buildClientSchema: include standard type only if it is used (#1809)

Details: 183ff32#r32971387

src/utilities/__tests__/buildClientSchema-test.js

@@ -40,9 +40,6 @@ function cycleIntrospection(sdlString) {
   const clientSchema = buildClientSchema(initialIntrospection);
   const secondIntrospection = introspectionFromSchema(clientSchema);
 
-  hackToRemoveStandardTypes(secondIntrospection);
-  hackToRemoveStandardTypes(initialIntrospection);
-
   /**
    * If the client then runs the introspection query against the client-side
    * schema, it should get a result identical to what was returned by the server
@@ -51,14 +48,6 @@ function cycleIntrospection(sdlString) {
   return printSchema(clientSchema);
 }
 
-// Temporary hack to remove always presented standard types should be removed in 15.0
-function hackToRemoveStandardTypes(introspection) {
-  (introspection.__schema: any).types = introspection.__schema.types.filter(
-    ({ name }) =>
-      ['ID', 'Float', 'Int', 'Boolean', 'String'].indexOf(name) === -1,
-  );
-}
-
 describe('Type System: build schema from introspection', () => {
   it('builds a simple schema', () => {
     const sdl = dedent`
@@ -138,6 +127,20 @@ describe('Type System: build schema from introspection', () => {
     expect(clientSchema.getType('CustomScalar')).not.to.equal(customScalar);
   });
 
+  it('include standard type only if it is used', () => {
+    const schema = buildSchema(`
+      type Query {
+        foo: String
+      }
+    `);
+    const introspection = introspectionFromSchema(schema);
+    const clientSchema = buildClientSchema(introspection);
+
+    expect(clientSchema.getType('Int')).to.equal(undefined);
+    expect(clientSchema.getType('Float')).to.equal(undefined);
+    expect(clientSchema.getType('ID')).to.equal(undefined);
+  });
+
   it('builds a schema with a recursive type reference', () => {
     const sdl = dedent`
       schema {
@@ -329,10 +332,8 @@ describe('Type System: build schema from introspection', () => {
 
     const introspection = introspectionFromSchema(schema);
     const clientSchema = buildClientSchema(introspection);
-    const secondIntrospection = introspectionFromSchema(clientSchema);
 
-    hackToRemoveStandardTypes(secondIntrospection);
-    hackToRemoveStandardTypes(introspection);
+    const secondIntrospection = introspectionFromSchema(clientSchema);
     expect(secondIntrospection).to.deep.equal(introspection);
 
     const clientFoodEnum = clientSchema.getType('Food');

src/utilities/buildClientSchema.js

@@ -90,7 +90,9 @@ export function buildClientSchema(
   );
 
   for (const stdType of [...specifiedScalarTypes, ...introspectionTypes]) {
-    typeMap[stdType.name] = stdType;
+    if (typeMap[stdType.name]) {
+      typeMap[stdType.name] = stdType;
+    }
   }
 
   // Get the root Query, Mutation, and Subscription types.