typing: add type hints to the platform specific scm modules

Surprisingly, pytype struggled to figure out the return types in the posix
functions.

mercurial/scmposix.py

@@ -1,95 +1,103 b''
 import array
 import errno
 import fcntl
 import os
 import sys
 
+from typing import (
+    List,
+    Tuple,
+)
+
 from .pycompat import getattr
 from . import (
     encoding,
     pycompat,
     util,
 )
 
+if pycompat.TYPE_CHECKING:
+    from . import ui as uimod
+
 # BSD 'more' escapes ANSI color sequences by default. This can be disabled by
 # $MORE variable, but there's no compatible option with Linux 'more'. Given
 # OS X is widely used and most modern Unix systems would have 'less', setting
 # 'less' as the default seems reasonable.
 fallbackpager = b'less'
 
 
-def _rcfiles(path):
+def _rcfiles(path: bytes) -> List[bytes]:
     rcs = [os.path.join(path, b'hgrc')]
     rcdir = os.path.join(path, b'hgrc.d')
     try:
         rcs.extend(
             [
                 os.path.join(rcdir, f)
                 for f, kind in sorted(util.listdir(rcdir))
                 if f.endswith(b".rc")
             ]
         )
     except OSError:
         pass
     return rcs
 
 
-def systemrcpath():
+def systemrcpath() -> List[bytes]:
     path = []
     if pycompat.sysplatform == b'plan9':
         root = b'lib/mercurial'
     else:
         root = b'etc/mercurial'
     # old mod_python does not set sys.argv
     if len(getattr(sys, 'argv', [])) > 0:
         p = os.path.dirname(os.path.dirname(pycompat.sysargv[0]))
         if p != b'/':
             path.extend(_rcfiles(os.path.join(p, root)))
     path.extend(_rcfiles(b'/' + root))
     return path
 
 
-def userrcpath():
+def userrcpath() -> List[bytes]:
     if pycompat.sysplatform == b'plan9':
         return [encoding.environ[b'home'] + b'/lib/hgrc']
     elif pycompat.isdarwin:
         return [os.path.expanduser(b'~/.hgrc')]
     else:
         confighome = encoding.environ.get(b'XDG_CONFIG_HOME')
         if confighome is None or not os.path.isabs(confighome):
             confighome = os.path.expanduser(b'~/.config')
 
         return [
             os.path.expanduser(b'~/.hgrc'),
             os.path.join(confighome, b'hg', b'hgrc'),
         ]
 
 
-def termsize(ui):
+def termsize(ui: "uimod.ui") -> Tuple[int, int]:
     try:
         import termios
 
         TIOCGWINSZ = termios.TIOCGWINSZ  # unavailable on IRIX (issue3449)
     except (AttributeError, ImportError):
         return 80, 24
 
     for dev in (ui.ferr, ui.fout, ui.fin):
         try:
             try:
                 fd = dev.fileno()
             except AttributeError:
                 continue
             if not os.isatty(fd):
                 continue
             arri = fcntl.ioctl(fd, TIOCGWINSZ, b'\0' * 8)
             height, width = array.array('h', arri)[:2]
             if width > 0 and height > 0:
                 return width, height
         except ValueError:
             pass
         except IOError as e:
             if e.errno == errno.EINVAL:
                 pass
             else:
                 raise
     return 80, 24

mercurial/scmwindows.py

@@ -1,115 +1,123 b''
 import os
 
+from typing import (
+    List,
+    Tuple,
+)
+
 from . import (
     encoding,
     pycompat,
     util,
     win32,
 )
 
+if pycompat.TYPE_CHECKING:
+    from . import ui as uimod
+
 try:
     import _winreg as winreg  # pytype: disable=import-error
 
     winreg.CloseKey
 except ImportError:
     # py2 only
     import winreg  # pytype: disable=import-error
 
 # MS-DOS 'more' is the only pager available by default on Windows.
 fallbackpager = b'more'
 
 
-def systemrcpath():
+def systemrcpath() -> List[bytes]:
     '''return default os-specific hgrc search path'''
     rcpath = []
     filename = win32.executablepath()
     # Use mercurial.ini found in directory with hg.exe
     progrc = os.path.join(os.path.dirname(filename), b'mercurial.ini')
     rcpath.append(progrc)
 
-    def _processdir(progrcd):
+    def _processdir(progrcd: bytes) -> None:
         if os.path.isdir(progrcd):
             for f, kind in sorted(util.listdir(progrcd)):
                 if f.endswith(b'.rc'):
                     rcpath.append(os.path.join(progrcd, f))
 
     # Use hgrc.d found in directory with hg.exe
     _processdir(os.path.join(os.path.dirname(filename), b'hgrc.d'))
 
     # treat a PROGRAMDATA directory as equivalent to /etc/mercurial
     programdata = encoding.environ.get(b'PROGRAMDATA')
     if programdata:
         programdata = os.path.join(programdata, b'Mercurial')
         _processdir(os.path.join(programdata, b'hgrc.d'))
 
         ini = os.path.join(programdata, b'mercurial.ini')
         if os.path.isfile(ini):
             rcpath.append(ini)
 
         ini = os.path.join(programdata, b'hgrc')
         if os.path.isfile(ini):
             rcpath.append(ini)
 
     # next look for a system rcpath in the registry
     value = util.lookupreg(
         # pytype: disable=module-attr
         b'SOFTWARE\\Mercurial',
         None,
         winreg.HKEY_LOCAL_MACHINE
         # pytype: enable=module-attr
     )
     if value and isinstance(value, bytes):
         value = util.localpath(value)
         for p in value.split(pycompat.ospathsep):
             if p.lower().endswith(b'mercurial.ini'):
                 rcpath.append(p)
             else:
                 _processdir(p)
     return rcpath
 
 
-def userrcpath():
+def userrcpath() -> List[bytes]:
     '''return os-specific hgrc search path to the user dir'''
     home = _legacy_expanduser(b'~')
     path = [os.path.join(home, b'mercurial.ini'), os.path.join(home, b'.hgrc')]
     userprofile = encoding.environ.get(b'USERPROFILE')
     if userprofile and userprofile != home:
         path.append(os.path.join(userprofile, b'mercurial.ini'))
         path.append(os.path.join(userprofile, b'.hgrc'))
     return path
 
 
-def _legacy_expanduser(path):
+def _legacy_expanduser(path: bytes) -> bytes:
     """Expand ~ and ~user constructs in the pre 3.8 style"""
 
     # Python 3.8+ changed the expansion of '~' from HOME to USERPROFILE.  See
     # https://bugs.python.org/issue36264.  It also seems to capitalize the drive
     # letter, as though it was processed through os.path.realpath().
     if not path.startswith(b'~'):
         return path
 
     i, n = 1, len(path)
     while i < n and path[i] not in b'\\/':
         i += 1
 
     if b'HOME' in encoding.environ:
         userhome = encoding.environ[b'HOME']
     elif b'USERPROFILE' in encoding.environ:
         userhome = encoding.environ[b'USERPROFILE']
     elif b'HOMEPATH' not in encoding.environ:
         return path
     else:
         try:
             drive = encoding.environ[b'HOMEDRIVE']
         except KeyError:
             drive = b''
         userhome = os.path.join(drive, encoding.environ[b'HOMEPATH'])
 
     if i != 1:  # ~user
         userhome = os.path.join(os.path.dirname(userhome), path[1:i])
 
     return userhome + path[i:]
 
 
-def termsize(ui):
+def termsize(ui: "uimod.ui") -> Tuple[int, int]:
     return win32.termsize()