1 files changed, 81 insertions, 0 deletions
diff --git a/pre_commit/error_handler.py b/pre_commit/error_handler.py
new file mode 100644
index 0000000..73e608b
--- /dev/null
+++ b/pre_commit/error_handler.py
@@ -0,0 +1,81 @@
+from __future__ import annotations
+
+import contextlib
+import functools
+import os.path
+import sys
+import traceback
+from collections.abc import Generator
+from typing import IO
+
+import pre_commit.constants as C
+from pre_commit import output
+from pre_commit.errors import FatalError
+from pre_commit.store import Store
+from pre_commit.util import cmd_output_b
+from pre_commit.util import force_bytes
+
+
+def _log_and_exit(
+    msg: str,
+    ret_code: int,
+    exc: BaseException,
+    formatted: str,
+) -> None:
+    error_msg = f'{msg}: {type(exc).__name__}: '.encode() + force_bytes(exc)
+    output.write_line_b(error_msg)
+
+    _, git_version_b, _ = cmd_output_b('git', '--version', check=False)
+    git_version = git_version_b.decode(errors='backslashreplace').rstrip()
+
+    storedir = Store().directory
+    log_path = os.path.join(storedir, 'pre-commit.log')
+    with contextlib.ExitStack() as ctx:
+        if os.access(storedir, os.W_OK):
+            output.write_line(f'Check the log at {log_path}')
+            log: IO[bytes] = ctx.enter_context(open(log_path, 'wb'))
+        else:  # pragma: win32 no cover
+            output.write_line(f'Failed to write to log at {log_path}')
+            log = sys.stdout.buffer
+
+        _log_line = functools.partial(output.write_line, stream=log)
+        _log_line_b = functools.partial(output.write_line_b, stream=log)
+
+        _log_line('### version information')
+        _log_line()
+        _log_line('```')
+        _log_line(f'pre-commit version: {C.VERSION}')
+        _log_line(f'git --version: {git_version}')
+        _log_line('sys.version:')
+        for line in sys.version.splitlines():
+            _log_line(f'    {line}')
+        _log_line(f'sys.executable: {sys.executable}')
+        _log_line(f'os.name: {os.name}')
+        _log_line(f'sys.platform: {sys.platform}')
+        _log_line('```')
+        _log_line()
+
+        _log_line('### error information')
+        _log_line()
+        _log_line('```')
+        _log_line_b(error_msg)
+        _log_line('```')
+        _log_line()
+        _log_line('```')
+        _log_line(formatted.rstrip())
+        _log_line('```')
+    raise SystemExit(ret_code)
+
+
+@contextlib.contextmanager
+def error_handler() -> Generator[None, None, None]:
+    try:
+        yield
+    except (Exception, KeyboardInterrupt) as e:
+        if isinstance(e, FatalError):
+            msg, ret_code = 'An error has occurred', 1
+        elif isinstance(e, KeyboardInterrupt):
+            msg, ret_code = 'Interrupted (^C)', 130
+        else:
+            msg, ret_code = 'An unexpected error has occurred', 3
+        _log_and_exit(msg, ret_code, e, traceback.format_exc())