1 files changed, 25 insertions, 50 deletions

diff --git a/sphinx/util/osutil.py b/sphinx/util/osutil.py
index 2b3fe51b0..3751fcc08 100644
--- a/sphinx/util/osutil.py
+++ b/sphinx/util/osutil.py
@@ -19,14 +19,11 @@ import time
 import warnings
 from io import StringIO
 from os import path
+from typing import Any, Generator, Iterator, List, Tuple, Type
 
 from sphinx.deprecation import RemovedInSphinx30Warning, RemovedInSphinx40Warning
 from sphinx.testing.path import path as Path
 
-if False:
-    # For type annotation
-    from typing import Any, Iterator, List, Tuple  # NOQA
-
 # Errnos that we need.
 EEXIST = getattr(errno, 'EEXIST', 0)  # RemovedInSphinx40Warning
 ENOENT = getattr(errno, 'ENOENT', 0)  # RemovedInSphinx40Warning
@@ -41,19 +38,16 @@ EINVAL = getattr(errno, 'EINVAL', 0)  # RemovedInSphinx40Warning
 SEP = "/"
 
 
-def os_path(canonicalpath):
-    # type: (str) -> str
+def os_path(canonicalpath: str) -> str:
     return canonicalpath.replace(SEP, path.sep)
 
 
-def canon_path(nativepath):
-    # type: (str) -> str
+def canon_path(nativepath: str) -> str:
     """Return path in OS-independent form"""
     return nativepath.replace(path.sep, SEP)
 
 
-def relative_uri(base, to):
-    # type: (str, str) -> str
+def relative_uri(base: str, to: str) -> str:
     """Return a relative URL from ``base`` to ``to``."""
     if to.startswith(SEP):
         return to
@@ -76,22 +70,19 @@ def relative_uri(base, to):
     return ('..' + SEP) * (len(b2) - 1) + SEP.join(t2)
 
 
-def ensuredir(path):
-    # type: (str) -> None
+def ensuredir(path: str) -> None:
     """Ensure that a path exists."""
     os.makedirs(path, exist_ok=True)
 
 
-def walk(top, topdown=True, followlinks=False):
-    # type: (str, bool, bool) -> Iterator[Tuple[str, List[str], List[str]]]
+def walk(top: str, topdown: bool = True, followlinks: bool = False) -> Iterator[Tuple[str, List[str], List[str]]]:  # NOQA
     warnings.warn('sphinx.util.osutil.walk() is deprecated for removal. '
                   'Please use os.walk() instead.',
                   RemovedInSphinx40Warning)
     return os.walk(top, topdown=topdown, followlinks=followlinks)
 
 
-def mtimes_of_files(dirnames, suffix):
-    # type: (List[str], str) -> Iterator[float]
+def mtimes_of_files(dirnames: List[str], suffix: str) -> Iterator[float]:
     for dirname in dirnames:
         for root, dirs, files in os.walk(dirname):
             for sfile in files:
@@ -102,8 +93,7 @@ def mtimes_of_files(dirnames, suffix):
                         pass
 
 
-def movefile(source, dest):
-    # type: (str, str) -> None
+def movefile(source: str, dest: str) -> None:
     """Move a file, removing the destination if it exists."""
     if os.path.exists(dest):
         try:
@@ -113,16 +103,14 @@ def movefile(source, dest):
     os.rename(source, dest)
 
 
-def copytimes(source, dest):
-    # type: (str, str) -> None
+def copytimes(source: str, dest: str) -> None:
     """Copy a file's modification times."""
     st = os.stat(source)
     if hasattr(os, 'utime'):
         os.utime(dest, (st.st_atime, st.st_mtime))
 
 
-def copyfile(source, dest):
-    # type: (str, str) -> None
+def copyfile(source: str, dest: str) -> None:
     """Copy a file and its modification times, if possible.
 
     Note: ``copyfile`` skips copying if the file has not been changed"""
@@ -139,18 +127,15 @@ no_fn_re = re.compile(r'[^a-zA-Z0-9_-]')
 project_suffix_re = re.compile(' Documentation$')
 
 
-def make_filename(string):
-    # type: (str) -> str
+def make_filename(string: str) -> str:
     return no_fn_re.sub('', string) or 'sphinx'
 
 
-def make_filename_from_project(project):
-    # type: (str) -> str
+def make_filename_from_project(project: str) -> str:
     return make_filename(project_suffix_re.sub('', project)).lower()
 
 
-def ustrftime(format, *args):
-    # type: (str, Any) -> str
+def ustrftime(format: str, *args) -> str:
     """[DEPRECATED] strftime for unicode strings."""
     warnings.warn('sphinx.util.osutil.ustrtime is deprecated for removal',
                   RemovedInSphinx30Warning, stacklevel=2)
@@ -171,8 +156,7 @@ def ustrftime(format, *args):
         return r.encode().decode('unicode-escape')
 
 
-def relpath(path, start=os.curdir):
-    # type: (str, str) -> str
+def relpath(path: str, start: str = os.curdir) -> str:
     """Return a relative filepath to *path* either from the current directory or
     from an optional *start* directory.
 
@@ -189,8 +173,7 @@ safe_relpath = relpath  # for compatibility
 fs_encoding = sys.getfilesystemencoding() or sys.getdefaultencoding()
 
 
-def abspath(pathdir):
-    # type: (str) -> str
+def abspath(pathdir: str) -> str:
     if isinstance(pathdir, Path):
         return pathdir.abspath()
     else:
@@ -205,8 +188,7 @@ def abspath(pathdir):
         return pathdir
 
 
-def getcwd():
-    # type: () -> str
+def getcwd() -> str:
     warnings.warn('sphinx.util.osutil.getcwd() is deprecated. '
                   'Please use os.getcwd() instead.',
                   RemovedInSphinx40Warning)
@@ -214,8 +196,7 @@ def getcwd():
 
 
 @contextlib.contextmanager
-def cd(target_dir):
-    # type: (str) -> Iterator[None]
+def cd(target_dir: str) -> Generator[None, None, None]:
     cwd = os.getcwd()
     try:
         os.chdir(target_dir)
@@ -236,19 +217,16 @@ class FileAvoidWrite:
 
     Objects can be used as context managers.
     """
-    def __init__(self, path):
-        # type: (str) -> None
+    def __init__(self, path: str) -> None:
         self._path = path
         self._io = None  # type: StringIO
 
-    def write(self, data):
-        # type: (str) -> None
+    def write(self, data: str) -> None:
         if not self._io:
             self._io = StringIO()
         self._io.write(data)
 
-    def close(self):
-        # type: () -> None
+    def close(self) -> None:
         """Stop accepting writes and write file, if needed."""
         if not self._io:
             raise Exception('FileAvoidWrite does not support empty files.')
@@ -267,16 +245,14 @@ class FileAvoidWrite:
         with open(self._path, 'w') as f:
             f.write(buf)
 
-    def __enter__(self):
-        # type: () -> FileAvoidWrite
+    def __enter__(self) -> "FileAvoidWrite":
         return self
 
-    def __exit__(self, type, value, traceback):
-        # type: (str, str, str) -> None
+    def __exit__(self, exc_type: Type[Exception], exc_value: Exception, traceback: Any) -> bool:  # NOQA
         self.close()
+        return True
 
-    def __getattr__(self, name):
-        # type: (str) -> Any
+    def __getattr__(self, name: str) -> Any:
         # Proxy to _io instance.
         if not self._io:
             raise Exception('Must write to FileAvoidWrite before other '
@@ -285,8 +261,7 @@ class FileAvoidWrite:
         return getattr(self._io, name)
 
 
-def rmtree(path):
-    # type: (str) -> None
+def rmtree(path: str) -> None:
     if os.path.isdir(path):
         shutil.rmtree(path)
     else: