Fix validators to be aware of type-condition-less inline frags.

Author: jhgg

graphql/core/validation/rules.py

@@ -83,7 +83,7 @@ class FragmentsOnCompositeTypes(ValidationRule):
     def enter_InlineFragment(self, node, *args):
         type = self.context.get_type()
 
-        if type and not is_composite_type(type):
+        if node.type_condition and type and not is_composite_type(type):
             return GraphQLError(
                 self.inline_fragment_on_non_composite_error_message(print_ast(node.type_condition)),
                 [node.type_condition]
@@ -910,8 +910,13 @@ def collect_field_asts_and_defs(self, parent_type, selection_set, visited_fragme
                 ast_and_defs[response_name].append((selection, field_def))
 
             elif isinstance(selection, ast.InlineFragment):
+                type_condition = selection.type_condition
+                inline_fragment_type = \
+                    type_from_ast(self.context.get_schema(), type_condition) \
+                    if type_condition else parent_type
+
                 self.collect_field_asts_and_defs(
-                    type_from_ast(self.context.get_schema(), selection.type_condition),
+                    inline_fragment_type,
                     selection.selection_set,
                     visited_fragment_names,
                     ast_and_defs

tests/core_validation/test_fragments_on_composite_types.py

@@ -43,6 +43,16 @@ def test_object_is_valid_inline_fragment_type():
     ''')
 
 
+def test_inline_fragment_without_type_is_valid():
+    expect_passes_rule(FragmentsOnCompositeTypes, '''
+    fragment validFragment on Pet {
+      ... {
+        name
+      }
+    }
+    ''')
+
+
 def test_union_is_valid_fragment_type():
     expect_passes_rule(FragmentsOnCompositeTypes, '''
       fragment validFragment on CatOrDog {

tests/core_validation/test_overlapping_fields_can_be_merged.py

@@ -344,6 +344,17 @@ def test_same_wrapped_scalar_return_types():
     ''')
 
 
+def test_allows_inline_typeless_fragments():
+    expect_passes_rule_with_schema(schema, OverlappingFieldsCanBeMerged, '''
+    {
+        a
+        ... {
+            a
+        }
+    }
+    ''')
+
+
 def test_compares_deep_types_including_list():
     expect_fails_rule_with_schema(schema, OverlappingFieldsCanBeMerged, '''
     {