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Bump peter-evans/find-comment from 2.0.1 to 2.1.0 (#3404)
[etc/vim.git] / tests / test_black.py
index b04c0a66fe9e4120c69121c8fd7dbbf033dec4dd..dda10555c970e3ebcb305bb454dc43d755313e3c 100644 (file)
@@ -6,11 +6,12 @@ import io
 import logging
 import multiprocessing
 import os
 import logging
 import multiprocessing
 import os
+import re
 import sys
 import types
 import unittest
 from concurrent.futures import ThreadPoolExecutor
 import sys
 import types
 import unittest
 from concurrent.futures import ThreadPoolExecutor
-from contextlib import contextmanager
+from contextlib import contextmanager, redirect_stderr
 from dataclasses import replace
 from io import BytesIO
 from pathlib import Path
 from dataclasses import replace
 from io import BytesIO
 from pathlib import Path
@@ -24,6 +25,7 @@ from typing import (
     List,
     Optional,
     Sequence,
     List,
     Optional,
     Sequence,
+    Type,
     TypeVar,
     Union,
 )
     TypeVar,
     Union,
 )
@@ -31,7 +33,6 @@ from unittest.mock import MagicMock, patch
 
 import click
 import pytest
 
 import click
 import pytest
-import re
 from click import unstyle
 from click.testing import CliRunner
 from pathspec import PathSpec
 from click import unstyle
 from click.testing import CliRunner
 from pathspec import PathSpec
@@ -59,10 +60,13 @@ from tests.util import (
     dump_to_stderr,
     ff,
     fs,
     dump_to_stderr,
     ff,
     fs,
+    get_case_path,
     read_data,
     read_data,
+    read_data_from_file,
 )
 
 THIS_FILE = Path(__file__)
 )
 
 THIS_FILE = Path(__file__)
+EMPTY_CONFIG = THIS_DIR / "data" / "empty_pyproject.toml"
 PY36_ARGS = [f"--target-version={version.name.lower()}" for version in PY36_VERSIONS]
 DEFAULT_EXCLUDE = black.re_compile_maybe_verbose(black.const.DEFAULT_EXCLUDES)
 DEFAULT_INCLUDE = black.re_compile_maybe_verbose(black.const.DEFAULT_INCLUDES)
 PY36_ARGS = [f"--target-version={version.name.lower()}" for version in PY36_VERSIONS]
 DEFAULT_EXCLUDE = black.re_compile_maybe_verbose(black.const.DEFAULT_EXCLUDES)
 DEFAULT_INCLUDE = black.re_compile_maybe_verbose(black.const.DEFAULT_INCLUDES)
@@ -150,16 +154,49 @@ class BlackTestCase(BlackBaseTestCase):
             os.unlink(tmp_file)
         self.assertFormatEqual(expected, actual)
 
             os.unlink(tmp_file)
         self.assertFormatEqual(expected, actual)
 
+    @patch("black.dump_to_file", dump_to_stderr)
+    def test_one_empty_line(self) -> None:
+        mode = black.Mode(preview=True)
+        for nl in ["\n", "\r\n"]:
+            source = expected = nl
+            assert_format(source, expected, mode=mode)
+
+    def test_one_empty_line_ff(self) -> None:
+        mode = black.Mode(preview=True)
+        for nl in ["\n", "\r\n"]:
+            expected = nl
+            tmp_file = Path(black.dump_to_file(nl))
+            if system() == "Windows":
+                # Writing files in text mode automatically uses the system newline,
+                # but in this case we don't want this for testing reasons. See:
+                # https://github.com/psf/black/pull/3348
+                with open(tmp_file, "wb") as f:
+                    f.write(nl.encode("utf-8"))
+            try:
+                self.assertFalse(
+                    ff(tmp_file, mode=mode, write_back=black.WriteBack.YES)
+                )
+                with open(tmp_file, "rb") as f:
+                    actual = f.read().decode("utf8")
+            finally:
+                os.unlink(tmp_file)
+            self.assertFormatEqual(expected, actual)
+
     def test_experimental_string_processing_warns(self) -> None:
         self.assertWarns(
             black.mode.Deprecated, black.Mode, experimental_string_processing=True
         )
 
     def test_piping(self) -> None:
     def test_experimental_string_processing_warns(self) -> None:
         self.assertWarns(
             black.mode.Deprecated, black.Mode, experimental_string_processing=True
         )
 
     def test_piping(self) -> None:
-        source, expected = read_data("src/black/__init__", data=False)
+        source, expected = read_data_from_file(PROJECT_ROOT / "src/black/__init__.py")
         result = BlackRunner().invoke(
             black.main,
         result = BlackRunner().invoke(
             black.main,
-            ["-", "--fast", f"--line-length={black.DEFAULT_LINE_LENGTH}"],
+            [
+                "-",
+                "--fast",
+                f"--line-length={black.DEFAULT_LINE_LENGTH}",
+                f"--config={EMPTY_CONFIG}",
+            ],
             input=BytesIO(source.encode("utf8")),
         )
         self.assertEqual(result.exit_code, 0)
             input=BytesIO(source.encode("utf8")),
         )
         self.assertEqual(result.exit_code, 0)
@@ -173,15 +210,14 @@ class BlackTestCase(BlackBaseTestCase):
             r"(STDIN|STDOUT)\t\d\d\d\d-\d\d-\d\d \d\d:\d\d:\d\d\.\d\d\d\d\d\d "
             r"\+\d\d\d\d"
         )
             r"(STDIN|STDOUT)\t\d\d\d\d-\d\d-\d\d \d\d:\d\d:\d\d\.\d\d\d\d\d\d "
             r"\+\d\d\d\d"
         )
-        source, _ = read_data("expression.py")
-        expected, _ = read_data("expression.diff")
-        config = THIS_DIR / "data" / "empty_pyproject.toml"
+        source, _ = read_data("simple_cases", "expression.py")
+        expected, _ = read_data("simple_cases", "expression.diff")
         args = [
             "-",
             "--fast",
             f"--line-length={black.DEFAULT_LINE_LENGTH}",
             "--diff",
         args = [
             "-",
             "--fast",
             f"--line-length={black.DEFAULT_LINE_LENGTH}",
             "--diff",
-            f"--config={config}",
+            f"--config={EMPTY_CONFIG}",
         ]
         result = BlackRunner().invoke(
             black.main, args, input=BytesIO(source.encode("utf8"))
         ]
         result = BlackRunner().invoke(
             black.main, args, input=BytesIO(source.encode("utf8"))
@@ -192,15 +228,14 @@ class BlackTestCase(BlackBaseTestCase):
         self.assertEqual(expected, actual)
 
     def test_piping_diff_with_color(self) -> None:
         self.assertEqual(expected, actual)
 
     def test_piping_diff_with_color(self) -> None:
-        source, _ = read_data("expression.py")
-        config = THIS_DIR / "data" / "empty_pyproject.toml"
+        source, _ = read_data("simple_cases", "expression.py")
         args = [
             "-",
             "--fast",
             f"--line-length={black.DEFAULT_LINE_LENGTH}",
             "--diff",
             "--color",
         args = [
             "-",
             "--fast",
             f"--line-length={black.DEFAULT_LINE_LENGTH}",
             "--diff",
             "--color",
-            f"--config={config}",
+            f"--config={EMPTY_CONFIG}",
         ]
         result = BlackRunner().invoke(
             black.main, args, input=BytesIO(source.encode("utf8"))
         ]
         result = BlackRunner().invoke(
             black.main, args, input=BytesIO(source.encode("utf8"))
@@ -215,7 +250,7 @@ class BlackTestCase(BlackBaseTestCase):
 
     @patch("black.dump_to_file", dump_to_stderr)
     def _test_wip(self) -> None:
 
     @patch("black.dump_to_file", dump_to_stderr)
     def _test_wip(self) -> None:
-        source, expected = read_data("wip")
+        source, expected = read_data("miscellaneous", "wip")
         sys.settrace(tracefunc)
         mode = replace(
             DEFAULT_MODE,
         sys.settrace(tracefunc)
         mode = replace(
             DEFAULT_MODE,
@@ -229,7 +264,7 @@ class BlackTestCase(BlackBaseTestCase):
         black.assert_stable(source, actual, black.FileMode())
 
     def test_pep_572_version_detection(self) -> None:
         black.assert_stable(source, actual, black.FileMode())
 
     def test_pep_572_version_detection(self) -> None:
-        source, _ = read_data("pep_572")
+        source, _ = read_data("py_38", "pep_572")
         root = black.lib2to3_parse(source)
         features = black.get_features_used(root)
         self.assertIn(black.Feature.ASSIGNMENT_EXPRESSIONS, features)
         root = black.lib2to3_parse(source)
         features = black.get_features_used(root)
         self.assertIn(black.Feature.ASSIGNMENT_EXPRESSIONS, features)
@@ -237,7 +272,7 @@ class BlackTestCase(BlackBaseTestCase):
         self.assertIn(black.TargetVersion.PY38, versions)
 
     def test_expression_ff(self) -> None:
         self.assertIn(black.TargetVersion.PY38, versions)
 
     def test_expression_ff(self) -> None:
-        source, expected = read_data("expression")
+        source, expected = read_data("simple_cases", "expression.py")
         tmp_file = Path(black.dump_to_file(source))
         try:
             self.assertTrue(ff(tmp_file, write_back=black.WriteBack.YES))
         tmp_file = Path(black.dump_to_file(source))
         try:
             self.assertTrue(ff(tmp_file, write_back=black.WriteBack.YES))
@@ -251,9 +286,8 @@ class BlackTestCase(BlackBaseTestCase):
             black.assert_stable(source, actual, DEFAULT_MODE)
 
     def test_expression_diff(self) -> None:
             black.assert_stable(source, actual, DEFAULT_MODE)
 
     def test_expression_diff(self) -> None:
-        source, _ = read_data("expression.py")
-        config = THIS_DIR / "data" / "empty_pyproject.toml"
-        expected, _ = read_data("expression.diff")
+        source, _ = read_data("simple_cases", "expression.py")
+        expected, _ = read_data("simple_cases", "expression.diff")
         tmp_file = Path(black.dump_to_file(source))
         diff_header = re.compile(
             rf"{re.escape(str(tmp_file))}\t\d\d\d\d-\d\d-\d\d "
         tmp_file = Path(black.dump_to_file(source))
         diff_header = re.compile(
             rf"{re.escape(str(tmp_file))}\t\d\d\d\d-\d\d-\d\d "
@@ -261,7 +295,7 @@ class BlackTestCase(BlackBaseTestCase):
         )
         try:
             result = BlackRunner().invoke(
         )
         try:
             result = BlackRunner().invoke(
-                black.main, ["--diff", str(tmp_file), f"--config={config}"]
+                black.main, ["--diff", str(tmp_file), f"--config={EMPTY_CONFIG}"]
             )
             self.assertEqual(result.exit_code, 0)
         finally:
             )
             self.assertEqual(result.exit_code, 0)
         finally:
@@ -278,13 +312,13 @@ class BlackTestCase(BlackBaseTestCase):
             self.assertEqual(expected, actual, msg)
 
     def test_expression_diff_with_color(self) -> None:
             self.assertEqual(expected, actual, msg)
 
     def test_expression_diff_with_color(self) -> None:
-        source, _ = read_data("expression.py")
-        config = THIS_DIR / "data" / "empty_pyproject.toml"
-        expected, _ = read_data("expression.diff")
+        source, _ = read_data("simple_cases", "expression.py")
+        expected, _ = read_data("simple_cases", "expression.diff")
         tmp_file = Path(black.dump_to_file(source))
         try:
             result = BlackRunner().invoke(
         tmp_file = Path(black.dump_to_file(source))
         try:
             result = BlackRunner().invoke(
-                black.main, ["--diff", "--color", str(tmp_file), f"--config={config}"]
+                black.main,
+                ["--diff", "--color", str(tmp_file), f"--config={EMPTY_CONFIG}"],
             )
         finally:
             os.unlink(tmp_file)
             )
         finally:
             os.unlink(tmp_file)
@@ -298,16 +332,36 @@ class BlackTestCase(BlackBaseTestCase):
         self.assertIn("\033[0m", actual)
 
     def test_detect_pos_only_arguments(self) -> None:
         self.assertIn("\033[0m", actual)
 
     def test_detect_pos_only_arguments(self) -> None:
-        source, _ = read_data("pep_570")
+        source, _ = read_data("py_38", "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)
 
         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)
 
+    def test_detect_debug_f_strings(self) -> None:
+        root = black.lib2to3_parse("""f"{x=}" """)
+        features = black.get_features_used(root)
+        self.assertIn(black.Feature.DEBUG_F_STRINGS, features)
+        versions = black.detect_target_versions(root)
+        self.assertIn(black.TargetVersion.PY38, versions)
+
+        root = black.lib2to3_parse(
+            """f"{x}"\nf'{"="}'\nf'{(x:=5)}'\nf'{f(a="3=")}'\nf'{x:=10}'\n"""
+        )
+        features = black.get_features_used(root)
+        self.assertNotIn(black.Feature.DEBUG_F_STRINGS, features)
+
+        # We don't yet support feature version detection in nested f-strings
+        root = black.lib2to3_parse(
+            """f"heard a rumour that { f'{1+1=}' } ... seems like it could be true" """
+        )
+        features = black.get_features_used(root)
+        self.assertNotIn(black.Feature.DEBUG_F_STRINGS, features)
+
     @patch("black.dump_to_file", dump_to_stderr)
     def test_string_quotes(self) -> None:
     @patch("black.dump_to_file", dump_to_stderr)
     def test_string_quotes(self) -> None:
-        source, expected = read_data("string_quotes")
+        source, expected = read_data("miscellaneous", "string_quotes")
         mode = black.Mode(preview=True)
         assert_format(source, expected, mode)
         mode = replace(mode, string_normalization=False)
         mode = black.Mode(preview=True)
         assert_format(source, expected, mode)
         mode = replace(mode, string_normalization=False)
@@ -316,16 +370,44 @@ class BlackTestCase(BlackBaseTestCase):
         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)
 
+    def test_skip_source_first_line(self) -> None:
+        source, _ = read_data("miscellaneous", "invalid_header")
+        tmp_file = Path(black.dump_to_file(source))
+        # Full source should fail (invalid syntax at header)
+        self.invokeBlack([str(tmp_file), "--diff", "--check"], exit_code=123)
+        # So, skipping the first line should work
+        result = BlackRunner().invoke(
+            black.main, [str(tmp_file), "-x", f"--config={EMPTY_CONFIG}"]
+        )
+        self.assertEqual(result.exit_code, 0)
+        with open(tmp_file, encoding="utf8") as f:
+            actual = f.read()
+        self.assertFormatEqual(source, actual)
+
+    def test_skip_source_first_line_when_mixing_newlines(self) -> None:
+        code_mixing_newlines = b"Header will be skipped\r\ni = [1,2,3]\nj = [1,2,3]\n"
+        expected = b"Header will be skipped\r\ni = [1, 2, 3]\nj = [1, 2, 3]\n"
+        with TemporaryDirectory() as workspace:
+            test_file = Path(workspace) / "skip_header.py"
+            test_file.write_bytes(code_mixing_newlines)
+            mode = replace(DEFAULT_MODE, skip_source_first_line=True)
+            ff(test_file, mode=mode, write_back=black.WriteBack.YES)
+            self.assertEqual(test_file.read_bytes(), expected)
+
     def test_skip_magic_trailing_comma(self) -> None:
     def test_skip_magic_trailing_comma(self) -> None:
-        source, _ = read_data("expression.py")
-        expected, _ = read_data("expression_skip_magic_trailing_comma.diff")
+        source, _ = read_data("simple_cases", "expression")
+        expected, _ = read_data(
+            "miscellaneous", "expression_skip_magic_trailing_comma.diff"
+        )
         tmp_file = Path(black.dump_to_file(source))
         diff_header = re.compile(
             rf"{re.escape(str(tmp_file))}\t\d\d\d\d-\d\d-\d\d "
             r"\d\d:\d\d:\d\d\.\d\d\d\d\d\d \+\d\d\d\d"
         )
         try:
         tmp_file = Path(black.dump_to_file(source))
         diff_header = re.compile(
             rf"{re.escape(str(tmp_file))}\t\d\d\d\d-\d\d-\d\d "
             r"\d\d:\d\d:\d\d\.\d\d\d\d\d\d \+\d\d\d\d"
         )
         try:
-            result = BlackRunner().invoke(black.main, ["-C", "--diff", str(tmp_file)])
+            result = BlackRunner().invoke(
+                black.main, ["-C", "--diff", str(tmp_file), f"--config={EMPTY_CONFIG}"]
+            )
             self.assertEqual(result.exit_code, 0)
         finally:
             os.unlink(tmp_file)
             self.assertEqual(result.exit_code, 0)
         finally:
             os.unlink(tmp_file)
@@ -343,8 +425,8 @@ class BlackTestCase(BlackBaseTestCase):
 
     @patch("black.dump_to_file", dump_to_stderr)
     def test_async_as_identifier(self) -> None:
 
     @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")
+        source_path = get_case_path("miscellaneous", "async_as_identifier")
+        source, expected = read_data_from_file(source_path)
         actual = fs(source)
         self.assertFormatEqual(expected, actual)
         major, minor = sys.version_info[:2]
         actual = fs(source)
         self.assertFormatEqual(expected, actual)
         major, minor = sys.version_info[:2]
@@ -358,8 +440,8 @@ class BlackTestCase(BlackBaseTestCase):
 
     @patch("black.dump_to_file", dump_to_stderr)
     def test_python37(self) -> None:
 
     @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")
+        source_path = get_case_path("py_37", "python37")
+        source, expected = read_data_from_file(source_path)
         actual = fs(source)
         self.assertFormatEqual(expected, actual)
         major, minor = sys.version_info[:2]
         actual = fs(source)
         self.assertFormatEqual(expected, actual)
         major, minor = sys.version_info[:2]
@@ -437,8 +519,10 @@ class BlackTestCase(BlackBaseTestCase):
             self.assertEqual(err_lines[-1], "error: cannot format e1: boom")
             self.assertEqual(
                 unstyle(str(report)),
             self.assertEqual(err_lines[-1], "error: cannot format e1: boom")
             self.assertEqual(
                 unstyle(str(report)),
-                "1 file reformatted, 2 files left unchanged, 1 file failed to"
-                " reformat.",
+                (
+                    "1 file reformatted, 2 files left unchanged, 1 file failed to"
+                    " reformat."
+                ),
             )
             self.assertEqual(report.return_code, 123)
             report.done(Path("f3"), black.Changed.YES)
             )
             self.assertEqual(report.return_code, 123)
             report.done(Path("f3"), black.Changed.YES)
@@ -447,8 +531,10 @@ class BlackTestCase(BlackBaseTestCase):
             self.assertEqual(out_lines[-1], "reformatted f3")
             self.assertEqual(
                 unstyle(str(report)),
             self.assertEqual(out_lines[-1], "reformatted f3")
             self.assertEqual(
                 unstyle(str(report)),
-                "2 files reformatted, 2 files left unchanged, 1 file failed to"
-                " reformat.",
+                (
+                    "2 files reformatted, 2 files left unchanged, 1 file failed to"
+                    " reformat."
+                ),
             )
             self.assertEqual(report.return_code, 123)
             report.failed(Path("e2"), "boom")
             )
             self.assertEqual(report.return_code, 123)
             report.failed(Path("e2"), "boom")
@@ -457,8 +543,10 @@ class BlackTestCase(BlackBaseTestCase):
             self.assertEqual(err_lines[-1], "error: cannot format e2: boom")
             self.assertEqual(
                 unstyle(str(report)),
             self.assertEqual(err_lines[-1], "error: cannot format e2: boom")
             self.assertEqual(
                 unstyle(str(report)),
-                "2 files reformatted, 2 files left unchanged, 2 files failed to"
-                " reformat.",
+                (
+                    "2 files reformatted, 2 files left unchanged, 2 files failed to"
+                    " reformat."
+                ),
             )
             self.assertEqual(report.return_code, 123)
             report.path_ignored(Path("wat"), "no match")
             )
             self.assertEqual(report.return_code, 123)
             report.path_ignored(Path("wat"), "no match")
@@ -467,8 +555,10 @@ class BlackTestCase(BlackBaseTestCase):
             self.assertEqual(out_lines[-1], "wat ignored: no match")
             self.assertEqual(
                 unstyle(str(report)),
             self.assertEqual(out_lines[-1], "wat ignored: no match")
             self.assertEqual(
                 unstyle(str(report)),
-                "2 files reformatted, 2 files left unchanged, 2 files failed to"
-                " reformat.",
+                (
+                    "2 files reformatted, 2 files left unchanged, 2 files failed to"
+                    " reformat."
+                ),
             )
             self.assertEqual(report.return_code, 123)
             report.done(Path("f4"), black.Changed.NO)
             )
             self.assertEqual(report.return_code, 123)
             report.done(Path("f4"), black.Changed.NO)
@@ -477,22 +567,28 @@ class BlackTestCase(BlackBaseTestCase):
             self.assertEqual(out_lines[-1], "f4 already well formatted, good job.")
             self.assertEqual(
                 unstyle(str(report)),
             self.assertEqual(out_lines[-1], "f4 already well formatted, good job.")
             self.assertEqual(
                 unstyle(str(report)),
-                "2 files reformatted, 3 files left unchanged, 2 files failed to"
-                " reformat.",
+                (
+                    "2 files reformatted, 3 files left unchanged, 2 files failed to"
+                    " reformat."
+                ),
             )
             self.assertEqual(report.return_code, 123)
             report.check = True
             self.assertEqual(
                 unstyle(str(report)),
             )
             self.assertEqual(report.return_code, 123)
             report.check = True
             self.assertEqual(
                 unstyle(str(report)),
-                "2 files would be reformatted, 3 files would be left unchanged, 2 files"
-                " would fail to reformat.",
+                (
+                    "2 files would be reformatted, 3 files would be left unchanged, 2"
+                    " files would fail to reformat."
+                ),
             )
             report.check = False
             report.diff = True
             self.assertEqual(
                 unstyle(str(report)),
             )
             report.check = False
             report.diff = True
             self.assertEqual(
                 unstyle(str(report)),
-                "2 files would be reformatted, 3 files would be left unchanged, 2 files"
-                " would fail to reformat.",
+                (
+                    "2 files would be reformatted, 3 files would be left unchanged, 2"
+                    " files would fail to reformat."
+                ),
             )
 
     def test_report_quiet(self) -> None:
             )
 
     def test_report_quiet(self) -> None:
@@ -534,8 +630,10 @@ class BlackTestCase(BlackBaseTestCase):
             self.assertEqual(err_lines[-1], "error: cannot format e1: boom")
             self.assertEqual(
                 unstyle(str(report)),
             self.assertEqual(err_lines[-1], "error: cannot format e1: boom")
             self.assertEqual(
                 unstyle(str(report)),
-                "1 file reformatted, 2 files left unchanged, 1 file failed to"
-                " reformat.",
+                (
+                    "1 file reformatted, 2 files left unchanged, 1 file failed to"
+                    " reformat."
+                ),
             )
             self.assertEqual(report.return_code, 123)
             report.done(Path("f3"), black.Changed.YES)
             )
             self.assertEqual(report.return_code, 123)
             report.done(Path("f3"), black.Changed.YES)
@@ -543,8 +641,10 @@ class BlackTestCase(BlackBaseTestCase):
             self.assertEqual(len(err_lines), 1)
             self.assertEqual(
                 unstyle(str(report)),
             self.assertEqual(len(err_lines), 1)
             self.assertEqual(
                 unstyle(str(report)),
-                "2 files reformatted, 2 files left unchanged, 1 file failed to"
-                " reformat.",
+                (
+                    "2 files reformatted, 2 files left unchanged, 1 file failed to"
+                    " reformat."
+                ),
             )
             self.assertEqual(report.return_code, 123)
             report.failed(Path("e2"), "boom")
             )
             self.assertEqual(report.return_code, 123)
             report.failed(Path("e2"), "boom")
@@ -553,8 +653,10 @@ class BlackTestCase(BlackBaseTestCase):
             self.assertEqual(err_lines[-1], "error: cannot format e2: boom")
             self.assertEqual(
                 unstyle(str(report)),
             self.assertEqual(err_lines[-1], "error: cannot format e2: boom")
             self.assertEqual(
                 unstyle(str(report)),
-                "2 files reformatted, 2 files left unchanged, 2 files failed to"
-                " reformat.",
+                (
+                    "2 files reformatted, 2 files left unchanged, 2 files failed to"
+                    " reformat."
+                ),
             )
             self.assertEqual(report.return_code, 123)
             report.path_ignored(Path("wat"), "no match")
             )
             self.assertEqual(report.return_code, 123)
             report.path_ignored(Path("wat"), "no match")
@@ -562,8 +664,10 @@ class BlackTestCase(BlackBaseTestCase):
             self.assertEqual(len(err_lines), 2)
             self.assertEqual(
                 unstyle(str(report)),
             self.assertEqual(len(err_lines), 2)
             self.assertEqual(
                 unstyle(str(report)),
-                "2 files reformatted, 2 files left unchanged, 2 files failed to"
-                " reformat.",
+                (
+                    "2 files reformatted, 2 files left unchanged, 2 files failed to"
+                    " reformat."
+                ),
             )
             self.assertEqual(report.return_code, 123)
             report.done(Path("f4"), black.Changed.NO)
             )
             self.assertEqual(report.return_code, 123)
             report.done(Path("f4"), black.Changed.NO)
@@ -571,22 +675,28 @@ class BlackTestCase(BlackBaseTestCase):
             self.assertEqual(len(err_lines), 2)
             self.assertEqual(
                 unstyle(str(report)),
             self.assertEqual(len(err_lines), 2)
             self.assertEqual(
                 unstyle(str(report)),
-                "2 files reformatted, 3 files left unchanged, 2 files failed to"
-                " reformat.",
+                (
+                    "2 files reformatted, 3 files left unchanged, 2 files failed to"
+                    " reformat."
+                ),
             )
             self.assertEqual(report.return_code, 123)
             report.check = True
             self.assertEqual(
                 unstyle(str(report)),
             )
             self.assertEqual(report.return_code, 123)
             report.check = True
             self.assertEqual(
                 unstyle(str(report)),
-                "2 files would be reformatted, 3 files would be left unchanged, 2 files"
-                " would fail to reformat.",
+                (
+                    "2 files would be reformatted, 3 files would be left unchanged, 2"
+                    " files would fail to reformat."
+                ),
             )
             report.check = False
             report.diff = True
             self.assertEqual(
                 unstyle(str(report)),
             )
             report.check = False
             report.diff = True
             self.assertEqual(
                 unstyle(str(report)),
-                "2 files would be reformatted, 3 files would be left unchanged, 2 files"
-                " would fail to reformat.",
+                (
+                    "2 files would be reformatted, 3 files would be left unchanged, 2"
+                    " files would fail to reformat."
+                ),
             )
 
     def test_report_normal(self) -> None:
             )
 
     def test_report_normal(self) -> None:
@@ -630,8 +740,10 @@ class BlackTestCase(BlackBaseTestCase):
             self.assertEqual(err_lines[-1], "error: cannot format e1: boom")
             self.assertEqual(
                 unstyle(str(report)),
             self.assertEqual(err_lines[-1], "error: cannot format e1: boom")
             self.assertEqual(
                 unstyle(str(report)),
-                "1 file reformatted, 2 files left unchanged, 1 file failed to"
-                " reformat.",
+                (
+                    "1 file reformatted, 2 files left unchanged, 1 file failed to"
+                    " reformat."
+                ),
             )
             self.assertEqual(report.return_code, 123)
             report.done(Path("f3"), black.Changed.YES)
             )
             self.assertEqual(report.return_code, 123)
             report.done(Path("f3"), black.Changed.YES)
@@ -640,8 +752,10 @@ class BlackTestCase(BlackBaseTestCase):
             self.assertEqual(out_lines[-1], "reformatted f3")
             self.assertEqual(
                 unstyle(str(report)),
             self.assertEqual(out_lines[-1], "reformatted f3")
             self.assertEqual(
                 unstyle(str(report)),
-                "2 files reformatted, 2 files left unchanged, 1 file failed to"
-                " reformat.",
+                (
+                    "2 files reformatted, 2 files left unchanged, 1 file failed to"
+                    " reformat."
+                ),
             )
             self.assertEqual(report.return_code, 123)
             report.failed(Path("e2"), "boom")
             )
             self.assertEqual(report.return_code, 123)
             report.failed(Path("e2"), "boom")
@@ -650,8 +764,10 @@ class BlackTestCase(BlackBaseTestCase):
             self.assertEqual(err_lines[-1], "error: cannot format e2: boom")
             self.assertEqual(
                 unstyle(str(report)),
             self.assertEqual(err_lines[-1], "error: cannot format e2: boom")
             self.assertEqual(
                 unstyle(str(report)),
-                "2 files reformatted, 2 files left unchanged, 2 files failed to"
-                " reformat.",
+                (
+                    "2 files reformatted, 2 files left unchanged, 2 files failed to"
+                    " reformat."
+                ),
             )
             self.assertEqual(report.return_code, 123)
             report.path_ignored(Path("wat"), "no match")
             )
             self.assertEqual(report.return_code, 123)
             report.path_ignored(Path("wat"), "no match")
@@ -659,8 +775,10 @@ class BlackTestCase(BlackBaseTestCase):
             self.assertEqual(len(err_lines), 2)
             self.assertEqual(
                 unstyle(str(report)),
             self.assertEqual(len(err_lines), 2)
             self.assertEqual(
                 unstyle(str(report)),
-                "2 files reformatted, 2 files left unchanged, 2 files failed to"
-                " reformat.",
+                (
+                    "2 files reformatted, 2 files left unchanged, 2 files failed to"
+                    " reformat."
+                ),
             )
             self.assertEqual(report.return_code, 123)
             report.done(Path("f4"), black.Changed.NO)
             )
             self.assertEqual(report.return_code, 123)
             report.done(Path("f4"), black.Changed.NO)
@@ -668,22 +786,28 @@ class BlackTestCase(BlackBaseTestCase):
             self.assertEqual(len(err_lines), 2)
             self.assertEqual(
                 unstyle(str(report)),
             self.assertEqual(len(err_lines), 2)
             self.assertEqual(
                 unstyle(str(report)),
-                "2 files reformatted, 3 files left unchanged, 2 files failed to"
-                " reformat.",
+                (
+                    "2 files reformatted, 3 files left unchanged, 2 files failed to"
+                    " reformat."
+                ),
             )
             self.assertEqual(report.return_code, 123)
             report.check = True
             self.assertEqual(
                 unstyle(str(report)),
             )
             self.assertEqual(report.return_code, 123)
             report.check = True
             self.assertEqual(
                 unstyle(str(report)),
-                "2 files would be reformatted, 3 files would be left unchanged, 2 files"
-                " would fail to reformat.",
+                (
+                    "2 files would be reformatted, 3 files would be left unchanged, 2"
+                    " files would fail to reformat."
+                ),
             )
             report.check = False
             report.diff = True
             self.assertEqual(
                 unstyle(str(report)),
             )
             report.check = False
             report.diff = True
             self.assertEqual(
                 unstyle(str(report)),
-                "2 files would be reformatted, 3 files would be left unchanged, 2 files"
-                " would fail to reformat.",
+                (
+                    "2 files would be reformatted, 3 files would be left unchanged, 2"
+                    " files would fail to reformat."
+                ),
             )
 
     def test_lib2to3_parse(self) -> None:
             )
 
     def test_lib2to3_parse(self) -> None:
@@ -707,7 +831,7 @@ class BlackTestCase(BlackBaseTestCase):
         # 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
         # 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")
+        simples, relaxed = read_data("miscellaneous", "decorators")
         # skip explanation comments at the top of the file
         for simple_test in simples.split("##")[1:]:
             node = black.lib2to3_parse(simple_test)
         # skip explanation comments at the top of the file
         for simple_test in simples.split("##")[1:]:
             node = black.lib2to3_parse(simple_test)
@@ -750,7 +874,7 @@ class BlackTestCase(BlackBaseTestCase):
         self.assertEqual(black.get_features_used(node), {Feature.NUMERIC_UNDERSCORES})
         node = black.lib2to3_parse("123456\n")
         self.assertEqual(black.get_features_used(node), set())
         self.assertEqual(black.get_features_used(node), {Feature.NUMERIC_UNDERSCORES})
         node = black.lib2to3_parse("123456\n")
         self.assertEqual(black.get_features_used(node), set())
-        source, expected = read_data("function")
+        source, expected = read_data("simple_cases", "function")
         node = black.lib2to3_parse(source)
         expected_features = {
             Feature.TRAILING_COMMA_IN_CALL,
         node = black.lib2to3_parse(source)
         expected_features = {
             Feature.TRAILING_COMMA_IN_CALL,
@@ -760,7 +884,7 @@ class BlackTestCase(BlackBaseTestCase):
         self.assertEqual(black.get_features_used(node), expected_features)
         node = black.lib2to3_parse(expected)
         self.assertEqual(black.get_features_used(node), expected_features)
         self.assertEqual(black.get_features_used(node), expected_features)
         node = black.lib2to3_parse(expected)
         self.assertEqual(black.get_features_used(node), expected_features)
-        source, expected = read_data("expression")
+        source, expected = read_data("simple_cases", "expression")
         node = black.lib2to3_parse(source)
         self.assertEqual(black.get_features_used(node), set())
         node = black.lib2to3_parse(expected)
         node = black.lib2to3_parse(source)
         self.assertEqual(black.get_features_used(node), set())
         node = black.lib2to3_parse(expected)
@@ -789,6 +913,18 @@ class BlackTestCase(BlackBaseTestCase):
         self.assertEqual(
             black.get_features_used(node), {Feature.ANN_ASSIGN_EXTENDED_RHS}
         )
         self.assertEqual(
             black.get_features_used(node), {Feature.ANN_ASSIGN_EXTENDED_RHS}
         )
+        node = black.lib2to3_parse("try: pass\nexcept Something: pass")
+        self.assertEqual(black.get_features_used(node), set())
+        node = black.lib2to3_parse("try: pass\nexcept (*Something,): pass")
+        self.assertEqual(black.get_features_used(node), set())
+        node = black.lib2to3_parse("try: pass\nexcept *Group: pass")
+        self.assertEqual(black.get_features_used(node), {Feature.EXCEPT_STAR})
+        node = black.lib2to3_parse("a[*b]")
+        self.assertEqual(black.get_features_used(node), {Feature.VARIADIC_GENERICS})
+        node = black.lib2to3_parse("a[x, *y(), z] = t")
+        self.assertEqual(black.get_features_used(node), {Feature.VARIADIC_GENERICS})
+        node = black.lib2to3_parse("def fn(*args: *T): pass")
+        self.assertEqual(black.get_features_used(node), {Feature.VARIADIC_GENERICS})
 
     def test_get_features_used_for_future_flags(self) -> None:
         for src, features in [
 
     def test_get_features_used_for_future_flags(self) -> None:
         for src, features in [
@@ -840,8 +976,8 @@ class BlackTestCase(BlackBaseTestCase):
 
     @pytest.mark.incompatible_with_mypyc
     def test_debug_visitor(self) -> None:
 
     @pytest.mark.incompatible_with_mypyc
     def test_debug_visitor(self) -> None:
-        source, _ = read_data("debug_visitor.py")
-        expected, _ = read_data("debug_visitor.out")
+        source, _ = read_data("miscellaneous", "debug_visitor")
+        expected, _ = read_data("miscellaneous", "debug_visitor.out")
         out_lines = []
         err_lines = []
 
         out_lines = []
         err_lines = []
 
@@ -864,8 +1000,8 @@ class BlackTestCase(BlackBaseTestCase):
         )
 
     def test_format_file_contents(self) -> None:
         )
 
     def test_format_file_contents(self) -> None:
-        empty = ""
         mode = DEFAULT_MODE
         mode = DEFAULT_MODE
+        empty = ""
         with self.assertRaises(black.NothingChanged):
             black.format_file_contents(empty, mode=mode, fast=False)
         just_nl = "\n"
         with self.assertRaises(black.NothingChanged):
             black.format_file_contents(empty, mode=mode, fast=False)
         just_nl = "\n"
@@ -883,6 +1019,17 @@ class BlackTestCase(BlackBaseTestCase):
             black.format_file_contents(invalid, mode=mode, fast=False)
         self.assertEqual(str(e.exception), "Cannot parse: 1:7: return if you can")
 
             black.format_file_contents(invalid, mode=mode, fast=False)
         self.assertEqual(str(e.exception), "Cannot parse: 1:7: return if you can")
 
+        mode = black.Mode(preview=True)
+        just_crlf = "\r\n"
+        with self.assertRaises(black.NothingChanged):
+            black.format_file_contents(just_crlf, mode=mode, fast=False)
+        just_whitespace_nl = "\n\t\n \n\t \n \t\n\n"
+        actual = black.format_file_contents(just_whitespace_nl, mode=mode, fast=False)
+        self.assertEqual("\n", actual)
+        just_whitespace_crlf = "\r\n\t\r\n \r\n\t \r\n \t\r\n\r\n"
+        actual = black.format_file_contents(just_whitespace_crlf, mode=mode, fast=False)
+        self.assertEqual("\r\n", actual)
+
     def test_endmarker(self) -> None:
         n = black.lib2to3_parse("\n")
         self.assertEqual(n.type, black.syms.file_input)
     def test_endmarker(self) -> None:
         n = black.lib2to3_parse("\n")
         self.assertEqual(n.type, black.syms.file_input)
@@ -911,7 +1058,7 @@ class BlackTestCase(BlackBaseTestCase):
         self.assertEqual("".join(err_lines), "")
 
     @event_loop()
         self.assertEqual("".join(err_lines), "")
 
     @event_loop()
-    @patch("black.ProcessPoolExecutor", MagicMock(side_effect=OSError))
+    @patch("concurrent.futures.ProcessPoolExecutor", MagicMock(side_effect=OSError))
     def test_works_in_mono_process_only_environment(self) -> None:
         with cache_dir() as workspace:
             for f in [
     def test_works_in_mono_process_only_environment(self) -> None:
         with cache_dir() as workspace:
             for f in [
@@ -925,10 +1072,10 @@ class BlackTestCase(BlackBaseTestCase):
     def test_check_diff_use_together(self) -> None:
         with cache_dir():
             # Files which will be reformatted.
     def test_check_diff_use_together(self) -> None:
         with cache_dir():
             # Files which will be reformatted.
-            src1 = (THIS_DIR / "data" / "string_quotes.py").resolve()
+            src1 = get_case_path("miscellaneous", "string_quotes")
             self.invokeBlack([str(src1), "--diff", "--check"], exit_code=1)
             # Files which will not be reformatted.
             self.invokeBlack([str(src1), "--diff", "--check"], exit_code=1)
             # Files which will not be reformatted.
-            src2 = (THIS_DIR / "data" / "composition.py").resolve()
+            src2 = get_case_path("simple_cases", "composition")
             self.invokeBlack([str(src2), "--diff", "--check"])
             # Multi file command.
             self.invokeBlack([str(src1), str(src2), "--diff", "--check"], exit_code=1)
             self.invokeBlack([str(src2), "--diff", "--check"])
             # Multi file command.
             self.invokeBlack([str(src1), str(src2), "--diff", "--check"], exit_code=1)
@@ -952,7 +1099,7 @@ class BlackTestCase(BlackBaseTestCase):
 
     def test_single_file_force_pyi(self) -> None:
         pyi_mode = replace(DEFAULT_MODE, is_pyi=True)
 
     def test_single_file_force_pyi(self) -> None:
         pyi_mode = replace(DEFAULT_MODE, is_pyi=True)
-        contents, expected = read_data("force_pyi")
+        contents, expected = read_data("miscellaneous", "force_pyi")
         with cache_dir() as workspace:
             path = (workspace / "file.py").resolve()
             with open(path, "w") as fh:
         with cache_dir() as workspace:
             path = (workspace / "file.py").resolve()
             with open(path, "w") as fh:
@@ -973,7 +1120,7 @@ class BlackTestCase(BlackBaseTestCase):
     def test_multi_file_force_pyi(self) -> None:
         reg_mode = DEFAULT_MODE
         pyi_mode = replace(DEFAULT_MODE, is_pyi=True)
     def test_multi_file_force_pyi(self) -> None:
         reg_mode = DEFAULT_MODE
         pyi_mode = replace(DEFAULT_MODE, is_pyi=True)
-        contents, expected = read_data("force_pyi")
+        contents, expected = read_data("miscellaneous", "force_pyi")
         with cache_dir() as workspace:
             paths = [
                 (workspace / "file1.py").resolve(),
         with cache_dir() as workspace:
             paths = [
                 (workspace / "file1.py").resolve(),
@@ -995,7 +1142,7 @@ class BlackTestCase(BlackBaseTestCase):
                 self.assertNotIn(str(path), normal_cache)
 
     def test_pipe_force_pyi(self) -> None:
                 self.assertNotIn(str(path), normal_cache)
 
     def test_pipe_force_pyi(self) -> None:
-        source, expected = read_data("force_pyi")
+        source, expected = read_data("miscellaneous", "force_pyi")
         result = CliRunner().invoke(
             black.main, ["-", "-q", "--pyi"], input=BytesIO(source.encode("utf8"))
         )
         result = CliRunner().invoke(
             black.main, ["-", "-q", "--pyi"], input=BytesIO(source.encode("utf8"))
         )
@@ -1006,7 +1153,7 @@ class BlackTestCase(BlackBaseTestCase):
     def test_single_file_force_py36(self) -> None:
         reg_mode = DEFAULT_MODE
         py36_mode = replace(DEFAULT_MODE, target_versions=PY36_VERSIONS)
     def test_single_file_force_py36(self) -> None:
         reg_mode = DEFAULT_MODE
         py36_mode = replace(DEFAULT_MODE, target_versions=PY36_VERSIONS)
-        source, expected = read_data("force_py36")
+        source, expected = read_data("miscellaneous", "force_py36")
         with cache_dir() as workspace:
             path = (workspace / "file.py").resolve()
             with open(path, "w") as fh:
         with cache_dir() as workspace:
             path = (workspace / "file.py").resolve()
             with open(path, "w") as fh:
@@ -1025,7 +1172,7 @@ class BlackTestCase(BlackBaseTestCase):
     def test_multi_file_force_py36(self) -> None:
         reg_mode = DEFAULT_MODE
         py36_mode = replace(DEFAULT_MODE, target_versions=PY36_VERSIONS)
     def test_multi_file_force_py36(self) -> None:
         reg_mode = DEFAULT_MODE
         py36_mode = replace(DEFAULT_MODE, target_versions=PY36_VERSIONS)
-        source, expected = read_data("force_py36")
+        source, expected = read_data("miscellaneous", "force_py36")
         with cache_dir() as workspace:
             paths = [
                 (workspace / "file1.py").resolve(),
         with cache_dir() as workspace:
             paths = [
                 (workspace / "file1.py").resolve(),
@@ -1047,7 +1194,7 @@ class BlackTestCase(BlackBaseTestCase):
                 self.assertNotIn(str(path), normal_cache)
 
     def test_pipe_force_py36(self) -> None:
                 self.assertNotIn(str(path), normal_cache)
 
     def test_pipe_force_py36(self) -> None:
-        source, expected = read_data("force_py36")
+        source, expected = read_data("miscellaneous", "force_py36")
         result = CliRunner().invoke(
             black.main,
             ["-", "-q", "--target-version=py36"],
         result = CliRunner().invoke(
             black.main,
             ["-", "-q", "--target-version=py36"],
@@ -1157,7 +1304,7 @@ class BlackTestCase(BlackBaseTestCase):
             report = MagicMock()
             # Even with an existing file, since we are forcing stdin, black
             # should output to stdout and not modify the file inplace
             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"))
+            p = THIS_DIR / "data" / "simple_cases" / "collections.py"
             # Make sure is_file actually returns True
             self.assertTrue(p.is_file())
             path = Path(f"__BLACK_STDIN_FILENAME__{p}")
             # Make sure is_file actually returns True
             self.assertTrue(p.is_file())
             path = Path(f"__BLACK_STDIN_FILENAME__{p}")
@@ -1174,8 +1321,51 @@ class BlackTestCase(BlackBaseTestCase):
             report.done.assert_called_with(expected, black.Changed.YES)
 
     def test_reformat_one_with_stdin_empty(self) -> None:
             report.done.assert_called_with(expected, black.Changed.YES)
 
     def test_reformat_one_with_stdin_empty(self) -> None:
+        cases = [
+            ("", ""),
+            ("\n", "\n"),
+            ("\r\n", "\r\n"),
+            (" \t", ""),
+            (" \t\n\t ", "\n"),
+            (" \t\r\n\t ", "\r\n"),
+        ]
+
+        def _new_wrapper(
+            output: io.StringIO, io_TextIOWrapper: Type[io.TextIOWrapper]
+        ) -> Callable[[Any, Any], io.TextIOWrapper]:
+            def get_output(*args: Any, **kwargs: Any) -> io.TextIOWrapper:
+                if args == (sys.stdout.buffer,):
+                    # It's `format_stdin_to_stdout()` calling `io.TextIOWrapper()`,
+                    # return our mock object.
+                    return output
+                # It's something else (i.e. `decode_bytes()`) calling
+                # `io.TextIOWrapper()`, pass through to the original implementation.
+                # See discussion in https://github.com/psf/black/pull/2489
+                return io_TextIOWrapper(*args, **kwargs)
+
+            return get_output
+
+        mode = black.Mode(preview=True)
+        for content, expected in cases:
+            output = io.StringIO()
+            io_TextIOWrapper = io.TextIOWrapper
+
+            with patch("io.TextIOWrapper", _new_wrapper(output, io_TextIOWrapper)):
+                try:
+                    black.format_stdin_to_stdout(
+                        fast=True,
+                        content=content,
+                        write_back=black.WriteBack.YES,
+                        mode=mode,
+                    )
+                except io.UnsupportedOperation:
+                    pass  # StringIO does not support detach
+                assert output.getvalue() == expected
+
+        # An empty string is the only test case for `preview=False`
         output = io.StringIO()
         output = io.StringIO()
-        with patch("io.TextIOWrapper", lambda *args, **kwargs: output):
+        io_TextIOWrapper = io.TextIOWrapper
+        with patch("io.TextIOWrapper", _new_wrapper(output, io_TextIOWrapper)):
             try:
                 black.format_stdin_to_stdout(
                     fast=True,
             try:
                 black.format_stdin_to_stdout(
                     fast=True,
@@ -1245,29 +1435,42 @@ class BlackTestCase(BlackBaseTestCase):
             if nl == "\n":
                 self.assertNotIn(b"\r\n", output)
 
             if nl == "\n":
                 self.assertNotIn(b"\r\n", output)
 
+    def test_normalize_line_endings(self) -> None:
+        with TemporaryDirectory() as workspace:
+            test_file = Path(workspace) / "test.py"
+            for data, expected in (
+                (b"c\r\nc\n ", b"c\r\nc\r\n"),
+                (b"l\nl\r\n ", b"l\nl\n"),
+            ):
+                test_file.write_bytes(data)
+                ff(test_file, write_back=black.WriteBack.YES)
+                self.assertEqual(test_file.read_bytes(), expected)
+
     def test_assert_equivalent_different_asts(self) -> None:
         with self.assertRaises(AssertionError):
             black.assert_equivalent("{}", "None")
 
     def test_shhh_click(self) -> None:
         try:
     def test_assert_equivalent_different_asts(self) -> None:
         with self.assertRaises(AssertionError):
             black.assert_equivalent("{}", "None")
 
     def test_shhh_click(self) -> None:
         try:
-            from click import _unicodefun
-        except ModuleNotFoundError:
+            from click import _unicodefun  # type: ignore
+        except ImportError:
             self.skipTest("Incompatible Click version")
             self.skipTest("Incompatible Click version")
-        if not hasattr(_unicodefun, "_verify_python3_env"):
+
+        if not hasattr(_unicodefun, "_verify_python_env"):
             self.skipTest("Incompatible Click version")
             self.skipTest("Incompatible Click version")
+
         # First, let's see if Click is crashing with a preferred ASCII charset.
         with patch("locale.getpreferredencoding") as gpe:
             gpe.return_value = "ASCII"
             with self.assertRaises(RuntimeError):
         # First, let's see if Click is crashing with a preferred ASCII charset.
         with patch("locale.getpreferredencoding") as gpe:
             gpe.return_value = "ASCII"
             with self.assertRaises(RuntimeError):
-                _unicodefun._verify_python3_env()  # type: ignore
+                _unicodefun._verify_python_env()
         # Now, let's silence Click...
         black.patch_click()
         # ...and confirm it's silent.
         with patch("locale.getpreferredencoding") as gpe:
             gpe.return_value = "ASCII"
             try:
         # Now, let's silence Click...
         black.patch_click()
         # ...and confirm it's silent.
         with patch("locale.getpreferredencoding") as gpe:
             gpe.return_value = "ASCII"
             try:
-                _unicodefun._verify_python3_env()  # type: ignore
+                _unicodefun._verify_python_env()
             except RuntimeError as re:
                 self.fail(f"`patch_click()` failed, exception still raised: {re}")
 
             except RuntimeError as re:
                 self.fail(f"`patch_click()` failed, exception still raised: {re}")
 
@@ -1353,6 +1556,27 @@ class BlackTestCase(BlackBaseTestCase):
                 (src_dir.resolve(), "pyproject.toml"),
             )
 
                 (src_dir.resolve(), "pyproject.toml"),
             )
 
+            with change_directory(test_dir):
+                self.assertEqual(
+                    black.find_project_root(("-",), stdin_filename="../src/a.py"),
+                    (src_dir.resolve(), "pyproject.toml"),
+                )
+
+    @patch(
+        "black.files.find_user_pyproject_toml",
+    )
+    def test_find_pyproject_toml(self, find_user_pyproject_toml: MagicMock) -> None:
+        find_user_pyproject_toml.side_effect = RuntimeError()
+
+        with redirect_stderr(io.StringIO()) as stderr:
+            result = black.files.find_pyproject_toml(
+                path_search_start=(str(Path.cwd().root),)
+            )
+
+        assert result is None
+        err = stderr.getvalue()
+        assert "Ignoring user configuration" in err
+
     @patch(
         "black.files.find_user_pyproject_toml",
         black.files.find_user_pyproject_toml.__wrapped__,
     @patch(
         "black.files.find_user_pyproject_toml",
         black.files.find_user_pyproject_toml.__wrapped__,
@@ -1398,19 +1622,37 @@ class BlackTestCase(BlackBaseTestCase):
             normalized_path = black.normalize_path_maybe_ignore(path, root, report)
             self.assertEqual(normalized_path, "workspace/project")
 
             normalized_path = black.normalize_path_maybe_ignore(path, root, report)
             self.assertEqual(normalized_path, "workspace/project")
 
+    def test_normalize_path_ignore_windows_junctions_outside_of_root(self) -> None:
+        if system() != "Windows":
+            return
+
+        with TemporaryDirectory() as workspace:
+            root = Path(workspace)
+            junction_dir = root / "junction"
+            junction_target_outside_of_root = root / ".."
+            os.system(f"mklink /J {junction_dir} {junction_target_outside_of_root}")
+
+            report = black.Report(verbose=True)
+            normalized_path = black.normalize_path_maybe_ignore(
+                junction_dir, root, report
+            )
+            # Manually delete for Python < 3.8
+            os.system(f"rmdir {junction_dir}")
+
+            self.assertEqual(normalized_path, None)
+
     def test_newline_comment_interaction(self) -> None:
         source = "class A:\\\r\n# type: ignore\n pass\n"
         output = black.format_str(source, mode=DEFAULT_MODE)
         black.assert_stable(source, output, mode=DEFAULT_MODE)
 
     def test_bpo_2142_workaround(self) -> None:
     def test_newline_comment_interaction(self) -> None:
         source = "class A:\\\r\n# type: ignore\n pass\n"
         output = black.format_str(source, mode=DEFAULT_MODE)
         black.assert_stable(source, output, mode=DEFAULT_MODE)
 
     def test_bpo_2142_workaround(self) -> None:
-
         # https://bugs.python.org/issue2142
 
         # https://bugs.python.org/issue2142
 
-        source, _ = read_data("missing_final_newline.py")
+        source, _ = read_data("miscellaneous", "missing_final_newline")
         # read_data adds a trailing newline
         source = source.rstrip()
         # read_data adds a trailing newline
         source = source.rstrip()
-        expected, _ = read_data("missing_final_newline.diff")
+        expected, _ = read_data("miscellaneous", "missing_final_newline.diff")
         tmp_file = Path(black.dump_to_file(source, ensure_final_newline=False))
         diff_header = re.compile(
             rf"{re.escape(str(tmp_file))}\t\d\d\d\d-\d\d-\d\d "
         tmp_file = Path(black.dump_to_file(source, ensure_final_newline=False))
         diff_header = re.compile(
             rf"{re.escape(str(tmp_file))}\t\d\d\d\d-\d\d-\d\d "
@@ -1636,7 +1878,7 @@ class TestCaching:
     def test_cache_multiple_files(self) -> None:
         mode = DEFAULT_MODE
         with cache_dir() as workspace, patch(
     def test_cache_multiple_files(self) -> None:
         mode = DEFAULT_MODE
         with cache_dir() as workspace, patch(
-            "black.ProcessPoolExecutor", new=ThreadPoolExecutor
+            "concurrent.futures.ProcessPoolExecutor", new=ThreadPoolExecutor
         ):
             one = (workspace / "one.py").resolve()
             with one.open("w") as fobj:
         ):
             one = (workspace / "one.py").resolve()
             with one.open("w") as fobj:
@@ -1681,7 +1923,9 @@ class TestCaching:
                 src = (workspace / f"test{tag}.py").resolve()
                 with src.open("w") as fobj:
                     fobj.write("print('hello')")
                 src = (workspace / f"test{tag}.py").resolve()
                 with src.open("w") as fobj:
                     fobj.write("print('hello')")
-            with patch("black.Manager", wraps=multiprocessing.Manager) as mgr:
+            with patch(
+                "black.concurrency.Manager", wraps=multiprocessing.Manager
+            ) as mgr:
                 cmd = ["--diff", str(workspace)]
                 if color:
                     cmd.append("--color")
                 cmd = ["--diff", str(workspace)]
                 if color:
                     cmd.append("--color")
@@ -1728,7 +1972,7 @@ class TestCaching:
                 str(cached): black.get_cache_info(cached),
                 str(cached_but_changed): (0.0, 0),
             }
                 str(cached): black.get_cache_info(cached),
                 str(cached_but_changed): (0.0, 0),
             }
-            todo, done = black.filter_cached(
+            todo, done = black.cache.filter_cached(
                 cache, {uncached, cached, cached_but_changed}
             )
             assert todo == {uncached, cached_but_changed}
                 cache, {uncached, cached, cached_but_changed}
             )
             assert todo == {uncached, cached_but_changed}
@@ -1745,7 +1989,7 @@ class TestCaching:
     def test_failed_formatting_does_not_get_cached(self) -> None:
         mode = DEFAULT_MODE
         with cache_dir() as workspace, patch(
     def test_failed_formatting_does_not_get_cached(self) -> None:
         mode = DEFAULT_MODE
         with cache_dir() as workspace, patch(
-            "black.ProcessPoolExecutor", new=ThreadPoolExecutor
+            "concurrent.futures.ProcessPoolExecutor", new=ThreadPoolExecutor
         ):
             failing = (workspace / "failing.py").resolve()
             with failing.open("w") as fobj:
         ):
             failing = (workspace / "failing.py").resolve()
             with failing.open("w") as fobj:
@@ -1837,6 +2081,17 @@ class TestFileCollection:
         ctx.obj["root"] = base
         assert_collected_sources(src, expected, ctx=ctx, extend_exclude=r"/exclude/")
 
         ctx.obj["root"] = base
         assert_collected_sources(src, expected, ctx=ctx, extend_exclude=r"/exclude/")
 
+    def test_gitignore_used_on_multiple_sources(self) -> None:
+        root = Path(DATA_DIR / "gitignore_used_on_multiple_sources")
+        expected = [
+            root / "dir1" / "b.py",
+            root / "dir2" / "b.py",
+        ]
+        ctx = FakeContext()
+        ctx.obj["root"] = root
+        src = [root / "dir1", root / "dir2"]
+        assert_collected_sources(src, expected, ctx=ctx)
+
     @patch("black.find_project_root", lambda *args: (THIS_DIR.resolve(), None))
     def test_exclude_for_issue_1572(self) -> None:
         # Exclude shouldn't touch files that were explicitly given to Black through the
     @patch("black.find_project_root", lambda *args: (THIS_DIR.resolve(), None))
     def test_exclude_for_issue_1572(self) -> None:
         # Exclude shouldn't touch files that were explicitly given to Black through the
@@ -1870,7 +2125,7 @@ class TestFileCollection:
                 None,
                 None,
                 report,
                 None,
                 None,
                 report,
-                gitignore,
+                {path: gitignore},
                 verbose=False,
                 quiet=False,
             )
                 verbose=False,
                 quiet=False,
             )
@@ -1899,13 +2154,20 @@ class TestFileCollection:
                 None,
                 None,
                 report,
                 None,
                 None,
                 report,
-                root_gitignore,
+                {path: root_gitignore},
                 verbose=False,
                 quiet=False,
             )
         )
         assert sorted(expected) == sorted(sources)
 
                 verbose=False,
                 quiet=False,
             )
         )
         assert sorted(expected) == sorted(sources)
 
+    def test_nested_gitignore_directly_in_source_directory(self) -> None:
+        # https://github.com/psf/black/issues/2598
+        path = Path(DATA_DIR / "nested_gitignore_tests")
+        src = Path(path / "root" / "child")
+        expected = [src / "a.py", src / "c.py"]
+        assert_collected_sources([src], expected)
+
     def test_invalid_gitignore(self) -> None:
         path = THIS_DIR / "data" / "invalid_gitignore_tests"
         empty_config = path / "pyproject.toml"
     def test_invalid_gitignore(self) -> None:
         path = THIS_DIR / "data" / "invalid_gitignore_tests"
         empty_config = path / "pyproject.toml"
@@ -1930,6 +2192,32 @@ class TestFileCollection:
         gitignore = path / "a" / ".gitignore"
         assert f"Could not parse {gitignore}" in result.stderr_bytes.decode()
 
         gitignore = path / "a" / ".gitignore"
         assert f"Could not parse {gitignore}" in result.stderr_bytes.decode()
 
+    def test_gitignore_that_ignores_subfolders(self) -> None:
+        # If gitignore with */* is in root
+        root = Path(DATA_DIR / "ignore_subfolders_gitignore_tests" / "subdir")
+        expected = [root / "b.py"]
+        ctx = FakeContext()
+        ctx.obj["root"] = root
+        assert_collected_sources([root], expected, ctx=ctx)
+
+        # If .gitignore with */* is nested
+        root = Path(DATA_DIR / "ignore_subfolders_gitignore_tests")
+        expected = [
+            root / "a.py",
+            root / "subdir" / "b.py",
+        ]
+        ctx = FakeContext()
+        ctx.obj["root"] = root
+        assert_collected_sources([root], expected, ctx=ctx)
+
+        # If command is executed from outer dir
+        root = Path(DATA_DIR / "ignore_subfolders_gitignore_tests")
+        target = root / "subdir"
+        expected = [target / "b.py"]
+        ctx = FakeContext()
+        ctx.obj["root"] = root
+        assert_collected_sources([target], expected, ctx=ctx)
+
     def test_empty_include(self) -> None:
         path = DATA_DIR / "include_exclude_tests"
         src = [path]
     def test_empty_include(self) -> None:
         path = DATA_DIR / "include_exclude_tests"
         src = [path]
@@ -1974,7 +2262,6 @@ class TestFileCollection:
         path.iterdir.return_value = [child]
         child.resolve.return_value = Path("/a/b/c")
         child.as_posix.return_value = "/a/b/c"
         path.iterdir.return_value = [child]
         child.resolve.return_value = Path("/a/b/c")
         child.as_posix.return_value = "/a/b/c"
-        child.is_symlink.return_value = True
         try:
             list(
                 black.gen_python_files(
         try:
             list(
                 black.gen_python_files(
@@ -1985,7 +2272,7 @@ class TestFileCollection:
                     None,
                     None,
                     report,
                     None,
                     None,
                     report,
-                    gitignore,
+                    {path: gitignore},
                     verbose=False,
                     quiet=False,
                 )
                     verbose=False,
                     quiet=False,
                 )
@@ -1994,31 +2281,6 @@ class TestFileCollection:
             pytest.fail(f"`get_python_files_in_dir()` failed: {ve}")
         path.iterdir.assert_called_once()
         child.resolve.assert_called_once()
             pytest.fail(f"`get_python_files_in_dir()` failed: {ve}")
         path.iterdir.assert_called_once()
         child.resolve.assert_called_once()
-        child.is_symlink.assert_called_once()
-        # `child` should behave like a strange file which resolved path is clearly
-        # outside of the `root` directory.
-        child.is_symlink.return_value = False
-        with pytest.raises(ValueError):
-            list(
-                black.gen_python_files(
-                    path.iterdir(),
-                    root,
-                    include,
-                    exclude,
-                    None,
-                    None,
-                    report,
-                    gitignore,
-                    verbose=False,
-                    quiet=False,
-                )
-            )
-        path.iterdir.assert_called()
-        assert path.iterdir.call_count == 2
-        child.resolve.assert_called()
-        assert child.resolve.call_count == 2
-        child.is_symlink.assert_called()
-        assert child.is_symlink.call_count == 2
 
     @patch("black.find_project_root", lambda *args: (THIS_DIR.resolve(), None))
     def test_get_sources_with_stdin(self) -> None:
 
     @patch("black.find_project_root", lambda *args: (THIS_DIR.resolve(), None))
     def test_get_sources_with_stdin(self) -> None: