Allow __typename in union type validation

aPureBase · Jun 24, 2019 · 9cf5d3c · 9cf5d3c
1 parent 067359f
commit 9cf5d3c
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Showing 2 changed files with 18 additions and 2 deletions.
diff --git a/src/main/kotlin/com/apurebase/kgraphql/schema/structure2/Validation.kt b/src/main/kotlin/com/apurebase/kgraphql/schema/structure2/Validation.kt
@@ -49,11 +49,11 @@ fun Field.validateArguments(selectionArgs: Arguments?, parentTypeName : String?)
 
 
 /**
- * validate that only typed fragments are present
+ * validate that only typed fragments or __typename are present
  */
 fun validateUnionRequest(field: Field.Union<*>, selectionNode: SelectionNode) {
     val illegalChildren = selectionNode.children?.filterNot {
-        it is Fragment.Inline || it is Fragment.External
+        it is Fragment.Inline || it is Fragment.External || it.key == "__typename"
     }
 
     if (illegalChildren?.any() ?: false) {

diff --git a/src/test/kotlin/com/apurebase/kgraphql/specification/typesystem/UnionsSpecificationTest.kt b/src/test/kotlin/com/apurebase/kgraphql/specification/typesystem/UnionsSpecificationTest.kt
@@ -53,6 +53,22 @@ class UnionsSpecificationTest : BaseSchemaTest() {
         }
     }
 
+    @Test
+    fun `A Union type should allow requesting __typename`() {
+        val result = execute("""{
+            actors {
+                name
+                favourite {
+                    ... on Actor { name }
+                    ... on Director { name, age }
+                    ... on Scenario { content(uppercase: false) }
+                    __typename
+                }
+            }
+        }""".trimIndent())
+        println(result)
+    }
+
     @Test
     fun `The member types of a Union type must all be Object base types`(){
         expect<SchemaException>("The member types of a Union type must all be Object base types"){