Prepend hook name to each output line

pre_commit/clientlib.py

@@ -79,6 +79,7 @@ MANIFEST_HOOK_DICT = cfgv.Map(
     cfgv.Optional('require_serial', cfgv.check_bool, False),
     cfgv.Optional('stages', cfgv.check_array(cfgv.check_one_of(C.STAGES)), []),
     cfgv.Optional('verbose', cfgv.check_bool, False),
+    cfgv.Optional('prepend_name', cfgv.check_bool, False),
 )
 MANIFEST_SCHEMA = cfgv.Array(MANIFEST_HOOK_DICT)
 

pre_commit/commands/run.py

@@ -218,9 +218,19 @@ def _run_single_hook(
         if files_modified:
             _subtle_line('- files were modified by this hook', use_color)
 
-        if out.strip():
+        hook_output = out.strip()
+        if hook_output:
+            if hook.prepend_name:
+                # Prepends the hook name to each line of its console output
+                hook_output = b'\n'.join(
+                    [
+                        bytes(f'{hook.name}: ', encoding='utf8') + line
+                        for line in hook_output.split(b'\n')
+                    ],
+                )
+
             output.write_line()
-            output.write_line_b(out.strip(), logfile_name=hook.log_file)
+            output.write_line_b(hook_output, logfile_name=hook.log_file)
             output.write_line()
 
     return files_modified or bool(retcode), diff_after

pre_commit/hook.py

@@ -35,6 +35,7 @@ class Hook(NamedTuple):
     minimum_pre_commit_version: str
     require_serial: bool
     stages: Sequence[str]
+    prepend_name: bool
     verbose: bool
 
     @property

tests/repository_test.py

@@ -1005,6 +1005,7 @@ def test_manifest_hooks(tempdir_factory, store):
         types_or=[],
         verbose=False,
         fail_fast=False,
+        prepend_name=False,
     )