scm: add config option to stage files automatically

dvc/config.py

@@ -137,6 +137,7 @@ class RelPath(str):
         Optional("analytics", default=True): Bool,
         Optional("hardlink_lock", default=False): Bool,
         Optional("no_scm", default=False): Bool,
+        Optional("autostage", default=False): Bool,
         Optional("experiments", default=False): Bool,
         Optional("check_update", default=True): Bool,
     },

dvc/repo/scm_context.py

@@ -3,7 +3,11 @@ def run(repo, *args, **kw):
         try:
             result = method(repo, *args, **kw)
             repo.scm.reset_ignores()
-            repo.scm.remind_to_track()
+            autostage = repo.config.get("core", {}).get("autostage", False)
+            if autostage:
+                repo.scm.track_changed_files()
+            else:
+                repo.scm.remind_to_track()
             repo.scm.reset_tracked_files()
             return result
         except Exception:

dvc/scm/base.py

@@ -154,6 +154,11 @@ def remind_to_track(self):
         Method to remind user to track newly created files handled by scm
         """
 
+    def track_changed_files(self):
+        """
+        Method to stage files that have changed
+        """
+
     def track_file(self, path):
         """
         Method to add file to mechanism that will remind user

dvc/scm/git.py

@@ -381,6 +381,12 @@ def remind_to_track(self):
             "\tgit add {files}".format(files=files)
         )
 
+    def track_changed_files(self):
+        if not self.files_to_track:
+            return
+
+        self.add(self.files_to_track)
+
     def track_file(self, path):
         self.files_to_track.add(path)
 

tests/unit/scm/test_scm.py

@@ -17,6 +17,7 @@ def test_should_successfully_perform_method(self):
         method = mock.Mock()
         wrapped = scm_context(method)
 
+        self.repo_mock.configure_mock(config={})
         wrapped(self.repo_mock)
 
         self.assertEqual(1, method.call_count)
@@ -25,6 +26,20 @@ def test_should_successfully_perform_method(self):
 
         self.assertEqual(0, self.scm_mock.cleanup_ignores.call_count)
 
+    def test_should_check_autostage(self):
+        method = mock.Mock()
+        wrapped = scm_context(method)
+
+        config_autostage_attrs = {"config": {"core": {"autostage": True}}}
+        self.repo_mock.configure_mock(**config_autostage_attrs)
+        wrapped(self.repo_mock)
+
+        self.assertEqual(1, method.call_count)
+        self.assertEqual(1, self.scm_mock.reset_ignores.call_count)
+        self.assertEqual(1, self.scm_mock.track_changed_files.call_count)
+
+        self.assertEqual(0, self.scm_mock.cleanup_ignores.call_count)
+
     def test_should_throw_and_cleanup(self):
         method = mock.Mock(side_effect=Exception("some problem"))
         wrapped = scm_context(method)