test: add test for bad dir cache files

Signed-off-by: Ruslan Kuprieiev <[email protected]>

tests/test_cache.py

@@ -2,6 +2,7 @@ import os
 
 from dvc.cache import Cache
 from dvc.system import System
+from dvc.output import Output
 
 from tests.basic_env import TestDvc
 
@@ -42,3 +43,18 @@ class TestCache(TestDvc):
 
         self.assertEqual(len(cache), 2)
         self.assertEqual(cache, expected)
+
+
+class TestCacheLoadBadDirCache(TestDvc):
+    def _do_test(self, ret):
+        self.assertTrue(isinstance(ret, list))
+        self.assertEqual(len(ret), 0)
+
+    def test(self):
+        fname = 'not-json'
+        self.create(fname, '<clearly>not,json')
+        self._do_test(Output.load_dir_cache(fname))
+
+        fname = 'not-list'
+        self.create(fname, '{"a": "b"}')
+        self._do_test(Output.load_dir_cache(fname))