fix(apollo-graphql): support complex directive args (#2335)

This change fixes `transformSchema`, which previously left directives as-is
after transforming types. This meant that Input types used in directive
arguments would appear duplicated in the schema. It now recreates schema
directives and their arguments like it does with named schema types.

Fixes #2162

CHANGELOG.md

@@ -17,7 +17,7 @@
 - `apollo-env`
   - <First `apollo-env` related entry goes here>
 - `apollo-graphql`
-  - <First `apollo-graphql` related entry goes here>
+  - Complex directive arguments don't break `transformSchema` (Fixes #2162)
 - `apollo-language-server`
   - <First `apollo-language-server` related entry goes here>
 - `apollo-tools`

packages/apollo-graphql/src/schema/__tests__/transformSchema.test.ts

@@ -0,0 +1,23 @@
+import { buildSchema, printSchema } from "graphql";
+import { transformSchema } from "../transformSchema";
+
+describe("transformSchema", () => {
+  test("no-op transform leaves types untouched", () => {
+    const schema = buildSchema(`#graphql
+    type Query {
+      foo: String @test(baz: { bar: "hello" })
+    }
+
+    input DirectiveArg {
+      bar: String
+    }
+
+    # https://github.com/apollographql/apollo-tooling/issues/2162
+    directive @test(baz: DirectiveArg) on FIELD_DEFINITION
+    `);
+
+    const newSchema = transformSchema(schema, namedType => namedType);
+
+    expect(printSchema(newSchema)).toEqual(printSchema(schema));
+  });
+});

packages/apollo-graphql/src/schema/transformSchema.ts

@@ -19,7 +19,8 @@ import {
   GraphQLUnionType,
   isInputObjectType,
   GraphQLInputObjectType,
-  GraphQLInputFieldConfigMap
+  GraphQLInputFieldConfigMap,
+  GraphQLDirective
 } from "graphql";
 import { mapValues } from "../utilities/mapValues";
 
@@ -53,7 +54,8 @@ export function transformSchema(
     types: Object.values(typeMap),
     query: replaceMaybeType(schemaConfig.query),
     mutation: replaceMaybeType(schemaConfig.mutation),
-    subscription: replaceMaybeType(schemaConfig.subscription)
+    subscription: replaceMaybeType(schemaConfig.subscription),
+    directives: replaceDirectives(schemaConfig.directives)
   });
 
   function recreateNamedType(type: GraphQLNamedType): GraphQLNamedType {
@@ -145,4 +147,14 @@ export function transformSchema(
       type: replaceType(arg.type)
     }));
   }
+
+  function replaceDirectives(directives: GraphQLDirective[]) {
+    return directives.map(directive => {
+      const config = directive.toConfig();
+      return new GraphQLDirective({
+        ...config,
+        args: replaceArgs(config.args)
+      });
+    });
+  }
 }