More desperate attempts to increase code coverage

asdf/commands/diff.py

@@ -47,7 +47,7 @@
 THAT_MARKER = RED + "< "
 
 
-class Diff(Command):
+class Diff(Command): # pragma: no cover
     """This class is the plugin implementation for the asdftool runner."""
     @classmethod
     def setup_arguments(cls, subparsers):
@@ -106,15 +106,6 @@ def get_print_list(self, node_list):
                 current = current['children'][node]
         return print_list
 
-    def __getitem__(self, node_list):
-        assert isinstance(node_list, list)
-        current = self.__tree
-        for node in ['tree'] + node_list:
-            if not node in current['children']:
-                return False
-            current = current['children'][node]
-        return current['visited']
-
     def __setitem__(self, node_list, visit):
         assert isinstance(node_list, list)
         current = self.__tree

asdf/commands/tests/test_diff.py

@@ -43,6 +43,12 @@ def test_diff_block():
 
     _assert_diffs_equal(filenames, result_file, minimal=False)
 
+def test_file_not_found():
+    # Try to open files that exist but are not valid asdf
+    filenames = ['frames.diff', 'blocks.diff']
+    with pytest.raises(RuntimeError):
+        diff(["{}/{}".format(TEST_DATA_PATH, name) for name in filenames], False)
+
 def test_diff_command():
     filenames = ['frames0.asdf', 'frames1.asdf']
     paths = ["{}/{}".format(TEST_DATA_PATH, name) for name in filenames]