Add types to pre-commit

pre_commit/git.py

@@ -1,15 +1,20 @@
 import logging
 import os.path
 import sys
+from typing import Dict
+from typing import List
+from typing import Optional
+from typing import Set
 
 from pre_commit.util import cmd_output
 from pre_commit.util import cmd_output_b
+from pre_commit.util import EnvironT
 
 
 logger = logging.getLogger(__name__)
 
 
-def zsplit(s):
+def zsplit(s: str) -> List[str]:
     s = s.strip('\0')
     if s:
         return s.split('\0')
@@ -17,7 +22,7 @@ def zsplit(s):
         return []
 
 
-def no_git_env(_env=None):
+def no_git_env(_env: Optional[EnvironT] = None) -> Dict[str, str]:
     # Too many bugs dealing with environment variables and GIT:
     # https://github.com/pre-commit/pre-commit/issues/300
     # In git 2.6.3 (maybe others), git exports GIT_WORK_TREE while running
@@ -34,11 +39,11 @@ def no_git_env(_env=None):
     }
 
 
-def get_root():
+def get_root() -> str:
     return cmd_output('git', 'rev-parse', '--show-toplevel')[1].strip()
 
 
-def get_git_dir(git_root='.'):
+def get_git_dir(git_root: str = '.') -> str:
     opts = ('--git-common-dir', '--git-dir')
     _, out, _ = cmd_output('git', 'rev-parse', *opts, cwd=git_root)
     for line, opt in zip(out.splitlines(), opts):
@@ -48,12 +53,12 @@ def get_git_dir(git_root='.'):
         raise AssertionError('unreachable: no git dir')
 
 
-def get_remote_url(git_root):
+def get_remote_url(git_root: str) -> str:
     _, out, _ = cmd_output('git', 'config', 'remote.origin.url', cwd=git_root)
     return out.strip()
 
 
-def is_in_merge_conflict():
+def is_in_merge_conflict() -> bool:
     git_dir = get_git_dir('.')
     return (
         os.path.exists(os.path.join(git_dir, 'MERGE_MSG')) and
@@ -61,7 +66,7 @@ def is_in_merge_conflict():
     )
 
 
-def parse_merge_msg_for_conflicts(merge_msg):
+def parse_merge_msg_for_conflicts(merge_msg: bytes) -> List[str]:
     # Conflicted files start with tabs
     return [
         line.lstrip(b'#').strip().decode('UTF-8')
@@ -71,7 +76,7 @@ def parse_merge_msg_for_conflicts(merge_msg):
     ]
 
 
-def get_conflicted_files():
+def get_conflicted_files() -> Set[str]:
     logger.info('Checking merge-conflict files only.')
     # Need to get the conflicted files from the MERGE_MSG because they could
     # have resolved the conflict by choosing one side or the other
@@ -92,7 +97,7 @@ def get_conflicted_files():
     return set(merge_conflict_filenames) | set(merge_diff_filenames)
 
 
-def get_staged_files(cwd=None):
+def get_staged_files(cwd: Optional[str] = None) -> List[str]:
     return zsplit(
         cmd_output(
             'git', 'diff', '--staged', '--name-only', '--no-ext-diff', '-z',
@@ -103,7 +108,7 @@ def get_staged_files(cwd=None):
     )
 
 
-def intent_to_add_files():
+def intent_to_add_files() -> List[str]:
     _, stdout, _ = cmd_output('git', 'status', '--porcelain', '-z')
     parts = list(reversed(zsplit(stdout)))
     intent_to_add = []
@@ -117,11 +122,11 @@ def intent_to_add_files():
     return intent_to_add
 
 
-def get_all_files():
+def get_all_files() -> List[str]:
     return zsplit(cmd_output('git', 'ls-files', '-z')[1])
 
 
-def get_changed_files(new, old):
+def get_changed_files(new: str, old: str) -> List[str]:
     return zsplit(
         cmd_output(
             'git', 'diff', '--name-only', '--no-ext-diff', '-z',
@@ -130,24 +135,22 @@ def get_changed_files(new, old):
     )
 
 
-def head_rev(remote):
+def head_rev(remote: str) -> str:
     _, out, _ = cmd_output('git', 'ls-remote', '--exit-code', remote, 'HEAD')
     return out.split()[0]
 
 
-def has_diff(*args, **kwargs):
-    repo = kwargs.pop('repo', '.')
-    assert not kwargs, kwargs
+def has_diff(*args: str, repo: str = '.') -> bool:
     cmd = ('git', 'diff', '--quiet', '--no-ext-diff') + args
     return cmd_output_b(*cmd, cwd=repo, retcode=None)[0] == 1
 
 
-def has_core_hookpaths_set():
+def has_core_hookpaths_set() -> bool:
     _, out, _ = cmd_output_b('git', 'config', 'core.hooksPath', retcode=None)
     return bool(out.strip())
 
 
-def init_repo(path, remote):
+def init_repo(path: str, remote: str) -> None:
     if os.path.isdir(remote):
         remote = os.path.abspath(remote)
 
@@ -156,7 +159,7 @@ def init_repo(path, remote):
     cmd_output_b('git', 'remote', 'add', 'origin', remote, cwd=path, env=env)
 
 
-def commit(repo='.'):
+def commit(repo: str = '.') -> None:
     env = no_git_env()
     name, email = 'pre-commit', 'asottile+pre-commit@umich.edu'
     env['GIT_AUTHOR_NAME'] = env['GIT_COMMITTER_NAME'] = name
@@ -165,12 +168,12 @@ def commit(repo='.'):
     cmd_output_b(*cmd, cwd=repo, env=env)
 
 
-def git_path(name, repo='.'):
+def git_path(name: str, repo: str = '.') -> str:
     _, out, _ = cmd_output('git', 'rev-parse', '--git-path', name, cwd=repo)
     return os.path.join(repo, out.strip())
 
 
-def check_for_cygwin_mismatch():
+def check_for_cygwin_mismatch() -> None:
     """See https://github.com/pre-commit/pre-commit/issues/354"""
     if sys.platform in ('cygwin', 'win32'):  # pragma: no cover (windows)
         is_cygwin_python = sys.platform == 'cygwin'