Add: post-rewrite hook support

pre_commit/commands/hook_impl.py

@@ -78,6 +78,7 @@ def _ns(
         commit_msg_filename: Optional[str] = None,
         checkout_type: Optional[str] = None,
         is_squash_merge: Optional[str] = None,
+        rewrite_command: Optional[str] = None,
 ) -> argparse.Namespace:
     return argparse.Namespace(
         color=color,
@@ -92,6 +93,7 @@ def _ns(
         all_files=all_files,
         checkout_type=checkout_type,
         is_squash_merge=is_squash_merge,
+        rewrite_command=rewrite_command,
         files=(),
         hook=None,
         verbose=False,
@@ -166,6 +168,7 @@ _EXPECTED_ARG_LENGTH_BY_HOOK = {
     'pre-commit': 0,
     'pre-merge-commit': 0,
     'post-merge': 1,
+    'post-rewrite': 1,
     'pre-push': 2,
 }
 
@@ -209,6 +212,8 @@ def _run_ns(
         )
     elif hook_type == 'post-merge':
         return _ns(hook_type, color, is_squash_merge=args[0])
+    elif hook_type == 'post-rewrite':
+        return _ns(hook_type, color, rewrite_command=args[0])
     else:
         raise AssertionError(f'unexpected hook type: {hook_type}')
 

pre_commit/commands/run.py

@@ -245,7 +245,9 @@ def _compute_cols(hooks: Sequence[Hook]) -> int:
 
 def _all_filenames(args: argparse.Namespace) -> Collection[str]:
     # these hooks do not operate on files
-    if args.hook_stage in {'post-checkout', 'post-commit', 'post-merge'}:
+    if args.hook_stage in {
+        'post-checkout', 'post-commit', 'post-merge', 'post-rewrite',
+    }:
         return ()
     elif args.hook_stage in {'prepare-commit-msg', 'commit-msg'}:
         return (args.commit_msg_filename,)
@@ -386,6 +388,9 @@ def run(
     if args.is_squash_merge:
         environ['PRE_COMMIT_IS_SQUASH_MERGE'] = args.is_squash_merge
 
+    if args.rewrite_command:
+        environ['PRE_COMMIT_REWRITE_COMMAND'] = args.rewrite_command
+
     # Set pre_commit flag
     environ['PRE_COMMIT'] = '1'
 

pre_commit/constants.py

@@ -19,6 +19,7 @@ VERSION = importlib_metadata.version('pre_commit')
 STAGES = (
     'commit', 'merge-commit', 'prepare-commit-msg', 'commit-msg',
     'post-commit', 'manual', 'post-checkout', 'push', 'post-merge',
+    'post-rewrite',
 )
 
 DEFAULT = 'default'

pre_commit/main.py

@@ -69,6 +69,7 @@ def _add_hook_type_option(parser: argparse.ArgumentParser) -> None:
         '-t', '--hook-type', choices=(
             'pre-commit', 'pre-merge-commit', 'pre-push', 'prepare-commit-msg',
             'commit-msg', 'post-commit', 'post-checkout', 'post-merge',
+            'post-rewrite',
         ),
         action=AppendReplaceDefault,
         default=['pre-commit'],
@@ -146,6 +147,13 @@ def _add_run_options(parser: argparse.ArgumentParser) -> None:
             'squash merge'
         ),
     )
+    parser.add_argument(
+        '--rewrite-command',
+        help=(
+            'During a post-rewrite hook, specifies the command that invoked '
+            'the rewrite'
+        ),
+    )
 
 
 def _adjust_args_and_chdir(args: argparse.Namespace) -> None: