin_to_stdout",
+            return_value=lambda *args, **kwargs: black.Changed.YES,
+        ) as fsts:
+            report = MagicMock()
+            p = "foo.py"
+            path = Path(f"__BLACK_STDIN_FILENAME__{p}")
+            expected = Path(p)
+            black.reformat_one(
+                path,
+                fast=True,
+                write_back=black.WriteBack.YES,
+                mode=DEFAULT_MODE,
+                report=report,
+            )
+            fsts.assert_called_once()
+            # __BLACK_STDIN_FILENAME__ should have been striped
+            report.done.assert_called_with(expected, black.Changed.YES)
+
+    def test_reformat_one_with_stdin_and_existing_path(self) -> None:
+        with patch(
+            "black.format_stdin_to_stdout",
+            return_value=lambda *args, **kwargs: black.Changed.YES,
+        ) as fsts:
+            report = MagicMock()
+            # Even with an existing file, since we are forcing stdin, black
+            # should output to stdout and not modify the file inplace
+            p = Path(str(THIS_DIR / "data/collections.py"))
+            # Make sure is_file actually returns True
+            self.assertTrue(p.is_file())
+            path = Path(f"__BLACK_STDIN_FILENAME__{p}")
+            expected = Path(p)
+            black.reformat_one(
+                path,
+                fast=True,
+                write_back=black.WriteBack.YES,
+                mode=DEFAULT_MODE,
+                report=report,
+            )
+            fsts.assert_called_once()
+            # __BLACK_STDIN_FILENAME__ should have been striped
+            report.done.assert_called_with(expected, black.Changed.YES)
+

     def test_gitignore_exclude(self) -> None:
         path = THIS_DIR / "data" / "include_exclude_tests"
         include = re.compile(r"\.pyi?$")
     def test_gitignore_exclude(self) -> None:
         path = THIS_DIR / "data" / "include_exclude_tests"
         include = re.compile(r"\.pyi?$")


@@ -1921,14 +1690,6 @@ class BlackTestCase(unittest.TestCase):
         ):
             ff(THIS_FILE)
 
         ):
             ff(THIS_FILE)
 

-    @unittest.skipUnless(has_blackd_deps, "blackd's dependencies are not installed")
-    def test_blackd_main(self) -> None:
-        with patch("blackd.web.run_app"):
-            result = CliRunner().invoke(blackd.main, [])
-            if result.exception is not None:
-                raise result.exception
-            self.assertEqual(result.exit_code, 0)
-

     def test_invalid_config_return_code(self) -> None:
         tmp_file = Path(black.dump_to_file())
         try:
     def test_invalid_config_return_code(self) -> None:
         tmp_file = Path(black.dump_to_file())
         try:


@@ -2005,174 +1766,6 @@ class BlackTestCase(unittest.TestCase):
             os.chdir(str(old_cwd))
 
 
             os.chdir(str(old_cwd))
 
 

-class BlackDTestCase(AioHTTPTestCase):
-    async def get_application(self) -> web.Application:
-        return blackd.make_app()
-
-    # TODO: remove these decorators once the below is released
-    # https://github.com/aio-libs/aiohttp/pull/3727
-    @skip_if_exception("ClientOSError")
-    @unittest.skipUnless(has_blackd_deps, "blackd's dependencies are not installed")
-    @unittest_run_loop
-    async def test_blackd_request_needs_formatting(self) -> None:
-        response = await self.client.post("/", data=b"print('hello world')")
-        self.assertEqual(response.status, 200)
-        self.assertEqual(response.charset, "utf8")
-        self.assertEqual(await response.read(), b'print("hello world")\n')
-
-    @skip_if_exception("ClientOSError")
-    @unittest.skipUnless(has_blackd_deps, "blackd's dependencies are not installed")
-    @unittest_run_loop
-    async def test_blackd_request_no_change(self) -> None:
-        response = await self.client.post("/", data=b'print("hello world")\n')
-        self.assertEqual(response.status, 204)
-        self.assertEqual(await response.read(), b"")
-
-    @skip_if_exception("ClientOSError")
-    @unittest.skipUnless(has_blackd_deps, "blackd's dependencies are not installed")
-    @unittest_run_loop
-    async def test_blackd_request_syntax_error(self) -> None:
-        response = await self.client.post("/", data=b"what even ( is")
-        self.assertEqual(response.status, 400)
-        content = await response.text()
-        self.assertTrue(
-            content.startswith("Cannot parse"),
-            msg=f"Expected error to start with 'Cannot parse', got {repr(content)}",
-        )
-
-    @skip_if_exception("ClientOSError")
-    @unittest.skipUnless(has_blackd_deps, "blackd's dependencies are not installed")
-    @unittest_run_loop
-    async def test_blackd_unsupported_version(self) -> None:
-        response = await self.client.post(
-            "/", data=b"what", headers={blackd.PROTOCOL_VERSION_HEADER: "2"}
-        )
-        self.assertEqual(response.status, 501)
-
-    @skip_if_exception("ClientOSError")
-    @unittest.skipUnless(has_blackd_deps, "blackd's dependencies are not installed")
-    @unittest_run_loop
-    async def test_blackd_supported_version(self) -> None:
-        response = await self.client.post(
-            "/", data=b"what", headers={blackd.PROTOCOL_VERSION_HEADER: "1"}
-        )
-        self.assertEqual(response.status, 200)
-
-    @skip_if_exception("ClientOSError")
-    @unittest.skipUnless(has_blackd_deps, "blackd's dependencies are not installed")
-    @unittest_run_loop
-    async def test_blackd_invalid_python_variant(self) -> None:
-        async def check(header_value: str, expected_status: int = 400) -> None:
-            response = await self.client.post(
-                "/", data=b"what", headers={blackd.PYTHON_VARIANT_HEADER: header_value}
-            )
-            self.assertEqual(response.status, expected_status)
-
-        await check("lol")
-        await check("ruby3.5")
-        await check("pyi3.6")
-        await check("py1.5")
-        await check("2.8")
-        await check("py2.8")
-        await check("3.0")
-        await check("pypy3.0")
-        await check("jython3.4")
-
-    @skip_if_exception("ClientOSError")
-    @unittest.skipUnless(has_blackd_deps, "blackd's dependencies are not installed")
-    @unittest_run_loop
-    async def test_blackd_pyi(self) -> None:
-        source, expected = read_data("stub.pyi")
-        response = await self.client.post(
-            "/", data=source, headers={blackd.PYTHON_VARIANT_HEADER: "pyi"}
-        )
-        self.assertEqual(response.status, 200)
-        self.assertEqual(await response.text(), expected)
-
-    @skip_if_exception("ClientOSError")
-    @unittest.skipUnless(has_blackd_deps, "blackd's dependencies are not installed")
-    @unittest_run_loop
-    async def test_blackd_diff(self) -> None:
-        diff_header = re.compile(
-            r"(In|Out)\t\d\d\d\d-\d\d-\d\d \d\d:\d\d:\d\d\.\d\d\d\d\d\d \+\d\d\d\d"
-        )
-
-        source, _ = read_data("blackd_diff.py")
-        expected, _ = read_data("blackd_diff.diff")
-
-        response = await self.client.post(
-            "/", data=source, headers={blackd.DIFF_HEADER: "true"}
-        )
-        self.assertEqual(response.status, 200)
-
-        actual = await response.text()
-        actual = diff_header.sub(DETERMINISTIC_HEADER, actual)
-        self.assertEqual(actual, expected)
-
-    @skip_if_exception("ClientOSError")
-    @unittest.skipUnless(has_blackd_deps, "blackd's dependencies are not installed")
-    @unittest_run_loop
-    async def test_blackd_python_variant(self) -> None:
-        code = (
-            "def f(\n"
-            "    and_has_a_bunch_of,\n"
-            "    very_long_arguments_too,\n"
-            "    and_lots_of_them_as_well_lol,\n"
-            "    **and_very_long_keyword_arguments\n"
-            "):\n"
-            "    pass\n"
-        )
-
-        async def check(header_value: str, expected_status: int) -> None:
-            response = await self.client.post(
-                "/", data=code, headers={blackd.PYTHON_VARIANT_HEADER: header_value}
-            )
-            self.assertEqual(
-                response.status, expected_status, msg=await response.text()
-            )
-
-        await check("3.6", 200)
-        await check("py3.6", 200)
-        await check("3.6,3.7", 200)
-        await check("3.6,py3.7", 200)
-        await check("py36,py37", 200)
-        await check("36", 200)
-        await check("3.6.4", 200)
-
-        await check("2", 204)
-        await check("2.7", 204)
-        await check("py2.7", 204)
-        await check("3.4", 204)
-        await check("py3.4", 204)
-        await check("py34,py36", 204)
-        await check("34", 204)
-
-    @skip_if_exception("ClientOSError")
-    @unittest.skipUnless(has_blackd_deps, "blackd's dependencies are not installed")
-    @unittest_run_loop
-    async def test_blackd_line_length(self) -> None:
-        response = await self.client.post(
-            "/", data=b'print("hello")\n', headers={blackd.LINE_LENGTH_HEADER: "7"}
-        )
-        self.assertEqual(response.status, 200)
-
-    @skip_if_exception("ClientOSError")
-    @unittest.skipUnless(has_blackd_deps, "blackd's dependencies are not installed")
-    @unittest_run_loop
-    async def test_blackd_invalid_line_length(self) -> None:
-        response = await self.client.post(
-            "/", data=b'print("hello")\n', headers={blackd.LINE_LENGTH_HEADER: "NaN"}
-        )
-        self.assertEqual(response.status, 400)
-
-    @skip_if_exception("ClientOSError")
-    @unittest.skipUnless(has_blackd_deps, "blackd's dependencies are not installed")
-    @unittest_run_loop
-    async def test_blackd_response_black_version_header(self) -> None:
-        response = await self.client.post("/")
-        self.assertIsNotNone(response.headers.get(blackd.BLACK_VERSION_HEADER))
-
-

 with open(black.__file__, "r", encoding="utf-8") as _bf:
     black_source_lines = _bf.readlines()
 
 with open(black.__file__, "r", encoding="utf-8") as _bf:
     black_source_lines = _bf.readlines()