Adding upstream version 4.5.0+dfsg.upstream/4.5.0+dfsgupstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

35 files changed, 2426 insertions, 0 deletions

diff --git a/pre_commit_hooks/__init__.py b/pre_commit_hooks/__init__.py
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/pre_commit_hooks/__init__.py
diff --git a/pre_commit_hooks/check_added_large_files.py b/pre_commit_hooks/check_added_large_files.py
new file mode 100644
index 0000000..9e0619b
--- /dev/null
+++ b/pre_commit_hooks/check_added_large_files.py
@@ -0,0 +1,81 @@
+from __future__ import annotations
+
+import argparse
+import math
+import os
+import subprocess
+from typing import Sequence
+
+from pre_commit_hooks.util import added_files
+from pre_commit_hooks.util import zsplit
+
+
+def filter_lfs_files(filenames: set[str]) -> None:  # pragma: no cover (lfs)
+    """Remove files tracked by git-lfs from the set."""
+    if not filenames:
+        return
+
+    check_attr = subprocess.run(
+        ('git', 'check-attr', 'filter', '-z', '--stdin'),
+        stdout=subprocess.PIPE,
+        stderr=subprocess.DEVNULL,
+        encoding='utf-8',
+        check=True,
+        input='\0'.join(filenames),
+    )
+    stdout = zsplit(check_attr.stdout)
+    for i in range(0, len(stdout), 3):
+        filename, filter_tag = stdout[i], stdout[i + 2]
+        if filter_tag == 'lfs':
+            filenames.remove(filename)
+
+
+def find_large_added_files(
+        filenames: Sequence[str],
+        maxkb: int,
+        *,
+        enforce_all: bool = False,
+) -> int:
+    # Find all added files that are also in the list of files pre-commit tells
+    # us about
+    retv = 0
+    filenames_filtered = set(filenames)
+    filter_lfs_files(filenames_filtered)
+
+    if not enforce_all:
+        filenames_filtered &= added_files()
+
+    for filename in filenames_filtered:
+        kb = math.ceil(os.stat(filename).st_size / 1024)
+        if kb > maxkb:
+            print(f'{filename} ({kb} KB) exceeds {maxkb} KB.')
+            retv = 1
+
+    return retv
+
+
+def main(argv: Sequence[str] | None = None) -> int:
+    parser = argparse.ArgumentParser()
+    parser.add_argument(
+        'filenames', nargs='*',
+        help='Filenames pre-commit believes are changed.',
+    )
+    parser.add_argument(
+        '--enforce-all', action='store_true',
+        help='Enforce all files are checked, not just staged files.',
+    )
+    parser.add_argument(
+        '--maxkb', type=int, default=500,
+        help='Maximum allowable KB for added files',
+    )
+    args = parser.parse_args(argv)
+
+    return find_large_added_files(
+        args.filenames,
+        args.maxkb,
+        enforce_all=args.enforce_all,
+    )
+
+
+if __name__ == '__main__':
+    raise SystemExit(main())
diff --git a/pre_commit_hooks/check_ast.py b/pre_commit_hooks/check_ast.py
new file mode 100644
index 0000000..fdac361
--- /dev/null
+++ b/pre_commit_hooks/check_ast.py
@@ -0,0 +1,33 @@
+from __future__ import annotations
+
+import argparse
+import ast
+import platform
+import sys
+import traceback
+from typing import Sequence
+
+
+def main(argv: Sequence[str] | None = None) -> int:
+    parser = argparse.ArgumentParser()
+    parser.add_argument('filenames', nargs='*')
+    args = parser.parse_args(argv)
+
+    retval = 0
+    for filename in args.filenames:
+
+        try:
+            with open(filename, 'rb') as f:
+                ast.parse(f.read(), filename=filename)
+        except SyntaxError:
+            impl = platform.python_implementation()
+            version = sys.version.split()[0]
+            print(f'{filename}: failed parsing with {impl} {version}:')
+            tb = '    ' + traceback.format_exc().replace('\n', '\n    ')
+            print(f'\n{tb}')
+            retval = 1
+    return retval
+
+
+if __name__ == '__main__':
+    raise SystemExit(main())
diff --git a/pre_commit_hooks/check_builtin_literals.py b/pre_commit_hooks/check_builtin_literals.py
new file mode 100644
index 0000000..d3054aa
--- /dev/null
+++ b/pre_commit_hooks/check_builtin_literals.py
@@ -0,0 +1,105 @@
+from __future__ import annotations
+
+import argparse
+import ast
+from typing import NamedTuple
+from typing import Sequence
+
+
+BUILTIN_TYPES = {
+    'complex': '0j',
+    'dict': '{}',
+    'float': '0.0',
+    'int': '0',
+    'list': '[]',
+    'str': "''",
+    'tuple': '()',
+}
+
+
+class Call(NamedTuple):
+    name: str
+    line: int
+    column: int
+
+
+class Visitor(ast.NodeVisitor):
+    def __init__(
+            self,
+            ignore: Sequence[str] | None = None,
+            allow_dict_kwargs: bool = True,
+    ) -> None:
+        self.builtin_type_calls: list[Call] = []
+        self.ignore = set(ignore) if ignore else set()
+        self.allow_dict_kwargs = allow_dict_kwargs
+
+    def _check_dict_call(self, node: ast.Call) -> bool:
+        return self.allow_dict_kwargs and bool(node.keywords)
+
+    def visit_Call(self, node: ast.Call) -> None:
+        if not isinstance(node.func, ast.Name):
+            # Ignore functions that are object attributes (`foo.bar()`).
+            # Assume that if the user calls `builtins.list()`, they know what
+            # they're doing.
+            return
+        if node.func.id not in set(BUILTIN_TYPES).difference(self.ignore):
+            return
+        if node.func.id == 'dict' and self._check_dict_call(node):
+            return
+        elif node.args:
+            return
+        self.builtin_type_calls.append(
+            Call(node.func.id, node.lineno, node.col_offset),
+        )
+
+
+def check_file(
+        filename: str,
+        ignore: Sequence[str] | None = None,
+        allow_dict_kwargs: bool = True,
+) -> list[Call]:
+    with open(filename, 'rb') as f:
+        tree = ast.parse(f.read(), filename=filename)
+    visitor = Visitor(ignore=ignore, allow_dict_kwargs=allow_dict_kwargs)
+    visitor.visit(tree)
+    return visitor.builtin_type_calls
+
+
+def parse_ignore(value: str) -> set[str]:
+    return set(value.split(','))
+
+
+def main(argv: Sequence[str] | None = None) -> int:
+    parser = argparse.ArgumentParser()
+    parser.add_argument('filenames', nargs='*')
+    parser.add_argument('--ignore', type=parse_ignore, default=set())
+
+    mutex = parser.add_mutually_exclusive_group(required=False)
+    mutex.add_argument('--allow-dict-kwargs', action='store_true')
+    mutex.add_argument(
+        '--no-allow-dict-kwargs',
+        dest='allow_dict_kwargs', action='store_false',
+    )
+    mutex.set_defaults(allow_dict_kwargs=True)
+
+    args = parser.parse_args(argv)
+
+    rc = 0
+    for filename in args.filenames:
+        calls = check_file(
+            filename,
+            ignore=args.ignore,
+            allow_dict_kwargs=args.allow_dict_kwargs,
+        )
+        if calls:
+            rc = rc or 1
+        for call in calls:
+            print(
+                f'{filename}:{call.line}:{call.column}: '
+                f'replace {call.name}() with {BUILTIN_TYPES[call.name]}',
+            )
+    return rc
+
+
+if __name__ == '__main__':
+    raise SystemExit(main())
diff --git a/pre_commit_hooks/check_byte_order_marker.py b/pre_commit_hooks/check_byte_order_marker.py
new file mode 100644
index 0000000..59cc561
--- /dev/null
+++ b/pre_commit_hooks/check_byte_order_marker.py
@@ -0,0 +1,24 @@
+from __future__ import annotations
+
+import argparse
+from typing import Sequence
+
+
+def main(argv: Sequence[str] | None = None) -> int:
+    parser = argparse.ArgumentParser()
+    parser.add_argument('filenames', nargs='*', help='Filenames to check')
+    args = parser.parse_args(argv)
+
+    retv = 0
+
+    for filename in args.filenames:
+        with open(filename, 'rb') as f:
+            if f.read(3) == b'\xef\xbb\xbf':
+                retv = 1
+                print(f'{filename}: Has a byte-order marker')
+
+    return retv
+
+
+if __name__ == '__main__':
+    raise SystemExit(main())
diff --git a/pre_commit_hooks/check_case_conflict.py b/pre_commit_hooks/check_case_conflict.py
new file mode 100644
index 0000000..33a13f1
--- /dev/null
+++ b/pre_commit_hooks/check_case_conflict.py
@@ -0,0 +1,72 @@
+from __future__ import annotations
+
+import argparse
+from typing import Iterable
+from typing import Iterator
+from typing import Sequence
+
+from pre_commit_hooks.util import added_files
+from pre_commit_hooks.util import cmd_output
+
+
+def lower_set(iterable: Iterable[str]) -> set[str]:
+    return {x.lower() for x in iterable}
+
+
+def parents(file: str) -> Iterator[str]:
+    path_parts = file.split('/')
+    path_parts.pop()
+    while path_parts:
+        yield '/'.join(path_parts)
+        path_parts.pop()
+
+
+def directories_for(files: set[str]) -> set[str]:
+    return {parent for file in files for parent in parents(file)}
+
+
+def find_conflicting_filenames(filenames: Sequence[str]) -> int:
+    repo_files = set(cmd_output('git', 'ls-files').splitlines())
+    repo_files |= directories_for(repo_files)
+    relevant_files = set(filenames) | added_files()
+    relevant_files |= directories_for(relevant_files)
+    repo_files -= relevant_files
+    retv = 0
+
+    # new file conflicts with existing file
+    conflicts = lower_set(repo_files) & lower_set(relevant_files)
+
+    # new file conflicts with other new file
+    lowercase_relevant_files = lower_set(relevant_files)
+    for filename in set(relevant_files):
+        if filename.lower() in lowercase_relevant_files:
+            lowercase_relevant_files.remove(filename.lower())
+        else:
+            conflicts.add(filename.lower())
+
+    if conflicts:
+        conflicting_files = [
+            x for x in repo_files | relevant_files
+            if x.lower() in conflicts
+        ]
+        for filename in sorted(conflicting_files):
+            print(f'Case-insensitivity conflict found: {filename}')
+        retv = 1
+
+    return retv
+
+
+def main(argv: Sequence[str] | None = None) -> int:
+    parser = argparse.ArgumentParser()
+    parser.add_argument(
+        'filenames', nargs='*',
+        help='Filenames pre-commit believes are changed.',
+    )
+
+    args = parser.parse_args(argv)
+
+    return find_conflicting_filenames(args.filenames)
+
+
+if __name__ == '__main__':
+    raise SystemExit(main())
diff --git a/pre_commit_hooks/check_docstring_first.py b/pre_commit_hooks/check_docstring_first.py
new file mode 100644
index 0000000..d55f08a
--- /dev/null
+++ b/pre_commit_hooks/check_docstring_first.py
@@ -0,0 +1,61 @@
+from __future__ import annotations
+
+import argparse
+import io
+import tokenize
+from tokenize import tokenize as tokenize_tokenize
+from typing import Sequence
+
+NON_CODE_TOKENS = frozenset((
+    tokenize.COMMENT, tokenize.ENDMARKER, tokenize.NEWLINE, tokenize.NL,
+    tokenize.ENCODING,
+))
+
+
+def check_docstring_first(src: bytes, filename: str = '<unknown>') -> int:
+    """Returns nonzero if the source has what looks like a docstring that is
+    not at the beginning of the source.
+
+    A string will be considered a docstring if it is a STRING token with a
+    col offset of 0.
+    """
+    found_docstring_line = None
+    found_code_line = None
+
+    tok_gen = tokenize_tokenize(io.BytesIO(src).readline)
+    for tok_type, _, (sline, scol), _, _ in tok_gen:
+        # Looks like a docstring!
+        if tok_type == tokenize.STRING and scol == 0:
+            if found_docstring_line is not None:
+                print(
+                    f'{filename}:{sline}: Multiple module docstrings '
+                    f'(first docstring on line {found_docstring_line}).',
+                )
+                return 1
+            elif found_code_line is not None:
+                print(
+                    f'{filename}:{sline}: Module docstring appears after code '
+                    f'(code seen on line {found_code_line}).',
+                )
+                return 1
+            else:
+                found_docstring_line = sline
+        elif tok_type not in NON_CODE_TOKENS and found_code_line is None:
+            found_code_line = sline
+
+    return 0
+
+
+def main(argv: Sequence[str] | None = None) -> int:
+    parser = argparse.ArgumentParser()
+    parser.add_argument('filenames', nargs='*')
+    args = parser.parse_args(argv)
+
+    retv = 0
+
+    for filename in args.filenames:
+        with open(filename, 'rb') as f:
+            contents = f.read()
+        retv |= check_docstring_first(contents, filename=filename)
+
+    return retv
diff --git a/pre_commit_hooks/check_executables_have_shebangs.py b/pre_commit_hooks/check_executables_have_shebangs.py
new file mode 100644
index 0000000..d8e4f49
--- /dev/null
+++ b/pre_commit_hooks/check_executables_have_shebangs.py
@@ -0,0 +1,85 @@
+"""Check that executable text files have a shebang."""
+from __future__ import annotations
+
+import argparse
+import shlex
+import sys
+from typing import Generator
+from typing import NamedTuple
+from typing import Sequence
+
+from pre_commit_hooks.util import cmd_output
+from pre_commit_hooks.util import zsplit
+
+EXECUTABLE_VALUES = frozenset(('1', '3', '5', '7'))
+
+
+def check_executables(paths: list[str]) -> int:
+    fs_tracks_executable_bit = cmd_output(
+        'git', 'config', 'core.fileMode', retcode=None,
+    ).strip()
+    if fs_tracks_executable_bit == 'false':  # pragma: win32 cover
+        return _check_git_filemode(paths)
+    else:  # pragma: win32 no cover
+        retv = 0
+        for path in paths:
+            if not has_shebang(path):
+                _message(path)
+                retv = 1
+
+        return retv
+
+
+class GitLsFile(NamedTuple):
+    mode: str
+    filename: str
+
+
+def git_ls_files(paths: Sequence[str]) -> Generator[GitLsFile, None, None]:
+    outs = cmd_output('git', 'ls-files', '-z', '--stage', '--', *paths)
+    for out in zsplit(outs):
+        metadata, filename = out.split('\t')
+        mode, _, _ = metadata.split()
+        yield GitLsFile(mode, filename)
+
+
+def _check_git_filemode(paths: Sequence[str]) -> int:
+    seen: set[str] = set()
+    for ls_file in git_ls_files(paths):
+        is_executable = any(b in EXECUTABLE_VALUES for b in ls_file.mode[-3:])
+        if is_executable and not has_shebang(ls_file.filename):
+            _message(ls_file.filename)
+            seen.add(ls_file.filename)
+
+    return int(bool(seen))
+
+
+def has_shebang(path: str) -> int:
+    with open(path, 'rb') as f:
+        first_bytes = f.read(2)
+
+    return first_bytes == b'#!'
+
+
+def _message(path: str) -> None:
+    print(
+        f'{path}: marked executable but has no (or invalid) shebang!\n'
+        f"  If it isn't supposed to be executable, try: "
+        f'`chmod -x {shlex.quote(path)}`\n'
+        f'  If on Windows, you may also need to: '
+        f'`git add --chmod=-x {shlex.quote(path)}`\n'
+        f'  If it is supposed to be executable, double-check its shebang.',
+        file=sys.stderr,
+    )
+
+
+def main(argv: Sequence[str] | None = None) -> int:
+    parser = argparse.ArgumentParser(description=__doc__)
+    parser.add_argument('filenames', nargs='*')
+    args = parser.parse_args(argv)
+
+    return check_executables(args.filenames)
+
+
+if __name__ == '__main__':
+    raise SystemExit(main())
diff --git a/pre_commit_hooks/check_json.py b/pre_commit_hooks/check_json.py
new file mode 100644
index 0000000..6a679fe
--- /dev/null
+++ b/pre_commit_hooks/check_json.py
@@ -0,0 +1,38 @@
+from __future__ import annotations
+
+import argparse
+import json
+from typing import Any
+from typing import Sequence
+
+
+def raise_duplicate_keys(
+        ordered_pairs: list[tuple[str, Any]],
+) -> dict[str, Any]:
+    d = {}
+    for key, val in ordered_pairs:
+        if key in d:
+            raise ValueError(f'Duplicate key: {key}')
+        else:
+            d[key] = val
+    return d
+
+
+def main(argv: Sequence[str] | None = None) -> int:
+    parser = argparse.ArgumentParser()
+    parser.add_argument('filenames', nargs='*', help='Filenames to check.')
+    args = parser.parse_args(argv)
+
+    retval = 0
+    for filename in args.filenames:
+        with open(filename, 'rb') as f:
+            try:
+                json.load(f, object_pairs_hook=raise_duplicate_keys)
+            except ValueError as exc:
+                print(f'{filename}: Failed to json decode ({exc})')
+                retval = 1
+    return retval
+
+
+if __name__ == '__main__':
+    raise SystemExit(main())
diff --git a/pre_commit_hooks/check_merge_conflict.py b/pre_commit_hooks/check_merge_conflict.py
new file mode 100644
index 0000000..15ec284
--- /dev/null
+++ b/pre_commit_hooks/check_merge_conflict.py
@@ -0,0 +1,56 @@
+from __future__ import annotations
+
+import argparse
+import os.path
+from typing import Sequence
+
+from pre_commit_hooks.util import cmd_output
+
+
+CONFLICT_PATTERNS = [
+    b'<<<<<<< ',
+    b'======= ',
+    b'=======\r\n',
+    b'=======\n',
+    b'>>>>>>> ',
+]
+
+
+def is_in_merge() -> bool:
+    git_dir = cmd_output('git', 'rev-parse', '--git-dir').rstrip()
+    return (
+        os.path.exists(os.path.join(git_dir, 'MERGE_MSG')) and
+        (
+            os.path.exists(os.path.join(git_dir, 'MERGE_HEAD')) or
+            os.path.exists(os.path.join(git_dir, 'rebase-apply')) or
+            os.path.exists(os.path.join(git_dir, 'rebase-merge'))
+        )
+    )
+
+
+def main(argv: Sequence[str] | None = None) -> int:
+    parser = argparse.ArgumentParser()
+    parser.add_argument('filenames', nargs='*')
+    parser.add_argument('--assume-in-merge', action='store_true')
+    args = parser.parse_args(argv)
+
+    if not is_in_merge() and not args.assume_in_merge:
+        return 0
+
+    retcode = 0
+    for filename in args.filenames:
+        with open(filename, 'rb') as inputfile:
+            for i, line in enumerate(inputfile, start=1):
+                for pattern in CONFLICT_PATTERNS:
+                    if line.startswith(pattern):
+                        print(
+                            f'{filename}:{i}: Merge conflict string '
+                            f'{pattern.strip().decode()!r} found',
+                        )
+                        retcode = 1
+
+    return retcode
+
+
+if __name__ == '__main__':
+    raise SystemExit(main())
diff --git a/pre_commit_hooks/check_shebang_scripts_are_executable.py b/pre_commit_hooks/check_shebang_scripts_are_executable.py
new file mode 100644
index 0000000..621696c
--- /dev/null
+++ b/pre_commit_hooks/check_shebang_scripts_are_executable.py
@@ -0,0 +1,54 @@
+"""Check that text files with a shebang are executable."""
+from __future__ import annotations
+
+import argparse
+import shlex
+import sys
+from typing import Sequence
+
+from pre_commit_hooks.check_executables_have_shebangs import EXECUTABLE_VALUES
+from pre_commit_hooks.check_executables_have_shebangs import git_ls_files
+from pre_commit_hooks.check_executables_have_shebangs import has_shebang
+
+
+def check_shebangs(paths: list[str]) -> int:
+    # Cannot optimize on non-executability here if we intend this check to
+    # work on win32 -- and that's where problems caused by non-executability
+    # (elsewhere) are most likely to arise from.
+    return _check_git_filemode(paths)
+
+
+def _check_git_filemode(paths: Sequence[str]) -> int:
+    seen: set[str] = set()
+    for ls_file in git_ls_files(paths):
+        is_executable = any(b in EXECUTABLE_VALUES for b in ls_file.mode[-3:])
+        if not is_executable and has_shebang(ls_file.filename):
+            _message(ls_file.filename)
+            seen.add(ls_file.filename)
+
+    return int(bool(seen))
+
+
+def _message(path: str) -> None:
+    print(
+        f'{path}: has a shebang but is not marked executable!\n'
+        f'  If it is supposed to be executable, try: '
+        f'`chmod +x {shlex.quote(path)}`\n'
+        f'  If on Windows, you may also need to: '
+        f'`git add --chmod=+x {shlex.quote(path)}`\n'
+        f'  If it not supposed to be executable, double-check its shebang '
+        f'is wanted.\n',
+        file=sys.stderr,
+    )
+
+
+def main(argv: Sequence[str] | None = None) -> int:
+    parser = argparse.ArgumentParser(description=__doc__)
+    parser.add_argument('filenames', nargs='*')
+    args = parser.parse_args(argv)
+
+    return check_shebangs(args.filenames)
+
+
+if __name__ == '__main__':
+    raise SystemExit(main())
diff --git a/pre_commit_hooks/check_symlinks.py b/pre_commit_hooks/check_symlinks.py
new file mode 100644
index 0000000..a85c82a
--- /dev/null
+++ b/pre_commit_hooks/check_symlinks.py
@@ -0,0 +1,27 @@
+from __future__ import annotations
+
+import argparse
+import os.path
+from typing import Sequence
+
+
+def main(argv: Sequence[str] | None = None) -> int:
+    parser = argparse.ArgumentParser(description='Checks for broken symlinks.')
+    parser.add_argument('filenames', nargs='*', help='Filenames to check')
+    args = parser.parse_args(argv)
+
+    retv = 0
+
+    for filename in args.filenames:
+        if (
+                os.path.islink(filename) and
+                not os.path.exists(filename)
+        ):  # pragma: no cover (symlink support required)
+            print(f'{filename}: Broken symlink')
+            retv = 1
+
+    return retv
+
+
+if __name__ == '__main__':
+    raise SystemExit(main())
diff --git a/pre_commit_hooks/check_toml.py b/pre_commit_hooks/check_toml.py
new file mode 100644
index 0000000..0407371
--- /dev/null
+++ b/pre_commit_hooks/check_toml.py
@@ -0,0 +1,30 @@
+from __future__ import annotations
+
+import argparse
+import sys
+from typing import Sequence
+
+if sys.version_info >= (3, 11):  # pragma: >=3.11 cover
+    import tomllib
+else:  # pragma: <3.11 cover
+    import tomli as tomllib
+
+
+def main(argv: Sequence[str] | None = None) -> int:
+    parser = argparse.ArgumentParser()
+    parser.add_argument('filenames', nargs='*', help='Filenames to check.')
+    args = parser.parse_args(argv)
+
+    retval = 0
+    for filename in args.filenames:
+        try:
+            with open(filename, mode='rb') as fp:
+                tomllib.load(fp)
+        except tomllib.TOMLDecodeError as exc:
+            print(f'{filename}: {exc}')
+            retval = 1
+    return retval
+
+
+if __name__ == '__main__':
+    raise SystemExit(main())
diff --git a/pre_commit_hooks/check_vcs_permalinks.py b/pre_commit_hooks/check_vcs_permalinks.py
new file mode 100644
index 0000000..68639bd
--- /dev/null
+++ b/pre_commit_hooks/check_vcs_permalinks.py
@@ -0,0 +1,60 @@
+from __future__ import annotations
+
+import argparse
+import re
+import sys
+from typing import Pattern
+from typing import Sequence
+
+
+def _get_pattern(domain: str) -> Pattern[bytes]:
+    regex = (
+        rf'https://{domain}/[^/ ]+/[^/ ]+/blob/'
+        r'(?![a-fA-F0-9]{4,64}/)([^/. ]+)/[^# ]+#L\d+'
+    )
+    return re.compile(regex.encode())
+
+
+def _check_filename(filename: str, patterns: list[Pattern[bytes]]) -> int:
+    retv = 0
+    with open(filename, 'rb') as f:
+        for i, line in enumerate(f, 1):
+            for pattern in patterns:
+                if pattern.search(line):
+                    sys.stdout.write(f'{filename}:{i}:')
+                    sys.stdout.flush()
+                    sys.stdout.buffer.write(line)
+                    retv = 1
+    return retv
+
+
+def main(argv: Sequence[str] | None = None) -> int:
+    parser = argparse.ArgumentParser()
+    parser.add_argument('filenames', nargs='*')
+    parser.add_argument(
+        '--additional-github-domain',
+        dest='additional_github_domains',
+        action='append',
+        default=['github.com'],
+    )
+    args = parser.parse_args(argv)
+
+    patterns = [
+        _get_pattern(domain)
+        for domain in args.additional_github_domains
+    ]
+
+    retv = 0
+
+    for filename in args.filenames:
+        retv |= _check_filename(filename, patterns)
+
+    if retv:
+        print()
+        print('Non-permanent github link detected.')
+        print('On any page on github press [y] to load a permalink.')
+    return retv
+
+
+if __name__ == '__main__':
+    raise SystemExit(main())
diff --git a/pre_commit_hooks/check_xml.py b/pre_commit_hooks/check_xml.py
new file mode 100644
index 0000000..c256af9
--- /dev/null
+++ b/pre_commit_hooks/check_xml.py
@@ -0,0 +1,26 @@
+from __future__ import annotations
+
+import argparse
+import xml.sax.handler
+from typing import Sequence
+
+
+def main(argv: Sequence[str] | None = None) -> int:
+    parser = argparse.ArgumentParser()
+    parser.add_argument('filenames', nargs='*', help='XML filenames to check.')
+    args = parser.parse_args(argv)
+
+    retval = 0
+    handler = xml.sax.handler.ContentHandler()
+    for filename in args.filenames:
+        try:
+            with open(filename, 'rb') as xml_file:
+                xml.sax.parse(xml_file, handler)
+        except xml.sax.SAXException as exc:
+            print(f'{filename}: Failed to xml parse ({exc})')
+            retval = 1
+    return retval
+
+
+if __name__ == '__main__':
+    raise SystemExit(main())
diff --git a/pre_commit_hooks/check_yaml.py b/pre_commit_hooks/check_yaml.py
new file mode 100644
index 0000000..9563347
--- /dev/null
+++ b/pre_commit_hooks/check_yaml.py
@@ -0,0 +1,72 @@
+from __future__ import annotations
+
+import argparse
+from typing import Any
+from typing import Generator
+from typing import NamedTuple
+from typing import Sequence
+
+import ruamel.yaml
+
+yaml = ruamel.yaml.YAML(typ='safe')
+
+
+def _exhaust(gen: Generator[str, None, None]) -> None:
+    for _ in gen:
+        pass
+
+
+def _parse_unsafe(*args: Any, **kwargs: Any) -> None:
+    _exhaust(yaml.parse(*args, **kwargs))
+
+
+def _load_all(*args: Any, **kwargs: Any) -> None:
+    _exhaust(yaml.load_all(*args, **kwargs))
+
+
+class Key(NamedTuple):
+    multi: bool
+    unsafe: bool
+
+
+LOAD_FNS = {
+    Key(multi=False, unsafe=False): yaml.load,
+    Key(multi=False, unsafe=True): _parse_unsafe,
+    Key(multi=True, unsafe=False): _load_all,
+    Key(multi=True, unsafe=True): _parse_unsafe,
+}
+
+
+def main(argv: Sequence[str] | None = None) -> int:
+    parser = argparse.ArgumentParser()
+    parser.add_argument(
+        '-m', '--multi', '--allow-multiple-documents', action='store_true',
+    )
+    parser.add_argument(
+        '--unsafe', action='store_true',
+        help=(
+            'Instead of loading the files, simply parse them for syntax.  '
+            'A syntax-only check enables extensions and unsafe constructs '
+            'which would otherwise be forbidden.  Using this option removes '
+            'all guarantees of portability to other yaml implementations.  '
+            'Implies --allow-multiple-documents'
+        ),
+    )
+    parser.add_argument('filenames', nargs='*', help='Filenames to check.')
+    args = parser.parse_args(argv)
+
+    load_fn = LOAD_FNS[Key(multi=args.multi, unsafe=args.unsafe)]
+
+    retval = 0
+    for filename in args.filenames:
+        try:
+            with open(filename, encoding='UTF-8') as f:
+                load_fn(f)
+        except ruamel.yaml.YAMLError as exc:
+            print(exc)
+            retval = 1
+    return retval
+
+
+if __name__ == '__main__':
+    raise SystemExit(main())
diff --git a/pre_commit_hooks/debug_statement_hook.py b/pre_commit_hooks/debug_statement_hook.py
new file mode 100644
index 0000000..cf544c7
--- /dev/null
+++ b/pre_commit_hooks/debug_statement_hook.py
@@ -0,0 +1,86 @@
+from __future__ import annotations
+
+import argparse
+import ast
+import traceback
+from typing import NamedTuple
+from typing import Sequence
+
+
+DEBUG_STATEMENTS = {
+    'bpdb',
+    'ipdb',
+    'pdb',
+    'pdbr',
+    'pudb',
+    'pydevd_pycharm',
+    'q',
+    'rdb',
+    'rpdb',
+    'wdb',
+}
+
+
+class Debug(NamedTuple):
+    line: int
+    col: int
+    name: str
+    reason: str
+
+
+class DebugStatementParser(ast.NodeVisitor):
+    def __init__(self) -> None:
+        self.breakpoints: list[Debug] = []
+
+    def visit_Import(self, node: ast.Import) -> None:
+        for name in node.names:
+            if name.name in DEBUG_STATEMENTS:
+                st = Debug(node.lineno, node.col_offset, name.name, 'imported')
+                self.breakpoints.append(st)
+
+    def visit_ImportFrom(self, node: ast.ImportFrom) -> None:
+        if node.module in DEBUG_STATEMENTS:
+            st = Debug(node.lineno, node.col_offset, node.module, 'imported')
+            self.breakpoints.append(st)
+
+    def visit_Call(self, node: ast.Call) -> None:
+        """python3.7+ breakpoint()"""
+        if isinstance(node.func, ast.Name) and node.func.id == 'breakpoint':
+            st = Debug(node.lineno, node.col_offset, node.func.id, 'called')
+            self.breakpoints.append(st)
+        self.generic_visit(node)
+
+
+def check_file(filename: str) -> int:
+    try:
+        with open(filename, 'rb') as f:
+            ast_obj = ast.parse(f.read(), filename=filename)
+    except SyntaxError:
+        print(f'{filename} - Could not parse ast')
+        print()
+        print('\t' + traceback.format_exc().replace('\n', '\n\t'))
+        print()
+        return 1
+
+    visitor = DebugStatementParser()
+    visitor.visit(ast_obj)
+
+    for bp in visitor.breakpoints:
+        print(f'{filename}:{bp.line}:{bp.col}: {bp.name} {bp.reason}')
+
+    return int(bool(visitor.breakpoints))
+
+
+def main(argv: Sequence[str] | None = None) -> int:
+    parser = argparse.ArgumentParser()
+    parser.add_argument('filenames', nargs='*', help='Filenames to run')
+    args = parser.parse_args(argv)
+
+    retv = 0
+    for filename in args.filenames:
+        retv |= check_file(filename)
+    return retv
+
+
+if __name__ == '__main__':
+    raise SystemExit(main())
diff --git a/pre_commit_hooks/destroyed_symlinks.py b/pre_commit_hooks/destroyed_symlinks.py
new file mode 100644
index 0000000..f256908
--- /dev/null
+++ b/pre_commit_hooks/destroyed_symlinks.py
@@ -0,0 +1,92 @@
+from __future__ import annotations
+
+import argparse
+import shlex
+import subprocess
+from typing import Sequence
+
+from pre_commit_hooks.util import cmd_output
+from pre_commit_hooks.util import zsplit
+
+ORDINARY_CHANGED_ENTRIES_MARKER = '1'
+PERMS_LINK = '120000'
+PERMS_NONEXIST = '000000'
+
+
+def find_destroyed_symlinks(files: Sequence[str]) -> list[str]:
+    destroyed_links: list[str] = []
+    if not files:
+        return destroyed_links
+    for line in zsplit(
+        cmd_output('git', 'status', '--porcelain=v2', '-z', '--', *files),
+    ):
+        splitted = line.split(' ')
+        if splitted and splitted[0] == ORDINARY_CHANGED_ENTRIES_MARKER:
+            # https://git-scm.com/docs/git-status#_changed_tracked_entries
+            (
+                _, _, _,
+                mode_HEAD,
+                mode_index,
+                _,
+                hash_HEAD,
+                hash_index,
+                *path_splitted,
+            ) = splitted
+            path = ' '.join(path_splitted)
+            if (
+                    mode_HEAD == PERMS_LINK and
+                    mode_index != PERMS_LINK and
+                    mode_index != PERMS_NONEXIST
+            ):
+                if hash_HEAD == hash_index:
+                    # if old and new hashes are equal, it's not needed to check
+                    # anything more, we've found a destroyed symlink for sure
+                    destroyed_links.append(path)
+                else:
+                    # if old and new hashes are *not* equal, it doesn't mean
+                    # that everything is OK - new file may be altered
+                    # by something like trailing-whitespace and/or
+                    # mixed-line-ending hooks so we need to go deeper
+                    SIZE_CMD = ('git', 'cat-file', '-s')
+                    size_index = int(cmd_output(*SIZE_CMD, hash_index).strip())
+                    size_HEAD = int(cmd_output(*SIZE_CMD, hash_HEAD).strip())
+
+                    # in the worst case new file may have CRLF added
+                    # so check content only if new file is bigger
+                    # not more than 2 bytes compared to the old one
+                    if size_index <= size_HEAD + 2:
+                        head_content = subprocess.check_output(
+                            ('git', 'cat-file', '-p', hash_HEAD),
+                        ).rstrip()
+                        index_content = subprocess.check_output(
+                            ('git', 'cat-file', '-p', hash_index),
+                        ).rstrip()
+                        if head_content == index_content:
+                            destroyed_links.append(path)
+    return destroyed_links
+
+
+def main(argv: Sequence[str] | None = None) -> int:
+    parser = argparse.ArgumentParser()
+    parser.add_argument('filenames', nargs='*', help='Filenames to check.')
+    args = parser.parse_args(argv)
+    destroyed_links = find_destroyed_symlinks(files=args.filenames)
+    if destroyed_links:
+        print('Destroyed symlinks:')
+        for destroyed_link in destroyed_links:
+            print(f'- {destroyed_link}')
+        print('You should unstage affected files:')
+        print(f'\tgit reset HEAD -- {shlex.join(destroyed_links)}')
+        print(
+            'And retry commit. As a long term solution '
+            'you may try to explicitly tell git that your '
+            'environment does not support symlinks:',
+        )
+        print('\tgit config core.symlinks false')
+        return 1
+    else:
+        return 0
+
+
+if __name__ == '__main__':
+    raise SystemExit(main())
diff --git a/pre_commit_hooks/detect_aws_credentials.py b/pre_commit_hooks/detect_aws_credentials.py
new file mode 100644
index 0000000..4f59d9c
--- /dev/null
+++ b/pre_commit_hooks/detect_aws_credentials.py
@@ -0,0 +1,151 @@
+from __future__ import annotations
+
+import argparse
+import configparser
+import os
+from typing import NamedTuple
+from typing import Sequence
+
+
+class BadFile(NamedTuple):
+    filename: str
+    key: str
+
+
+def get_aws_cred_files_from_env() -> set[str]:
+    """Extract credential file paths from environment variables."""
+    return {
+        os.environ[env_var]
+        for env_var in (
+            'AWS_CONFIG_FILE', 'AWS_CREDENTIAL_FILE',
+            'AWS_SHARED_CREDENTIALS_FILE', 'BOTO_CONFIG',
+        )
+        if env_var in os.environ
+    }
+
+
+def get_aws_secrets_from_env() -> set[str]:
+    """Extract AWS secrets from environment variables."""
+    keys = set()
+    for env_var in (
+        'AWS_SECRET_ACCESS_KEY', 'AWS_SECURITY_TOKEN', 'AWS_SESSION_TOKEN',
+    ):
+        if os.environ.get(env_var):
+            keys.add(os.environ[env_var])
+    return keys
+
+
+def get_aws_secrets_from_file(credentials_file: str) -> set[str]:
+    """Extract AWS secrets from configuration files.
+
+    Read an ini-style configuration file and return a set with all found AWS
+    secret access keys.
+    """
+    aws_credentials_file_path = os.path.expanduser(credentials_file)
+    if not os.path.exists(aws_credentials_file_path):
+        return set()
+
+    parser = configparser.ConfigParser()
+    try:
+        parser.read(aws_credentials_file_path)
+    except configparser.MissingSectionHeaderError:
+        return set()
+
+    keys = set()
+    for section in parser.sections():
+        for var in (
+            'aws_secret_access_key', 'aws_security_token',
+            'aws_session_token',
+        ):
+            try:
+                key = parser.get(section, var).strip()
+                if key:
+                    keys.add(key)
+            except configparser.NoOptionError:
+                pass
+    return keys
+
+
+def check_file_for_aws_keys(
+        filenames: Sequence[str],
+        keys: set[bytes],
+) -> list[BadFile]:
+    """Check if files contain AWS secrets.
+
+    Return a list of all files containing AWS secrets and keys found, with all
+    but the first four characters obfuscated to ease debugging.
+    """
+    bad_files = []
+
+    for filename in filenames:
+        with open(filename, 'rb') as content:
+            text_body = content.read()
+            for key in keys:
+                # naively match the entire file, low chance of incorrect
+                # collision
+                if key in text_body:
+                    key_hidden = key.decode()[:4].ljust(28, '*')
+                    bad_files.append(BadFile(filename, key_hidden))
+    return bad_files
+
+
+def main(argv: Sequence[str] | None = None) -> int:
+    parser = argparse.ArgumentParser()
+    parser.add_argument('filenames', nargs='+', help='Filenames to run')
+    parser.add_argument(
+        '--credentials-file',
+        dest='credentials_file',
+        action='append',
+        default=[
+            '~/.aws/config', '~/.aws/credentials', '/etc/boto.cfg', '~/.boto',
+        ],
+        help=(
+            'Location of additional AWS credential file from which to get '
+            'secret keys. Can be passed multiple times.'
+        ),
+    )
+    parser.add_argument(
+        '--allow-missing-credentials',
+        dest='allow_missing_credentials',
+        action='store_true',
+        help='Allow hook to pass when no credentials are detected.',
+    )
+    args = parser.parse_args(argv)
+
+    credential_files = set(args.credentials_file)
+
+    # Add the credentials files configured via environment variables to the set
+    # of files to to gather AWS secrets from.
+    credential_files |= get_aws_cred_files_from_env()
+
+    keys: set[str] = set()
+    for credential_file in credential_files:
+        keys |= get_aws_secrets_from_file(credential_file)
+
+    # Secrets might be part of environment variables, so add such secrets to
+    # the set of keys.
+    keys |= get_aws_secrets_from_env()
+
+    if not keys and args.allow_missing_credentials:
+        return 0
+
+    if not keys:
+        print(
+            'No AWS keys were found in the configured credential files and '
+            'environment variables.\nPlease ensure you have the correct '
+            'setting for --credentials-file',
+        )
+        return 2
+
+    keys_b = {key.encode() for key in keys}
+    bad_filenames = check_file_for_aws_keys(args.filenames, keys_b)
+    if bad_filenames:
+        for bad_file in bad_filenames:
+            print(f'AWS secret found in {bad_file.filename}: {bad_file.key}')
+        return 1
+    else:
+        return 0
+
+
+if __name__ == '__main__':
+    raise SystemExit(main())
diff --git a/pre_commit_hooks/detect_private_key.py b/pre_commit_hooks/detect_private_key.py
new file mode 100644
index 0000000..cd51f90
--- /dev/null
+++ b/pre_commit_hooks/detect_private_key.py
@@ -0,0 +1,42 @@
+from __future__ import annotations
+
+import argparse
+from typing import Sequence
+
+BLACKLIST = [
+    b'BEGIN RSA PRIVATE KEY',
+    b'BEGIN DSA PRIVATE KEY',
+    b'BEGIN EC PRIVATE KEY',
+    b'BEGIN OPENSSH PRIVATE KEY',
+    b'BEGIN PRIVATE KEY',
+    b'PuTTY-User-Key-File-2',
+    b'BEGIN SSH2 ENCRYPTED PRIVATE KEY',
+    b'BEGIN PGP PRIVATE KEY BLOCK',
+    b'BEGIN ENCRYPTED PRIVATE KEY',
+    b'BEGIN OpenVPN Static key V1',
+]
+
+
+def main(argv: Sequence[str] | None = None) -> int:
+    parser = argparse.ArgumentParser()
+    parser.add_argument('filenames', nargs='*', help='Filenames to check')
+    args = parser.parse_args(argv)
+
+    private_key_files = []
+
+    for filename in args.filenames:
+        with open(filename, 'rb') as f:
+            content = f.read()
+            if any(line in content for line in BLACKLIST):
+                private_key_files.append(filename)
+
+    if private_key_files:
+        for private_key_file in private_key_files:
+            print(f'Private key found: {private_key_file}')
+        return 1
+    else:
+        return 0
+
+
+if __name__ == '__main__':
+    raise SystemExit(main())
diff --git a/pre_commit_hooks/end_of_file_fixer.py b/pre_commit_hooks/end_of_file_fixer.py
new file mode 100644
index 0000000..a30dce9
--- /dev/null
+++ b/pre_commit_hooks/end_of_file_fixer.py
@@ -0,0 +1,71 @@
+from __future__ import annotations
+
+import argparse
+import os
+from typing import IO
+from typing import Sequence
+
+
+def fix_file(file_obj: IO[bytes]) -> int:
+    # Test for newline at end of file
+    # Empty files will throw IOError here
+    try:
+        file_obj.seek(-1, os.SEEK_END)
+    except OSError:
+        return 0
+    last_character = file_obj.read(1)
+    # last_character will be '' for an empty file
+    if last_character not in {b'\n', b'\r'} and last_character != b'':
+        # Needs this seek for windows, otherwise IOError
+        file_obj.seek(0, os.SEEK_END)
+        file_obj.write(b'\n')
+        return 1
+
+    while last_character in {b'\n', b'\r'}:
+        # Deal with the beginning of the file
+        if file_obj.tell() == 1:
+            # If we've reached the beginning of the file and it is all
+            # linebreaks then we can make this file empty
+            file_obj.seek(0)
+            file_obj.truncate()
+            return 1
+
+        # Go back two bytes and read a character
+        file_obj.seek(-2, os.SEEK_CUR)
+        last_character = file_obj.read(1)
+
+    # Our current position is at the end of the file just before any amount of
+    # newlines.  If we find extraneous newlines, then backtrack and trim them.
+    position = file_obj.tell()
+    remaining = file_obj.read()
+    for sequence in (b'\n', b'\r\n', b'\r'):
+        if remaining == sequence:
+            return 0
+        elif remaining.startswith(sequence):
+            file_obj.seek(position + len(sequence))
+            file_obj.truncate()
+            return 1
+
+    return 0
+
+
+def main(argv: Sequence[str] | None = None) -> int:
+    parser = argparse.ArgumentParser()
+    parser.add_argument('filenames', nargs='*', help='Filenames to fix')
+    args = parser.parse_args(argv)
+
+    retv = 0
+
+    for filename in args.filenames:
+        # Read as binary so we can read byte-by-byte
+        with open(filename, 'rb+') as file_obj:
+            ret_for_file = fix_file(file_obj)
+            if ret_for_file:
+                print(f'Fixing {filename}')
+            retv |= ret_for_file
+
+    return retv
+
+
+if __name__ == '__main__':
+    raise SystemExit(main())
diff --git a/pre_commit_hooks/file_contents_sorter.py b/pre_commit_hooks/file_contents_sorter.py
new file mode 100644
index 0000000..02bdbcc
--- /dev/null
+++ b/pre_commit_hooks/file_contents_sorter.py
@@ -0,0 +1,88 @@
+"""
+A very simple pre-commit hook that, when passed one or more filenames
+as arguments, will sort the lines in those files.
+
+An example use case for this: you have a deploy-allowlist.txt file
+in a repo that contains a list of filenames that is used to specify
+files to be included in a docker container. This file has one filename
+per line. Various users are adding/removing lines from this file; using
+this hook on that file should reduce the instances of git merge
+conflicts and keep the file nicely ordered.
+"""
+from __future__ import annotations
+
+import argparse
+from typing import Any
+from typing import Callable
+from typing import IO
+from typing import Iterable
+from typing import Sequence
+
+PASS = 0
+FAIL = 1
+
+
+def sort_file_contents(
+    f: IO[bytes],
+    key: Callable[[bytes], Any] | None,
+    *,
+    unique: bool = False,
+) -> int:
+    before = list(f)
+    lines: Iterable[bytes] = (
+        line.rstrip(b'\n\r') for line in before if line.strip()
+    )
+    if unique:
+        lines = set(lines)
+    after = sorted(lines, key=key)
+
+    before_string = b''.join(before)
+    after_string = b'\n'.join(after)
+
+    if after_string:
+        after_string += b'\n'
+
+    if before_string == after_string:
+        return PASS
+    else:
+        f.seek(0)
+        f.write(after_string)
+        f.truncate()
+        return FAIL
+
+
+def main(argv: Sequence[str] | None = None) -> int:
+    parser = argparse.ArgumentParser()
+    parser.add_argument('filenames', nargs='+', help='Files to sort')
+    parser.add_argument(
+        '--ignore-case',
+        action='store_const',
+        const=bytes.lower,
+        default=None,
+        help='fold lower case to upper case characters',
+    )
+    parser.add_argument(
+        '--unique',
+        action='store_true',
+        help='ensure each line is unique',
+    )
+    args = parser.parse_args(argv)
+
+    retv = PASS
+
+    for arg in args.filenames:
+        with open(arg, 'rb+') as file_obj:
+            ret_for_file = sort_file_contents(
+                file_obj, key=args.ignore_case, unique=args.unique,
+            )
+
+            if ret_for_file:
+                print(f'Sorting {arg}')
+
+            retv |= ret_for_file
+
+    return retv
+
+
+if __name__ == '__main__':
+    raise SystemExit(main())
diff --git a/pre_commit_hooks/fix_byte_order_marker.py b/pre_commit_hooks/fix_byte_order_marker.py
new file mode 100644
index 0000000..22a4990
--- /dev/null
+++ b/pre_commit_hooks/fix_byte_order_marker.py
@@ -0,0 +1,31 @@
+from __future__ import annotations
+
+import argparse
+from typing import Sequence
+
+
+def main(argv: Sequence[str] | None = None) -> int:
+    parser = argparse.ArgumentParser()
+    parser.add_argument('filenames', nargs='*', help='Filenames to check')
+    args = parser.parse_args(argv)
+
+    retv = 0
+
+    for filename in args.filenames:
+        with open(filename, 'rb') as f_b:
+            bts = f_b.read(3)
+
+        if bts == b'\xef\xbb\xbf':
+            with open(filename, newline='', encoding='utf-8-sig') as f:
+                contents = f.read()
+            with open(filename, 'w', newline='', encoding='utf-8') as f:
+                f.write(contents)
+
+            print(f'{filename}: removed byte-order marker')
+            retv = 1
+
+    return retv
+
+
+if __name__ == '__main__':
+    raise SystemExit(main())
diff --git a/pre_commit_hooks/fix_encoding_pragma.py b/pre_commit_hooks/fix_encoding_pragma.py
new file mode 100644
index 0000000..60c71ee
--- /dev/null
+++ b/pre_commit_hooks/fix_encoding_pragma.py
@@ -0,0 +1,149 @@
+from __future__ import annotations
+
+import argparse
+from typing import IO
+from typing import NamedTuple
+from typing import Sequence
+
+DEFAULT_PRAGMA = b'# -*- coding: utf-8 -*-'
+
+
+def has_coding(line: bytes) -> bool:
+    if not line.strip():
+        return False
+    return (
+        line.lstrip()[:1] == b'#' and (
+            b'unicode' in line or
+            b'encoding' in line or
+            b'coding:' in line or
+            b'coding=' in line
+        )
+    )
+
+
+class ExpectedContents(NamedTuple):
+    shebang: bytes
+    rest: bytes
+    # True: has exactly the coding pragma expected
+    # False: missing coding pragma entirely
+    # None: has a coding pragma, but it does not match
+    pragma_status: bool | None
+    ending: bytes
+
+    @property
+    def has_any_pragma(self) -> bool:
+        return self.pragma_status is not False
+
+    def is_expected_pragma(self, remove: bool) -> bool:
+        expected_pragma_status = not remove
+        return self.pragma_status is expected_pragma_status
+
+
+def _get_expected_contents(
+        first_line: bytes,
+        second_line: bytes,
+        rest: bytes,
+        expected_pragma: bytes,
+) -> ExpectedContents:
+    ending = b'\r\n' if first_line.endswith(b'\r\n') else b'\n'
+
+    if first_line.startswith(b'#!'):
+        shebang = first_line
+        potential_coding = second_line
+    else:
+        shebang = b''
+        potential_coding = first_line
+        rest = second_line + rest
+
+    if potential_coding.rstrip(b'\r\n') == expected_pragma:
+        pragma_status: bool | None = True
+    elif has_coding(potential_coding):
+        pragma_status = None
+    else:
+        pragma_status = False
+        rest = potential_coding + rest
+
+    return ExpectedContents(
+        shebang=shebang, rest=rest, pragma_status=pragma_status, ending=ending,
+    )
+
+
+def fix_encoding_pragma(
+        f: IO[bytes],
+        remove: bool = False,
+        expected_pragma: bytes = DEFAULT_PRAGMA,
+) -> int:
+    expected = _get_expected_contents(
+        f.readline(), f.readline(), f.read(), expected_pragma,
+    )
+
+    # Special cases for empty files
+    if not expected.rest.strip():
+        # If a file only has a shebang or a coding pragma, remove it
+        if expected.has_any_pragma or expected.shebang:
+            f.seek(0)
+            f.truncate()
+            f.write(b'')
+            return 1
+        else:
+            return 0
+
+    if expected.is_expected_pragma(remove):
+        return 0
+
+    # Otherwise, write out the new file
+    f.seek(0)
+    f.truncate()
+    f.write(expected.shebang)
+    if not remove:
+        f.write(expected_pragma + expected.ending)
+    f.write(expected.rest)
+
+    return 1
+
+
+def _normalize_pragma(pragma: str) -> bytes:
+    return pragma.encode().rstrip()
+
+
+def main(argv: Sequence[str] | None = None) -> int:
+    parser = argparse.ArgumentParser(
+        'Fixes the encoding pragma of python files',
+    )
+    parser.add_argument('filenames', nargs='*', help='Filenames to fix')
+    parser.add_argument(
+        '--pragma', default=DEFAULT_PRAGMA, type=_normalize_pragma,
+        help=(
+            f'The encoding pragma to use.  '
+            f'Default: {DEFAULT_PRAGMA.decode()}'
+        ),
+    )
+    parser.add_argument(
+        '--remove', action='store_true',
+        help='Remove the encoding pragma (Useful in a python3-only codebase)',
+    )
+    args = parser.parse_args(argv)
+
+    retv = 0
+
+    if args.remove:
+        fmt = 'Removed encoding pragma from {filename}'
+    else:
+        fmt = 'Added `{pragma}` to {filename}'
+
+    for filename in args.filenames:
+        with open(filename, 'r+b') as f:
+            file_ret = fix_encoding_pragma(
+                f, remove=args.remove, expected_pragma=args.pragma,
+            )
+            retv |= file_ret
+            if file_ret:
+                print(
+                    fmt.format(pragma=args.pragma.decode(), filename=filename),
+                )
+
+    return retv
+
+
+if __name__ == '__main__':
+    raise SystemExit(main())
diff --git a/pre_commit_hooks/forbid_new_submodules.py b/pre_commit_hooks/forbid_new_submodules.py
new file mode 100644
index 0000000..b806cad
--- /dev/null
+++ b/pre_commit_hooks/forbid_new_submodules.py
@@ -0,0 +1,48 @@
+from __future__ import annotations
+
+import argparse
+import os
+from typing import Sequence
+
+from pre_commit_hooks.util import cmd_output
+
+
+def main(argv: Sequence[str] | None = None) -> int:
+    parser = argparse.ArgumentParser()
+    parser.add_argument('filenames', nargs='*')
+    args = parser.parse_args(argv)
+
+    if (
+        'PRE_COMMIT_FROM_REF' in os.environ and
+        'PRE_COMMIT_TO_REF' in os.environ
+    ):
+        diff_arg = '...'.join((
+            os.environ['PRE_COMMIT_FROM_REF'],
+            os.environ['PRE_COMMIT_TO_REF'],
+        ))
+    else:
+        diff_arg = '--staged'
+    added_diff = cmd_output(
+        'git', 'diff', '--diff-filter=A', '--raw', diff_arg, '--',
+        *args.filenames,
+    )
+    retv = 0
+    for line in added_diff.splitlines():
+        metadata, filename = line.split('\t', 1)
+        new_mode = metadata.split(' ')[1]
+        if new_mode == '160000':
+            print(f'{filename}: new submodule introduced')
+            retv = 1
+
+    if retv:
+        print()
+        print('This commit introduces new submodules.')
+        print('Did you unintentionally `git add .`?')
+        print('To fix: git rm {thesubmodule}  # no trailing slash')
+        print('Also check .gitmodules')
+
+    return retv
+
+
+if __name__ == '__main__':
+    raise SystemExit(main())
diff --git a/pre_commit_hooks/mixed_line_ending.py b/pre_commit_hooks/mixed_line_ending.py
new file mode 100644
index 0000000..0328e86
--- /dev/null
+++ b/pre_commit_hooks/mixed_line_ending.py
@@ -0,0 +1,88 @@
+from __future__ import annotations
+
+import argparse
+import collections
+from typing import Sequence
+
+
+CRLF = b'\r\n'
+LF = b'\n'
+CR = b'\r'
+# Prefer LF to CRLF to CR, but detect CRLF before LF
+ALL_ENDINGS = (CR, CRLF, LF)
+FIX_TO_LINE_ENDING = {'cr': CR, 'crlf': CRLF, 'lf': LF}
+
+
+def _fix(filename: str, contents: bytes, ending: bytes) -> None:
+    new_contents = b''.join(
+        line.rstrip(b'\r\n') + ending for line in contents.splitlines(True)
+    )
+    with open(filename, 'wb') as f:
+        f.write(new_contents)
+
+
+def fix_filename(filename: str, fix: str) -> int:
+    with open(filename, 'rb') as f:
+        contents = f.read()
+
+    counts: dict[bytes, int] = collections.defaultdict(int)
+
+    for line in contents.splitlines(True):
+        for ending in ALL_ENDINGS:
+            if line.endswith(ending):
+                counts[ending] += 1
+                break
+
+    # Some amount of mixed line endings
+    mixed = sum(bool(x) for x in counts.values()) > 1
+
+    if fix == 'no' or (fix == 'auto' and not mixed):
+        return mixed
+
+    if fix == 'auto':
+        max_ending = LF
+        max_lines = 0
+        # ordering is important here such that lf > crlf > cr
+        for ending_type in ALL_ENDINGS:
+            # also important, using >= to find a max that prefers the last
+            if counts[ending_type] >= max_lines:
+                max_ending = ending_type
+                max_lines = counts[ending_type]
+
+        _fix(filename, contents, max_ending)
+        return 1
+    else:
+        target_ending = FIX_TO_LINE_ENDING[fix]
+        # find if there are lines with *other* endings
+        # It's possible there's no line endings of the target type
+        counts.pop(target_ending, None)
+        other_endings = bool(sum(counts.values()))
+        if other_endings:
+            _fix(filename, contents, target_ending)
+        return other_endings
+
+
+def main(argv: Sequence[str] | None = None) -> int:
+    parser = argparse.ArgumentParser()
+    parser.add_argument(
+        '-f', '--fix',
+        choices=('auto', 'no') + tuple(FIX_TO_LINE_ENDING),
+        default='auto',
+        help='Replace line ending with the specified. Default is "auto"',
+    )
+    parser.add_argument('filenames', nargs='*', help='Filenames to fix')
+    args = parser.parse_args(argv)
+
+    retv = 0
+    for filename in args.filenames:
+        if fix_filename(filename, args.fix):
+            if args.fix == 'no':
+                print(f'{filename}: mixed line endings')
+            else:
+                print(f'{filename}: fixed mixed line endings')
+            retv = 1
+    return retv
+
+
+if __name__ == '__main__':
+    raise SystemExit(main())
diff --git a/pre_commit_hooks/no_commit_to_branch.py b/pre_commit_hooks/no_commit_to_branch.py
new file mode 100644
index 0000000..741f726
--- /dev/null
+++ b/pre_commit_hooks/no_commit_to_branch.py
@@ -0,0 +1,48 @@
+from __future__ import annotations
+
+import argparse
+import re
+from typing import AbstractSet
+from typing import Sequence
+
+from pre_commit_hooks.util import CalledProcessError
+from pre_commit_hooks.util import cmd_output
+
+
+def is_on_branch(
+        protected: AbstractSet[str],
+        patterns: AbstractSet[str] = frozenset(),
+) -> bool:
+    try:
+        ref_name = cmd_output('git', 'symbolic-ref', 'HEAD')
+    except CalledProcessError:
+        return False
+    chunks = ref_name.strip().split('/')
+    branch_name = '/'.join(chunks[2:])
+    return branch_name in protected or any(
+        re.match(p, branch_name) for p in patterns
+    )
+
+
+def main(argv: Sequence[str] | None = None) -> int:
+    parser = argparse.ArgumentParser()
+    parser.add_argument(
+        '-b', '--branch', action='append',
+        help='branch to disallow commits to, may be specified multiple times',
+    )
+    parser.add_argument(
+        '-p', '--pattern', action='append',
+        help=(
+            'regex pattern for branch name to disallow commits to, '
+            'may be specified multiple times'
+        ),
+    )
+    args = parser.parse_args(argv)
+
+    protected = frozenset(args.branch or ('master', 'main'))
+    patterns = frozenset(args.pattern or ())
+    return int(is_on_branch(protected, patterns))
+
+
+if __name__ == '__main__':
+    raise SystemExit(main())
diff --git a/pre_commit_hooks/pretty_format_json.py b/pre_commit_hooks/pretty_format_json.py
new file mode 100644
index 0000000..627a11c
--- /dev/null
+++ b/pre_commit_hooks/pretty_format_json.py
@@ -0,0 +1,133 @@
+from __future__ import annotations
+
+import argparse
+import json
+import sys
+from difflib import unified_diff
+from typing import Mapping
+from typing import Sequence
+
+
+def _get_pretty_format(
+        contents: str,
+        indent: str,
+        ensure_ascii: bool = True,
+        sort_keys: bool = True,
+        top_keys: Sequence[str] = (),
+) -> str:
+    def pairs_first(pairs: Sequence[tuple[str, str]]) -> Mapping[str, str]:
+        before = [pair for pair in pairs if pair[0] in top_keys]
+        before = sorted(before, key=lambda x: top_keys.index(x[0]))
+        after = [pair for pair in pairs if pair[0] not in top_keys]
+        if sort_keys:
+            after.sort()
+        return dict(before + after)
+    json_pretty = json.dumps(
+        json.loads(contents, object_pairs_hook=pairs_first),
+        indent=indent,
+        ensure_ascii=ensure_ascii,
+    )
+    return f'{json_pretty}\n'
+
+
+def _autofix(filename: str, new_contents: str) -> None:
+    print(f'Fixing file {filename}')
+    with open(filename, 'w', encoding='UTF-8') as f:
+        f.write(new_contents)
+
+
+def parse_num_to_int(s: str) -> int | str:
+    """Convert string numbers to int, leaving strings as is."""
+    try:
+        return int(s)
+    except ValueError:
+        return s
+
+
+def parse_topkeys(s: str) -> list[str]:
+    return s.split(',')
+
+
+def get_diff(source: str, target: str, file: str) -> str:
+    source_lines = source.splitlines(True)
+    target_lines = target.splitlines(True)
+    diff = unified_diff(source_lines, target_lines, fromfile=file, tofile=file)
+    return ''.join(diff)
+
+
+def main(argv: Sequence[str] | None = None) -> int:
+    parser = argparse.ArgumentParser()
+    parser.add_argument(
+        '--autofix',
+        action='store_true',
+        dest='autofix',
+        help='Automatically fixes encountered not-pretty-formatted files',
+    )
+    parser.add_argument(
+        '--indent',
+        type=parse_num_to_int,
+        default='2',
+        help=(
+            'The number of indent spaces or a string to be used as delimiter'
+            ' for indentation level e.g. 4 or "\t" (Default: 2)'
+        ),
+    )
+    parser.add_argument(
+        '--no-ensure-ascii',
+        action='store_true',
+        dest='no_ensure_ascii',
+        default=False,
+        help=(
+            'Do NOT convert non-ASCII characters to Unicode escape sequences '
+            '(\\uXXXX)'
+        ),
+    )
+    parser.add_argument(
+        '--no-sort-keys',
+        action='store_true',
+        dest='no_sort_keys',
+        default=False,
+        help='Keep JSON nodes in the same order',
+    )
+    parser.add_argument(
+        '--top-keys',
+        type=parse_topkeys,
+        dest='top_keys',
+        default=[],
+        help='Ordered list of keys to keep at the top of JSON hashes',
+    )
+    parser.add_argument('filenames', nargs='*', help='Filenames to fix')
+    args = parser.parse_args(argv)
+
+    status = 0
+
+    for json_file in args.filenames:
+        with open(json_file, encoding='UTF-8') as f:
+            contents = f.read()
+
+        try:
+            pretty_contents = _get_pretty_format(
+                contents, args.indent, ensure_ascii=not args.no_ensure_ascii,
+                sort_keys=not args.no_sort_keys, top_keys=args.top_keys,
+            )
+        except ValueError:
+            print(
+                f'Input File {json_file} is not a valid JSON, consider using '
+                f'check-json',
+            )
+            return 1
+
+        if contents != pretty_contents:
+            if args.autofix:
+                _autofix(json_file, pretty_contents)
+            else:
+                diff_output = get_diff(contents, pretty_contents, json_file)
+                sys.stdout.buffer.write(diff_output.encode())
+
+            status = 1
+
+    return status
+
+
+if __name__ == '__main__':
+    raise SystemExit(main())
diff --git a/pre_commit_hooks/removed.py b/pre_commit_hooks/removed.py
new file mode 100644
index 0000000..6f6c7b7
--- /dev/null
+++ b/pre_commit_hooks/removed.py
@@ -0,0 +1,16 @@
+from __future__ import annotations
+
+import sys
+from typing import Sequence
+
+
+def main(argv: Sequence[str] | None = None) -> int:
+    argv = argv if argv is not None else sys.argv[1:]
+    hookid, new_hookid, url = argv[:3]
+    raise SystemExit(
+        f'`{hookid}` has been removed -- use `{new_hookid}` from {url}',
+    )
+
+
+if __name__ == '__main__':
+    raise SystemExit(main())
diff --git a/pre_commit_hooks/requirements_txt_fixer.py b/pre_commit_hooks/requirements_txt_fixer.py
new file mode 100644
index 0000000..5884394
--- /dev/null
+++ b/pre_commit_hooks/requirements_txt_fixer.py
@@ -0,0 +1,153 @@
+from __future__ import annotations
+
+import argparse
+import re
+from typing import IO
+from typing import Sequence
+
+
+PASS = 0
+FAIL = 1
+
+
+class Requirement:
+    UNTIL_COMPARISON = re.compile(b'={2,3}|!=|~=|>=?|<=?')
+    UNTIL_SEP = re.compile(rb'[^;\s]+')
+
+    def __init__(self) -> None:
+        self.value: bytes | None = None
+        self.comments: list[bytes] = []
+
+    @property
+    def name(self) -> bytes:
+        assert self.value is not None, self.value
+        name = self.value.lower()
+        for egg in (b'#egg=', b'&egg='):
+            if egg in self.value:
+                return name.partition(egg)[-1]
+
+        m = self.UNTIL_SEP.match(name)
+        assert m is not None
+
+        name = m.group()
+        m = self.UNTIL_COMPARISON.search(name)
+        if not m:
+            return name
+
+        return name[:m.start()]
+
+    def __lt__(self, requirement: Requirement) -> bool:
+        # \n means top of file comment, so always return True,
+        # otherwise just do a string comparison with value.
+        assert self.value is not None, self.value
+        if self.value == b'\n':
+            return True
+        elif requirement.value == b'\n':
+            return False
+        else:
+            return self.name < requirement.name
+
+    def is_complete(self) -> bool:
+        return (
+            self.value is not None and
+            not self.value.rstrip(b'\r\n').endswith(b'\\')
+        )
+
+    def append_value(self, value: bytes) -> None:
+        if self.value is not None:
+            self.value += value
+        else:
+            self.value = value
+
+
+def fix_requirements(f: IO[bytes]) -> int:
+    requirements: list[Requirement] = []
+    before = list(f)
+    after: list[bytes] = []
+
+    before_string = b''.join(before)
+
+    # adds new line in case one is missing
+    # AND a change to the requirements file is needed regardless:
+    if before and not before[-1].endswith(b'\n'):
+        before[-1] += b'\n'
+
+    # If the file is empty (i.e. only whitespace/newlines) exit early
+    if before_string.strip() == b'':
+        return PASS
+
+    for line in before:
+        # If the most recent requirement object has a value, then it's
+        # time to start building the next requirement object.
+
+        if not len(requirements) or requirements[-1].is_complete():
+            requirements.append(Requirement())
+
+        requirement = requirements[-1]
+
+        # If we see a newline before any requirements, then this is a
+        # top of file comment.
+        if len(requirements) == 1 and line.strip() == b'':
+            if (
+                    len(requirement.comments) and
+                    requirement.comments[0].startswith(b'#')
+            ):
+                requirement.value = b'\n'
+            else:
+                requirement.comments.append(line)
+        elif line.lstrip().startswith(b'#') or line.strip() == b'':
+            requirement.comments.append(line)
+        else:
+            requirement.append_value(line)
+
+    # if a file ends in a comment, preserve it at the end
+    if requirements[-1].value is None:
+        rest = requirements.pop().comments
+    else:
+        rest = []
+
+    # find and remove pkg-resources==0.0.0
+    # which is automatically added by broken pip package under Debian
+    requirements = [
+        req for req in requirements
+        if req.value != b'pkg-resources==0.0.0\n'
+    ]
+
+    for requirement in sorted(requirements):
+        after.extend(requirement.comments)
+        assert requirement.value, requirement.value
+        after.append(requirement.value)
+    after.extend(rest)
+
+    after_string = b''.join(after)
+
+    if before_string == after_string:
+        return PASS
+    else:
+        f.seek(0)
+        f.write(after_string)
+        f.truncate()
+        return FAIL
+
+
+def main(argv: Sequence[str] | None = None) -> int:
+    parser = argparse.ArgumentParser()
+    parser.add_argument('filenames', nargs='*', help='Filenames to fix')
+    args = parser.parse_args(argv)
+
+    retv = PASS
+
+    for arg in args.filenames:
+        with open(arg, 'rb+') as file_obj:
+            ret_for_file = fix_requirements(file_obj)
+
+            if ret_for_file:
+                print(f'Sorting {arg}')
+
+            retv |= ret_for_file
+
+    return retv
+
+
+if __name__ == '__main__':
+    raise SystemExit(main())
diff --git a/pre_commit_hooks/sort_simple_yaml.py b/pre_commit_hooks/sort_simple_yaml.py
new file mode 100644
index 0000000..116b5c1
--- /dev/null
+++ b/pre_commit_hooks/sort_simple_yaml.py
@@ -0,0 +1,125 @@
+"""Sort a simple YAML file, keeping blocks of comments and definitions
+together.
+
+We assume a strict subset of YAML that looks like:
+
+    # block of header comments
+    # here that should always
+    # be at the top of the file
+
+    # optional comments
+    # can go here
+    key: value
+    key: value
+
+    key: value
+
+In other words, we don't sort deeper than the top layer, and might corrupt
+complicated YAML files.
+"""
+from __future__ import annotations
+
+import argparse
+from typing import Sequence
+
+
+QUOTES = ["'", '"']
+
+
+def sort(lines: list[str]) -> list[str]:
+    """Sort a YAML file in alphabetical order, keeping blocks together.
+
+    :param lines: array of strings (without newlines)
+    :return: sorted array of strings
+    """
+    # make a copy of lines since we will clobber it
+    lines = list(lines)
+    new_lines = parse_block(lines, header=True)
+
+    for block in sorted(parse_blocks(lines), key=first_key):
+        if new_lines:
+            new_lines.append('')
+        new_lines.extend(block)
+
+    return new_lines
+
+
+def parse_block(lines: list[str], header: bool = False) -> list[str]:
+    """Parse and return a single block, popping off the start of `lines`.
+
+    If parsing a header block, we stop after we reach a line that is not a
+    comment. Otherwise, we stop after reaching an empty line.
+
+    :param lines: list of lines
+    :param header: whether we are parsing a header block
+    :return: list of lines that form the single block
+    """
+    block_lines = []
+    while lines and lines[0] and (not header or lines[0].startswith('#')):
+        block_lines.append(lines.pop(0))
+    return block_lines
+
+
+def parse_blocks(lines: list[str]) -> list[list[str]]:
+    """Parse and return all possible blocks, popping off the start of `lines`.
+
+    :param lines: list of lines
+    :return: list of blocks, where each block is a list of lines
+    """
+    blocks = []
+
+    while lines:
+        if lines[0] == '':
+            lines.pop(0)
+        else:
+            blocks.append(parse_block(lines))
+
+    return blocks
+
+
+def first_key(lines: list[str]) -> str:
+    """Returns a string representing the sort key of a block.
+
+    The sort key is the first YAML key we encounter, ignoring comments, and
+    stripping leading quotes.
+
+    >>> print(test)
+    # some comment
+    'foo': true
+    >>> first_key(test)
+    'foo'
+    """
+    for line in lines:
+        if line.startswith('#'):
+            continue
+        if any(line.startswith(quote) for quote in QUOTES):
+            return line[1:]
+        return line
+    else:
+        return ''  # not actually reached in reality
+
+
+def main(argv: Sequence[str] | None = None) -> int:
+    parser = argparse.ArgumentParser()
+    parser.add_argument('filenames', nargs='*', help='Filenames to fix')
+    args = parser.parse_args(argv)
+
+    retval = 0
+
+    for filename in args.filenames:
+        with open(filename, 'r+') as f:
+            lines = [line.rstrip() for line in f.readlines()]
+            new_lines = sort(lines)
+
+            if lines != new_lines:
+                print(f'Fixing file `{filename}`')
+                f.seek(0)
+                f.write('\n'.join(new_lines) + '\n')
+                f.truncate()
+                retval = 1
+
+    return retval
+
+
+if __name__ == '__main__':
+    raise SystemExit(main())
diff --git a/pre_commit_hooks/string_fixer.py b/pre_commit_hooks/string_fixer.py
new file mode 100644
index 0000000..d1b1c4a
--- /dev/null
+++ b/pre_commit_hooks/string_fixer.py
@@ -0,0 +1,93 @@
+from __future__ import annotations
+
+import argparse
+import io
+import re
+import sys
+import tokenize
+from typing import Sequence
+
+if sys.version_info >= (3, 12):  # pragma: >=3.12 cover
+    FSTRING_START = tokenize.FSTRING_START
+    FSTRING_END = tokenize.FSTRING_END
+else:  # pragma: <3.12 cover
+    FSTRING_START = FSTRING_END = -1
+
+START_QUOTE_RE = re.compile('^[a-zA-Z]*"')
+
+
+def handle_match(token_text: str) -> str:
+    if '"""' in token_text or "'''" in token_text:
+        return token_text
+
+    match = START_QUOTE_RE.match(token_text)
+    if match is not None:
+        meat = token_text[match.end():-1]
+        if '"' in meat or "'" in meat:
+            return token_text
+        else:
+            return match.group().replace('"', "'") + meat + "'"
+    else:
+        return token_text
+
+
+def get_line_offsets_by_line_no(src: str) -> list[int]:
+    # Padded so we can index with line number
+    offsets = [-1, 0]
+    for line in src.splitlines(True):
+        offsets.append(offsets[-1] + len(line))
+    return offsets
+
+
+def fix_strings(filename: str) -> int:
+    with open(filename, encoding='UTF-8', newline='') as f:
+        contents = f.read()
+    line_offsets = get_line_offsets_by_line_no(contents)
+
+    # Basically a mutable string
+    splitcontents = list(contents)
+
+    fstring_depth = 0
+
+    # Iterate in reverse so the offsets are always correct
+    tokens_l = list(tokenize.generate_tokens(io.StringIO(contents).readline))
+    tokens = reversed(tokens_l)
+    for token_type, token_text, (srow, scol), (erow, ecol), _ in tokens:
+        if token_type == FSTRING_START:  # pragma: >=3.12 cover
+            fstring_depth += 1
+        elif token_type == FSTRING_END:  # pragma: >=3.12 cover
+            fstring_depth -= 1
+        elif fstring_depth == 0 and token_type == tokenize.STRING:
+            new_text = handle_match(token_text)
+            splitcontents[
+                line_offsets[srow] + scol:
+                line_offsets[erow] + ecol
+            ] = new_text
+
+    new_contents = ''.join(splitcontents)
+    if contents != new_contents:
+        with open(filename, 'w', encoding='UTF-8', newline='') as f:
+            f.write(new_contents)
+        return 1
+    else:
+        return 0
+
+
+def main(argv: Sequence[str] | None = None) -> int:
+    parser = argparse.ArgumentParser()
+    parser.add_argument('filenames', nargs='*', help='Filenames to fix')
+    args = parser.parse_args(argv)
+
+    retv = 0
+
+    for filename in args.filenames:
+        return_value = fix_strings(filename)
+        if return_value != 0:
+            print(f'Fixing strings in {filename}')
+        retv |= return_value
+
+    return retv
+
+
+if __name__ == '__main__':
+    raise SystemExit(main())
diff --git a/pre_commit_hooks/tests_should_end_in_test.py b/pre_commit_hooks/tests_should_end_in_test.py
new file mode 100644
index 0000000..e7842af
--- /dev/null
+++ b/pre_commit_hooks/tests_should_end_in_test.py
@@ -0,0 +1,53 @@
+from __future__ import annotations
+
+import argparse
+import os.path
+import re
+from typing import Sequence
+
+
+def main(argv: Sequence[str] | None = None) -> int:
+    parser = argparse.ArgumentParser()
+    parser.add_argument('filenames', nargs='*')
+    mutex = parser.add_mutually_exclusive_group()
+    mutex.add_argument(
+        '--pytest',
+        dest='pattern',
+        action='store_const',
+        const=r'.*_test\.py',
+        default=r'.*_test\.py',
+        help='(the default) ensure tests match %(const)s',
+    )
+    mutex.add_argument(
+        '--pytest-test-first',
+        dest='pattern',
+        action='store_const',
+        const=r'test_.*\.py',
+        help='ensure tests match %(const)s',
+    )
+    mutex.add_argument(
+        '--django', '--unittest',
+        dest='pattern',
+        action='store_const',
+        const=r'test.*\.py',
+        help='ensure tests match %(const)s',
+    )
+    args = parser.parse_args(argv)
+
+    retcode = 0
+    reg = re.compile(args.pattern)
+    for filename in args.filenames:
+        base = os.path.basename(filename)
+        if (
+                not reg.fullmatch(base) and
+                not base == '__init__.py' and
+                not base == 'conftest.py'
+        ):
+            retcode = 1
+            print(f'{filename} does not match pattern "{args.pattern}"')
+
+    return retcode
+
+
+if __name__ == '__main__':
+    raise SystemExit(main())
diff --git a/pre_commit_hooks/trailing_whitespace_fixer.py b/pre_commit_hooks/trailing_whitespace_fixer.py
new file mode 100644
index 0000000..84f5067
--- /dev/null
+++ b/pre_commit_hooks/trailing_whitespace_fixer.py
@@ -0,0 +1,103 @@
+from __future__ import annotations
+
+import argparse
+import os
+from typing import Sequence
+
+
+def _fix_file(
+        filename: str,
+        is_markdown: bool,
+        chars: bytes | None,
+) -> bool:
+    with open(filename, mode='rb') as file_processed:
+        lines = file_processed.readlines()
+    newlines = [_process_line(line, is_markdown, chars) for line in lines]
+    if newlines != lines:
+        with open(filename, mode='wb') as file_processed:
+            for line in newlines:
+                file_processed.write(line)
+        return True
+    else:
+        return False
+
+
+def _process_line(
+        line: bytes,
+        is_markdown: bool,
+        chars: bytes | None,
+) -> bytes:
+    if line[-2:] == b'\r\n':
+        eol = b'\r\n'
+        line = line[:-2]
+    elif line[-1:] == b'\n':
+        eol = b'\n'
+        line = line[:-1]
+    else:
+        eol = b''
+    # preserve trailing two-space for non-blank lines in markdown files
+    if is_markdown and (not line.isspace()) and line.endswith(b'  '):
+        return line[:-2].rstrip(chars) + b'  ' + eol
+    return line.rstrip(chars) + eol
+
+
+def main(argv: Sequence[str] | None = None) -> int:
+    parser = argparse.ArgumentParser()
+    parser.add_argument(
+        '--no-markdown-linebreak-ext',
+        action='store_true',
+        help=argparse.SUPPRESS,
+    )
+    parser.add_argument(
+        '--markdown-linebreak-ext',
+        action='append',
+        default=[],
+        metavar='*|EXT[,EXT,...]',
+        help=(
+            'Markdown extensions (or *) to not strip linebreak spaces.  '
+            'default: %(default)s'
+        ),
+    )
+    parser.add_argument(
+        '--chars',
+        help=(
+            'The set of characters to strip from the end of lines.  '
+            'Defaults to all whitespace characters.'
+        ),
+    )
+    parser.add_argument('filenames', nargs='*', help='Filenames to fix')
+    args = parser.parse_args(argv)
+
+    if args.no_markdown_linebreak_ext:
+        print('--no-markdown-linebreak-ext now does nothing!')
+
+    md_args = args.markdown_linebreak_ext
+    if '' in md_args:
+        parser.error('--markdown-linebreak-ext requires a non-empty argument')
+    all_markdown = '*' in md_args
+    # normalize extensions; split at ',', lowercase, and force 1 leading '.'
+    md_exts = [
+        '.' + x.lower().lstrip('.') for x in ','.join(md_args).split(',')
+    ]
+
+    # reject probable "eaten" filename as extension: skip leading '.' with [1:]
+    for ext in md_exts:
+        if any(c in ext[1:] for c in r'./\:'):
+            parser.error(
+                f'bad --markdown-linebreak-ext extension '
+                f'{ext!r} (has . / \\ :)\n'
+                f"  (probably filename; use '--markdown-linebreak-ext=EXT')",
+            )
+    chars = None if args.chars is None else args.chars.encode()
+    return_code = 0
+    for filename in args.filenames:
+        _, extension = os.path.splitext(filename.lower())
+        md = all_markdown or extension in md_exts
+        if _fix_file(filename, md, chars):
+            print(f'Fixing {filename}')
+            return_code = 1
+    return return_code
+
+
+if __name__ == '__main__':
+    raise SystemExit(main())
diff --git a/pre_commit_hooks/util.py b/pre_commit_hooks/util.py
new file mode 100644
index 0000000..d6c90ae
--- /dev/null
+++ b/pre_commit_hooks/util.py
@@ -0,0 +1,32 @@
+from __future__ import annotations
+
+import subprocess
+from typing import Any
+
+
+class CalledProcessError(RuntimeError):
+    pass
+
+
+def added_files() -> set[str]:
+    cmd = ('git', 'diff', '--staged', '--name-only', '--diff-filter=A')
+    return set(cmd_output(*cmd).splitlines())
+
+
+def cmd_output(*cmd: str, retcode: int | None = 0, **kwargs: Any) -> str:
+    kwargs.setdefault('stdout', subprocess.PIPE)
+    kwargs.setdefault('stderr', subprocess.PIPE)
+    proc = subprocess.Popen(cmd, **kwargs)
+    stdout, stderr = proc.communicate()
+    stdout = stdout.decode()
+    if retcode is not None and proc.returncode != retcode:
+        raise CalledProcessError(cmd, retcode, proc.returncode, stdout, stderr)
+    return stdout
+
+
+def zsplit(s: str) -> list[str]:
+    s = s.strip('\0')
+    if s:
+        return s.split('\0')
+    else:
+        return []