Merge pull request #73 from brunnogrillo/fix-duplicated-fragments

Fragments validation

Author: jeggy

kgraphql/src/main/kotlin/com/apurebase/kgraphql/schema/structure/RequestInterpreter.kt

@@ -72,10 +72,16 @@ class RequestInterpreter(val schemaModel: SchemaModel) {
             OperationTypeNode.SUBSCRIPTION -> schemaModel.subscription ?: throw GraphQLError("Subscriptions are not supported on this schema")
         }
 
-        val fragmentDefinitions = test.filterIsInstance<FragmentDefinitionNode>().map { fragmentDef ->
+        val fragmentDefinitionNode = test.filterIsInstance<FragmentDefinitionNode>()
+        val fragmentDefinitions = fragmentDefinitionNode.map { fragmentDef ->
             val type = schemaModel.allTypesByName.getValue(fragmentDef.typeCondition.name.value)
+            val name = fragmentDef.name!!.value
 
-            fragmentDef.name!!.value to (type to fragmentDef.selectionSet)
+            if (fragmentDefinitionNode.count { it.name!!.value == name } > 1) {
+                throw GraphQLError("There can be only one fragment named $name.", fragmentDef )
+            }
+
+            name to (type to fragmentDef.selectionSet)
         }.toMap()
 
         val ctx = InterpreterContext(fragmentDefinitions)

kgraphql/src/test/kotlin/com/apurebase/kgraphql/specification/language/FragmentsSpecificationTest.kt

@@ -145,4 +145,28 @@ class FragmentsSpecificationTest {
         """)
         } shouldThrow GraphQLError::class withMessage "Fragment spread circular references are not allowed"
     }
+
+    @Test
+    fun `queries with duplicated fragments are denied`() {
+        invoking {
+            BaseTestSchema.execute("""
+            {
+                film {
+                    ...film_title
+                }
+            }
+            
+            fragment film_title on Film {
+                title
+            }
+            
+            fragment film_title on Film {
+                director {
+                    name
+                    age
+                }
+            }
+        """)
+        } shouldThrow GraphQLError::class withMessage "There can be only one fragment named film_title."
+    }
 }