]> git.madduck.net Git - etc/vim.git/blobdiff - tests/test_black.py

madduck's git repository

Every one of the projects in this repository is available at the canonical URL git://git.madduck.net/madduck/pub/<projectpath> — see each project's metadata for the exact URL.

All patches and comments are welcome. Please squash your changes to logical commits before using git-format-patch and git-send-email to patches@git.madduck.net. If you'd read over the Git project's submission guidelines and adhered to them, I'd be especially grateful.

SSH access, as well as push access can be individually arranged.

If you use my repositories frequently, consider adding the following snippet to ~/.gitconfig and using the third clone URL listed for each project:

[url "git://git.madduck.net/madduck/"]
  insteadOf = madduck:

Declare support for Python 3.8 (#1069)
[etc/vim.git] / tests / test_black.py
index 5532fc563d328d18cf012770e2d38f7567bf3b45..10efbcf214f7eff96921a48ae74662c89c5eec72 100644 (file)
@@ -1,25 +1,16 @@
 #!/usr/bin/env python3
 import asyncio
+import logging
 from concurrent.futures import ThreadPoolExecutor
-from contextlib import contextmanager, redirect_stderr
-from functools import partial, wraps
+from contextlib import contextmanager
+from functools import partial
 from io import BytesIO, TextIOWrapper
 import os
 from pathlib import Path
-import re
+import regex as re
 import sys
 from tempfile import TemporaryDirectory
-from typing import (
-    Any,
-    BinaryIO,
-    Callable,
-    Coroutine,
-    Generator,
-    List,
-    Tuple,
-    Iterator,
-    TypeVar,
-)
+from typing import Any, BinaryIO, Generator, List, Tuple, Iterator, TypeVar
 import unittest
 from unittest.mock import patch, MagicMock
 
@@ -27,22 +18,25 @@ from click import unstyle
 from click.testing import CliRunner
 
 import black
-from black import Feature
+from black import Feature, TargetVersion
 
 try:
     import blackd
-    from aiohttp.test_utils import TestClient, TestServer
+    from aiohttp.test_utils import AioHTTPTestCase, unittest_run_loop
+    from aiohttp import web
 except ImportError:
     has_blackd_deps = False
 else:
     has_blackd_deps = True
 
-
 ff = partial(black.format_file_in_place, mode=black.FileMode(), fast=True)
 fs = partial(black.format_str, mode=black.FileMode())
 THIS_FILE = Path(__file__)
 THIS_DIR = THIS_FILE.parent
 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
+]
 T = TypeVar("T")
 R = TypeVar("R")
 
@@ -87,25 +81,25 @@ def cache_dir(exists: bool = True) -> Iterator[Path]:
 @contextmanager
 def event_loop(close: bool) -> Iterator[None]:
     policy = asyncio.get_event_loop_policy()
-    old_loop = policy.get_event_loop()
     loop = policy.new_event_loop()
     asyncio.set_event_loop(loop)
     try:
         yield
 
     finally:
-        policy.set_event_loop(old_loop)
         if close:
             loop.close()
 
 
-def async_test(f: Callable[..., Coroutine[Any, None, R]]) -> Callable[..., None]:
-    @event_loop(close=True)
-    @wraps(f)
-    def wrapper(*args: Any, **kwargs: Any) -> None:
-        asyncio.get_event_loop().run_until_complete(f(*args, **kwargs))
-
-    return wrapper
+@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 BlackRunner(CliRunner):
@@ -261,6 +255,14 @@ 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, black.FileMode())
+
     @patch("black.dump_to_file", dump_to_stderr)
     def test_expression(self) -> None:
         source, expected = read_data("expression")
@@ -269,6 +271,23 @@ 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_pep_572(self) -> None:
+        source, expected = read_data("pep_572")
+        actual = fs(source)
+        self.assertFormatEqual(expected, actual)
+        black.assert_stable(source, actual, black.FileMode())
+        if sys.version_info >= (3, 8):
+            black.assert_equivalent(source, actual)
+
+    def test_pep_572_version_detection(self) -> None:
+        source, _ = read_data("pep_572")
+        root = black.lib2to3_parse(source)
+        features = black.get_features_used(root)
+        self.assertIn(black.Feature.ASSIGNMENT_EXPRESSIONS, features)
+        versions = black.detect_target_versions(root)
+        self.assertIn(black.TargetVersion.PY38, versions)
+
     def test_expression_ff(self) -> None:
         source, expected = read_data("expression")
         tmp_file = Path(black.dump_to_file(source))
@@ -316,6 +335,23 @@ 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_pep_570(self) -> None:
+        source, expected = read_data("pep_570")
+        actual = fs(source)
+        self.assertFormatEqual(expected, actual)
+        black.assert_stable(source, actual, black.FileMode())
+        if sys.version_info >= (3, 8):
+            black.assert_equivalent(source, actual)
+
+    def test_detect_pos_only_arguments(self) -> None:
+        source, _ = read_data("pep_570")
+        root = black.lib2to3_parse(source)
+        features = black.get_features_used(root)
+        self.assertIn(black.Feature.POS_ONLY_ARGUMENTS, features)
+        versions = black.detect_target_versions(root)
+        self.assertIn(black.TargetVersion.PY38, versions)
+
     @patch("black.dump_to_file", dump_to_stderr)
     def test_string_quotes(self) -> None:
         source, expected = read_data("string_quotes")
@@ -385,6 +421,22 @@ 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_comments7(self) -> None:
+        source, expected = read_data("comments7")
+        actual = fs(source)
+        self.assertFormatEqual(expected, actual)
+        black.assert_equivalent(source, actual)
+        black.assert_stable(source, actual, black.FileMode())
+
+    @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, black.FileMode())
+
     @patch("black.dump_to_file", dump_to_stderr)
     def test_cantfit(self) -> None:
         source, expected = read_data("cantfit")
@@ -417,6 +469,14 @@ 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_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, black.FileMode())
+
     @patch("black.dump_to_file", dump_to_stderr)
     def test_string_prefixes(self) -> None:
         source, expected = read_data("string_prefixes")
@@ -437,9 +497,7 @@ 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")
-        mode = black.FileMode(
-            numeric_underscore_normalization=False, target_versions=black.PY36_VERSIONS
-        )
+        mode = black.FileMode(target_versions=black.PY36_VERSIONS)
         actual = fs(source, mode=mode)
         self.assertFormatEqual(expected, actual)
         black.assert_equivalent(source, actual)
@@ -457,14 +515,24 @@ class BlackTestCase(unittest.TestCase):
         source, expected = read_data("python2")
         actual = fs(source)
         self.assertFormatEqual(expected, actual)
-        black.assert_equivalent(source, actual)
+        black.assert_equivalent(source, actual)
         black.assert_stable(source, actual, black.FileMode())
 
+    @patch("black.dump_to_file", dump_to_stderr)
+    def test_python2_print_function(self) -> None:
+        source, expected = read_data("python2_print_function")
+        mode = black.FileMode(target_versions={TargetVersion.PY27})
+        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_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, black.FileMode())
 
     @patch("black.dump_to_file", dump_to_stderr)
@@ -475,8 +543,24 @@ class BlackTestCase(unittest.TestCase):
         self.assertFormatEqual(expected, actual)
         black.assert_stable(source, actual, mode)
 
+    @patch("black.dump_to_file", dump_to_stderr)
+    def test_async_as_identifier(self) -> None:
+        source_path = (THIS_DIR / "data" / "async_as_identifier.py").resolve()
+        source, expected = read_data("async_as_identifier")
+        actual = fs(source)
+        self.assertFormatEqual(expected, actual)
+        major, minor = sys.version_info[:2]
+        if major < 3 or (major <= 3 and minor < 7):
+            black.assert_equivalent(source, actual)
+        black.assert_stable(source, actual, black.FileMode())
+        # ensure black can parse this when the target is 3.6
+        self.invokeBlack([str(source_path), "--target-version", "py36"])
+        # but not on 3.7, because async/await is no longer an identifier
+        self.invokeBlack([str(source_path), "--target-version", "py37"], exit_code=123)
+
     @patch("black.dump_to_file", dump_to_stderr)
     def test_python37(self) -> None:
+        source_path = (THIS_DIR / "data" / "python37.py").resolve()
         source, expected = read_data("python37")
         actual = fs(source)
         self.assertFormatEqual(expected, actual)
@@ -484,6 +568,10 @@ class BlackTestCase(unittest.TestCase):
         if major > 3 or (major == 3 and minor >= 7):
             black.assert_equivalent(source, actual)
         black.assert_stable(source, actual, black.FileMode())
+        # ensure black can parse this when the target is 3.7
+        self.invokeBlack([str(source_path), "--target-version", "py37"])
+        # but not on 3.6, because we use async as a reserved keyword
+        self.invokeBlack([str(source_path), "--target-version", "py36"], exit_code=123)
 
     @patch("black.dump_to_file", dump_to_stderr)
     def test_fmtonoff(self) -> None:
@@ -525,18 +613,43 @@ class BlackTestCase(unittest.TestCase):
         black.assert_equivalent(source, actual)
         black.assert_stable(source, actual, black.FileMode())
 
-    def test_comment_indentation(self) -> None:
+    @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, black.FileMode())
+
+    @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, black.FileMode())
+
+    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"
-
-        self.assertFormatEqual(fs(contents_spc), contents_spc)
-        self.assertFormatEqual(fs(contents_tab), contents_spc)
+        self.assertFormatEqual(contents_spc, fs(contents_spc))
+        self.assertFormatEqual(contents_spc, fs(contents_tab))
 
         contents_tab = "if 1:\n\tif 2:\n\t\tpass\n\t\t# comment\n\tpass\n"
         contents_spc = "if 1:\n    if 2:\n        pass\n        # comment\n    pass\n"
+        self.assertFormatEqual(contents_spc, fs(contents_spc))
+        self.assertFormatEqual(contents_spc, fs(contents_tab))
+
+        # mixed tabs and spaces (valid Python 2 code)
+        contents_tab = "if 1:\n        if 2:\n\t\tpass\n\t# comment\n        pass\n"
+        contents_spc = "if 1:\n    if 2:\n        pass\n    # comment\n    pass\n"
+        self.assertFormatEqual(contents_spc, fs(contents_spc))
+        self.assertFormatEqual(contents_spc, fs(contents_tab))
 
-        self.assertFormatEqual(fs(contents_tab), contents_spc)
-        self.assertFormatEqual(fs(contents_spc), contents_spc)
+        contents_tab = "if 1:\n        if 2:\n\t\tpass\n\t\t# comment\n        pass\n"
+        contents_spc = "if 1:\n    if 2:\n        pass\n        # comment\n    pass\n"
+        self.assertFormatEqual(contents_spc, fs(contents_spc))
+        self.assertFormatEqual(contents_spc, fs(contents_tab))
 
     def test_report_verbose(self) -> None:
         report = black.Report(verbose=True)
@@ -810,11 +923,40 @@ class BlackTestCase(unittest.TestCase):
                 "2 files would fail to reformat.",
             )
 
+    def test_lib2to3_parse(self) -> None:
+        with self.assertRaises(black.InvalidInput):
+            black.lib2to3_parse("invalid syntax")
+
+        straddling = "x + y"
+        black.lib2to3_parse(straddling)
+        black.lib2to3_parse(straddling, {TargetVersion.PY27})
+        black.lib2to3_parse(straddling, {TargetVersion.PY36})
+        black.lib2to3_parse(straddling, {TargetVersion.PY27, TargetVersion.PY36})
+
+        py2_only = "print x"
+        black.lib2to3_parse(py2_only)
+        black.lib2to3_parse(py2_only, {TargetVersion.PY27})
+        with self.assertRaises(black.InvalidInput):
+            black.lib2to3_parse(py2_only, {TargetVersion.PY36})
+        with self.assertRaises(black.InvalidInput):
+            black.lib2to3_parse(py2_only, {TargetVersion.PY27, TargetVersion.PY36})
+
+        py3_only = "exec(x, end=y)"
+        black.lib2to3_parse(py3_only)
+        with self.assertRaises(black.InvalidInput):
+            black.lib2to3_parse(py3_only, {TargetVersion.PY27})
+        black.lib2to3_parse(py3_only, {TargetVersion.PY36})
+        black.lib2to3_parse(py3_only, {TargetVersion.PY27, TargetVersion.PY36})
+
     def test_get_features_used(self) -> None:
         node = black.lib2to3_parse("def f(*, arg): ...\n")
         self.assertEqual(black.get_features_used(node), set())
         node = black.lib2to3_parse("def f(*, arg,): ...\n")
-        self.assertEqual(black.get_features_used(node), {Feature.TRAILING_COMMA})
+        self.assertEqual(black.get_features_used(node), {Feature.TRAILING_COMMA_IN_DEF})
+        node = black.lib2to3_parse("f(*arg,)\n")
+        self.assertEqual(
+            black.get_features_used(node), {Feature.TRAILING_COMMA_IN_CALL}
+        )
         node = black.lib2to3_parse("def f(*, arg): f'string'\n")
         self.assertEqual(black.get_features_used(node), {Feature.F_STRINGS})
         node = black.lib2to3_parse("123_456\n")
@@ -823,14 +965,14 @@ class BlackTestCase(unittest.TestCase):
         self.assertEqual(black.get_features_used(node), set())
         source, expected = read_data("function")
         node = black.lib2to3_parse(source)
-        self.assertEqual(
-            black.get_features_used(node), {Feature.TRAILING_COMMA, Feature.F_STRINGS}
-        )
+        expected_features = {
+            Feature.TRAILING_COMMA_IN_CALL,
+            Feature.TRAILING_COMMA_IN_DEF,
+            Feature.F_STRINGS,
+        }
+        self.assertEqual(black.get_features_used(node), expected_features)
         node = black.lib2to3_parse(expected)
-        self.assertEqual(
-            black.get_features_used(node),
-            {Feature.TRAILING_COMMA, Feature.F_STRINGS, Feature.NUMERIC_UNDERSCORES},
-        )
+        self.assertEqual(black.get_features_used(node), expected_features)
         source, expected = read_data("expression")
         node = black.lib2to3_parse(source)
         self.assertEqual(black.get_features_used(node), set())
@@ -899,10 +1041,10 @@ class BlackTestCase(unittest.TestCase):
         just_nl = "\n"
         with self.assertRaises(black.NothingChanged):
             black.format_file_contents(just_nl, mode=mode, fast=False)
-        same = "l = [1, 2, 3]\n"
+        same = "j = [1, 2, 3]\n"
         with self.assertRaises(black.NothingChanged):
             black.format_file_contents(same, mode=mode, fast=False)
-        different = "l = [1,2,3]"
+        different = "j = [1,2,3]"
         expected = same
         actual = black.format_file_contents(different, mode=mode, fast=False)
         self.assertEqual(expected, actual)
@@ -930,7 +1072,7 @@ class BlackTestCase(unittest.TestCase):
 
         with patch("black.out", out), patch("black.err", err):
             with self.assertRaises(AssertionError):
-                self.assertFormatEqual("l = [1, 2, 3]", "l = [1, 2, 3,]")
+                self.assertFormatEqual("j = [1, 2, 3]", "j = [1, 2, 3,]")
 
         out_str = "".join(out_lines)
         self.assertTrue("Expected tree:" in out_str)
@@ -1103,6 +1245,13 @@ 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, black.FileMode())
+
     def test_single_file_force_pyi(self) -> None:
         reg_mode = black.FileMode()
         pyi_mode = black.FileMode(is_pyi=True)
@@ -1163,10 +1312,10 @@ class BlackTestCase(unittest.TestCase):
             path = (workspace / "file.py").resolve()
             with open(path, "w") as fh:
                 fh.write(source)
-            self.invokeBlack([str(path), "--py36"])
+            self.invokeBlack([str(path), *PY36_ARGS])
             with open(path, "r") as fh:
                 actual = fh.read()
-            # verify cache with --py36 is separate
+            # verify cache with --target-version is separate
             py36_cache = black.read_cache(py36_mode)
             self.assertIn(path, py36_cache)
             normal_cache = black.read_cache(reg_mode)
@@ -1186,12 +1335,12 @@ class BlackTestCase(unittest.TestCase):
             for path in paths:
                 with open(path, "w") as fh:
                     fh.write(source)
-            self.invokeBlack([str(p) for p in paths] + ["--py36"])
+            self.invokeBlack([str(p) for p in paths] + PY36_ARGS)
             for path in paths:
                 with open(path, "r") as fh:
                     actual = fh.read()
                 self.assertEqual(actual, expected)
-            # verify cache with --py36 is separate
+            # verify cache with --target-version is separate
             pyi_cache = black.read_cache(py36_mode)
             normal_cache = black.read_cache(reg_mode)
             for path in paths:
@@ -1201,7 +1350,9 @@ class BlackTestCase(unittest.TestCase):
     def test_pipe_force_py36(self) -> None:
         source, expected = read_data("force_py36")
         result = CliRunner().invoke(
-            black.main, ["-", "-q", "--py36"], input=BytesIO(source.encode("utf8"))
+            black.main,
+            ["-", "-q", "--target-version=py36"],
+            input=BytesIO(source.encode("utf8")),
         )
         self.assertEqual(result.exit_code, 0)
         actual = result.output
@@ -1354,98 +1505,118 @@ class BlackTestCase(unittest.TestCase):
             except RuntimeError as re:
                 self.fail(f"`patch_click()` failed, exception still raised: {re}")
 
+    def test_root_logger_not_used_directly(self) -> None:
+        def fail(*args: Any, **kwargs: Any) -> None:
+            self.fail("Record created with root logger")
+
+        with patch.multiple(
+            logging.root,
+            debug=fail,
+            info=fail,
+            warning=fail,
+            error=fail,
+            critical=fail,
+            log=fail,
+        ):
+            ff(THIS_FILE)
+
     @unittest.skipUnless(has_blackd_deps, "blackd's dependencies are not installed")
-    @async_test
+    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)
+
+
+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:
-        app = blackd.make_app()
-        async with TestClient(TestServer(app)) as client:
-            response = await 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')
+        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")
-    @async_test
+    @unittest_run_loop
     async def test_blackd_request_no_change(self) -> None:
-        app = blackd.make_app()
-        async with TestClient(TestServer(app)) as client:
-            response = await client.post("/", data=b'print("hello world")\n')
-            self.assertEqual(response.status, 204)
-            self.assertEqual(await response.read(), b"")
+        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")
-    @async_test
+    @unittest_run_loop
     async def test_blackd_request_syntax_error(self) -> None:
-        app = blackd.make_app()
-        async with TestClient(TestServer(app)) as client:
-            response = await 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)}",
-            )
+        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")
-    @async_test
+    @unittest_run_loop
     async def test_blackd_unsupported_version(self) -> None:
-        app = blackd.make_app()
-        async with TestClient(TestServer(app)) as client:
-            response = await client.post(
-                "/", data=b"what", headers={blackd.VERSION_HEADER: "2"}
-            )
-            self.assertEqual(response.status, 501)
+        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")
-    @async_test
+    @unittest_run_loop
     async def test_blackd_supported_version(self) -> None:
-        app = blackd.make_app()
-        async with TestClient(TestServer(app)) as client:
-            response = await client.post(
-                "/", data=b"what", headers={blackd.VERSION_HEADER: "1"}
-            )
-            self.assertEqual(response.status, 200)
+        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")
-    @async_test
+    @unittest_run_loop
     async def test_blackd_invalid_python_variant(self) -> None:
-        app = blackd.make_app()
-        async with TestClient(TestServer(app)) as client:
-
-            async def check(header_value: str, expected_status: int = 400) -> None:
-                response = await 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("cpy1.5")
-            await check("2.8")
-            await check("cpy2.8")
-            await check("3.0")
-            await check("pypy3.0")
-            await check("jython3.4")
-
+        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")
-    @async_test
+    @unittest_run_loop
     async def test_blackd_pyi(self) -> None:
-        app = blackd.make_app()
-        async with TestClient(TestServer(app)) as client:
-            source, expected = read_data("stub.pyi")
-            response = await client.post(
-                "/", data=source, headers={blackd.PYTHON_VARIANT_HEADER: "pyi"}
-            )
-            self.assertEqual(response.status, 200)
-            self.assertEqual(await response.text(), expected)
+        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")
-    @async_test
+    @unittest_run_loop
     async def test_blackd_python_variant(self) -> None:
-        app = blackd.make_app()
         code = (
             "def f(\n"
             "    and_has_a_bunch_of,\n"
@@ -1455,70 +1626,55 @@ class BlackTestCase(unittest.TestCase):
             "):\n"
             "    pass\n"
         )
-        async with TestClient(TestServer(app)) as client:
-
-            async def check(header_value: str, expected_status: int) -> None:
-                response = await client.post(
-                    "/", data=code, headers={blackd.PYTHON_VARIANT_HEADER: header_value}
-                )
-                self.assertEqual(response.status, expected_status)
-
-            await check("3.6", 200)
-            await check("cpy3.6", 200)
-            await check("3.5,3.7", 200)
-            await check("3.5,cpy3.7", 200)
-
-            await check("2", 204)
-            await check("2.7", 204)
-            await check("cpy2.7", 204)
-            await check("pypy2.7", 204)
-            await check("3.4", 204)
-            await check("cpy3.4", 204)
-            await check("pypy3.4", 204)
 
-    @unittest.skipUnless(has_blackd_deps, "blackd's dependencies are not installed")
-    @async_test
-    async def test_blackd_fast(self) -> None:
-        with open(os.devnull, "w") as dn, redirect_stderr(dn):
-            app = blackd.make_app()
-            async with TestClient(TestServer(app)) as client:
-                response = await client.post("/", data=b"ur'hello'")
-                self.assertEqual(response.status, 500)
-                self.assertIn("failed to parse source file", await response.text())
-                response = await client.post(
-                    "/", data=b"ur'hello'", headers={blackd.FAST_OR_SAFE_HEADER: "fast"}
-                )
-                self.assertEqual(response.status, 200)
+        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")
-    @async_test
+    @unittest_run_loop
     async def test_blackd_line_length(self) -> None:
-        app = blackd.make_app()
-        async with TestClient(TestServer(app)) as client:
-            response = await client.post(
-                "/", data=b'print("hello")\n', headers={blackd.LINE_LENGTH_HEADER: "7"}
-            )
-            self.assertEqual(response.status, 200)
+        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")
-    @async_test
+    @unittest_run_loop
     async def test_blackd_invalid_line_length(self) -> None:
-        app = blackd.make_app()
-        async with TestClient(TestServer(app)) as client:
-            response = await client.post(
-                "/",
-                data=b'print("hello")\n',
-                headers={blackd.LINE_LENGTH_HEADER: "NaN"},
-            )
-            self.assertEqual(response.status, 400)
+        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")
-    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)
+    @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))
 
 
 if __name__ == "__main__":