Add static typing for vcs module

src/diffuse/vcs/folder_set.py

@@ -19,6 +19,8 @@
 
 import os
 
+from typing import List
+
 
 class FolderSet:
     '''Utility class to help support Git and Monotone.
@@ -27,18 +29,18 @@ class FolderSet:
     "mtn automate inventory."
     '''
 
-    def __init__(self, names):
-        self.folders = f = []
+    def __init__(self, names: List[str]) -> None:
+        self.folders: List[str] = []
         for name in names:
             name = os.path.abspath(name)
             # ensure all names end with os.sep
             if not name.endswith(os.sep):
                 name += os.sep
-            f.append(name)
+            self.folders.append(name)
 
     # returns True if the given abspath is a file that should be included in
     # the interesting file subset
-    def contains(self, abspath):
+    def contains(self, abspath: str) -> bool:
         if not abspath.endswith(os.sep):
             abspath += os.sep
         for f in self.folders:

src/diffuse/vcs/hg.py

@@ -30,7 +30,7 @@ from diffuse.vcs.vcs_interface import VcsInterface
 # Mercurial support
 class Hg(VcsInterface):
     def __init__(self, root: str):
-        VcsInterface.__init__(self, root)
+        super().__init__(root)
         self.working_rev: Optional[str] = None
 
     def _getPreviousRevision(self, prefs, rev):

src/diffuse/vcs/svn.py

@@ -33,7 +33,7 @@ from diffuse.vcs.vcs_interface import VcsInterface
 # SVK support subclasses from this
 class Svn(VcsInterface):
     def __init__(self, root: str):
-        VcsInterface.__init__(self, root)
+        super().__init__(root)
         self.url: Optional[str] = None
 
     @staticmethod
@@ -61,7 +61,7 @@ class Svn(VcsInterface):
         m = int(rev)
         return str(max(m > 1, 0))
 
-    def _getURL(self, prefs):
+    def _getURL(self, prefs: Preferences) -> Optional[str]:
         if self.url is None:
             vcs, prefix = self._getVcs(), self._getURLPrefix()
             n = len(prefix)

src/diffuse/vcs/vcs_interface.py

@@ -17,12 +17,13 @@
 # with this program; if not, write to the Free Software Foundation, Inc.,
 # 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 
+from abc import ABCMeta, abstractmethod
 from typing import List, Optional, Tuple
 
 from diffuse.preferences import Preferences
 
 
-class VcsInterface:
+class VcsInterface(metaclass=ABCMeta):
     """Interface for the VCSs."""
 
     PathRevisionPair = Tuple[Optional[str], Optional[str]]
@@ -32,15 +33,19 @@ class VcsInterface:
         """The object will initialized with the repository's root folder."""
         self.root = root
 
+    @abstractmethod
     def getFileTemplate(self, prefs: Preferences, name: str) -> PathRevisionList:
         """Indicates which revisions to display for a file when none were explicitly
            requested."""
 
+    @abstractmethod
     def getCommitTemplate(self, prefs, rev, names):
         """Indicates which file revisions to display for a commit."""
 
+    @abstractmethod
     def getFolderTemplate(self, prefs, names):
         """Indicates which file revisions to display for a set of folders."""
 
+    @abstractmethod
     def getRevision(self, prefs: Preferences, name: str, rev: str) -> bytes:
         """Returns the contents of the specified file revision"""

src/diffuse/vcs/vcs_registry.py

@@ -186,7 +186,8 @@ def _get_svk_repo(path: str, prefs: Preferences) -> Optional[VcsInterface]:
             # find working copies by parsing the config file
             with open(svkconfig, 'r', encoding='utf-8') as f:
                 ss: List[str] = utils.readlines(f)
-            projs, sep = [], os.sep
+            projs: List[str] = []
+            sep = os.sep
             # find the separator character
             for s in ss:
                 if s.startswith('  sep: ') and len(s) > 7: