can now get whether an item changed, but not when an item changes from non-DVC to DVC

dvc/dependency/repo.py

@@ -1,6 +1,7 @@
 import copy
 import os
 from contextlib import contextmanager
+import filecmp
 
 from funcy import merge
 
@@ -52,7 +53,7 @@ class DependencyREPO(DependencyLOCAL):
             PathInfo(os.path.join(repo.root_dir, self.def_path))
         )
 
-    def status(self):
+    def _has_changed(self):
         with self._make_repo() as repo, self._make_repo(
             rev_lock=None
         ) as updated_repo:
@@ -60,16 +61,53 @@ class DependencyREPO(DependencyLOCAL):
                 current = repo.find_out_by_relpath(self.def_path).info
                 updated = updated_repo.find_out_by_relpath(self.def_path).info
 
-                has_changed = current != updated
+                return current != updated
             except OutputNotFoundError:
                 # Need to load the state before calculating checksums
                 repo.state.load()
                 updated_repo.state.load()
 
-                has_changed = self._get_checksum_in_repo(
+                return self._get_checksum_in_repo(
                     repo
                 ) != self._get_checksum_in_repo(updated_repo)
 
+    def _has_changed_non_dvc(self):
+        url = self.def_repo[self.PARAM_URL]
+        rev = self.def_repo.get(self.PARAM_REV)
+        rev_lock = self.def_repo.get(self.PARAM_REV_LOCK, rev)
+
+        current_repo = cached_clone(url, rev=rev_lock or rev)
+        updated_repo = cached_clone(url, rev=rev)
+
+        current_path = os.path.join(current_repo, self.def_path)
+        updated_path = os.path.join(updated_repo, self.def_path)
+
+        if not os.path.exists(current_path):
+            raise FileNotFoundError(current_path)
+
+        if not os.path.exists(updated_path):
+            raise FileNotFoundError(updated_path)
+
+        is_dir = os.path.isdir(current_path)
+
+        assert is_dir == os.path.isdir(updated_path)
+
+        if is_dir:
+            comparison = filecmp.dircmp(current_path, updated_path)
+            return not (
+                comparison.left_only
+                or comparison.right_only
+                or comparison.diff_files
+            )
+
+        return not filecmp.cmp(current_path, updated_path, shallow=False)
+
+    def status(self):
+        try:
+            has_changed = self._has_changed()
+        except NotDvcRepoError:
+            has_changed = self._has_changed_non_dvc()
+
         if has_changed:
             return {str(self): "update available"}
 

tests/func/test_status.py

@@ -1,9 +1,12 @@
 import os
+import shutil
 
 from mock import patch
 
 from dvc.main import main
+from dvc.compat import fspath
 from tests.basic_env import TestDvc
+from dvc.external_repo import clean_repos
 
 
 class TestStatus(TestDvc):
@@ -23,3 +26,35 @@ class TestStatus(TestDvc):
     def test_implied_cloud(self, mock_status):
         main(["status", "--remote", "something"])
         mock_status.assert_called()
+
+
+def test_status_non_dvc_repo_import(tmp_dir, dvc, erepo_dir):
+    with erepo_dir.branch("branch", new=True), erepo_dir.chdir():
+        erepo_dir.scm.repo.index.remove([".dvc"], r=True)
+        shutil.rmtree(".dvc")
+        erepo_dir.scm_gen("file", "first version")
+        erepo_dir.scm.add(["file"])
+        erepo_dir.scm.commit("first version")
+
+    dvc.imp(fspath(erepo_dir), "file", "file", rev="branch")
+
+    status = dvc.status(["file.dvc"])
+
+    assert status == {}
+
+    # Caching in external repos doesn't see upstream updates within single
+    # cli call, so we need to clean the caches to see the changes.
+    clean_repos()
+
+    with erepo_dir.branch("branch", new=False), erepo_dir.chdir():
+        erepo_dir.scm_gen("file", "second_version", commit="update file")
+        erepo_dir.scm.add(["file"])
+        erepo_dir.scm.commit("first version")
+
+    status, = dvc.status(["file.dvc"])["file.dvc"]
+
+    assert status == {
+        "changed deps": {
+            "file ({})".format(fspath(erepo_dir)): "update available"
+        }
+    }