validation-test: Test root type validation with multiple types

Extracted from graphql#3453
All credits goes to @thomasheyenbrock

Author: IvanGoncharov

src/type/__tests__/validation-test.ts

@@ -341,6 +341,13 @@ describe('Type System: A Schema must have Object root types', () => {
       input SomeInputObject {
         test: String
       }
+
+      scalar SomeScalar
+
+      enum SomeEnum {
+        ENUM_VALUE_1
+        ENUM_VALUE_2
+      }
     `);
 
     schema = extendSchema(
@@ -356,7 +363,7 @@ describe('Type System: A Schema must have Object root types', () => {
       schema,
       parse(`
         extend schema {
-          mutation: SomeInputObject
+          mutation: SomeScalar
         }
       `),
     );
@@ -365,7 +372,7 @@ describe('Type System: A Schema must have Object root types', () => {
       schema,
       parse(`
         extend schema {
-          subscription: SomeInputObject
+          subscription: SomeEnum
         }
       `),
     );
@@ -378,12 +385,12 @@ describe('Type System: A Schema must have Object root types', () => {
       },
       {
         message:
-          'Mutation root type must be Object type if provided, it cannot be SomeInputObject.',
+          'Mutation root type must be Object type if provided, it cannot be SomeScalar.',
         locations: [{ line: 3, column: 21 }],
       },
       {
         message:
-          'Subscription root type must be Object type if provided, it cannot be SomeInputObject.',
+          'Subscription root type must be Object type if provided, it cannot be SomeEnum.',
         locations: [{ line: 3, column: 25 }],
       },
     ]);