Allow arbitrary bytes in output. Resolves #245

pre_commit/commands/run.py

@@ -102,8 +102,9 @@ def _run_single_hook(hook, repo, args, write, skips=frozenset()):
         write('hookid: {0}\n'.format(hook['id']))
         write('\n')
         for output in (stdout, stderr):
+            assert type(output) is bytes, type(output)
             if output.strip():
-                write(output.strip() + '\n')
+                write(output.strip() + b'\n')
         write('\n')
 
     return retcode

pre_commit/languages/helpers.py

@@ -22,6 +22,7 @@ def run_hook(env, hook, file_args):
         ' '.join(['xargs', '-0', '-s4000', hook['entry']] + quoted_args),
         stdin=file_args_to_stdin(file_args),
         retcode=None,
+        encoding=None,
     )
 
 

pre_commit/languages/pcre.py

@@ -24,4 +24,5 @@ def run_hook(repo_cmd_runner, hook, file_args):
         ],
         stdin=file_args_to_stdin(file_args),
         retcode=None,
+        encoding=None,
     )

pre_commit/languages/script.py

@@ -17,4 +17,5 @@ def run_hook(repo_cmd_runner, hook, file_args):
         # TODO: this is duplicated in pre_commit/languages/helpers.py
         stdin=file_args_to_stdin(file_args),
         retcode=None,
+        encoding=None,
     )

pre_commit/languages/system.py

@@ -18,4 +18,5 @@ def run_hook(repo_cmd_runner, hook, file_args):
         ['xargs', '-0'] + shlex.split(hook['entry']) + hook['args'],
         stdin=file_args_to_stdin(file_args),
         retcode=None,
+        encoding=None,
     )