Adds support for custom enum value resolvers (#508)

* Add support for custom enum values * Adds support for custom values in Enums on a schema Signed-off-by: Sarah Weir <sweir27@gmail.com> * Adds some extra tests around merged schemas Signed-off-by: Sarah Weir <sweir27@gmail.com> * Tighten the types on a custom Enum definition * Adds an 'as any' to the type when it is known as an enum
ardatan · Nov 28, 2017 · 907b8a1 · 907b8a1
1 parent 499ab8e
commit 907b8a1
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diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -2,7 +2,8 @@
 
 ### VNEXT
 
-* ...
+* Added basic support for custom Enums [Issue #363](https://github.com/apollographql/graphql-tools/issues/363) [PR #507](https://github.com/apollographql/graphql-tools/pull/507)
+
 
 ### v2.9.0
 

diff --git a/src/Interfaces.ts b/src/Interfaces.ts
@@ -31,8 +31,9 @@ export type ITypeDefinitions = ITypedef | ITypedef[];
 export type IResolverObject = {
   [key: string]: GraphQLFieldResolver<any, any> | IResolverOptions;
 };
+export type IEnumResolver = { [key: string]: string };
 export interface IResolvers {
-  [key: string]: (() => any) | IResolverObject | GraphQLScalarType;
+  [key: string]: (() => any) | IResolverObject | GraphQLScalarType | IEnumResolver;
 }
 export interface ILogger {
   log: (message: string | Error) => void;

diff --git a/src/schemaGenerator.ts b/src/schemaGenerator.ts
@@ -7,6 +7,7 @@
 // a bunch of utility functions into a separate utitlities folder, one file per function.
 
 import {
+  GraphQLEnumType,
   DocumentNode,
   parse,
   print,
@@ -372,6 +373,19 @@ function addResolveFunctionsToSchema(
         return;
       }
 
+      if (type instanceof GraphQLEnumType) {
+        // TODO: Remove once https://github.com/DefinitelyTyped/DefinitelyTyped/pull/21786
+        // is inside NPM
+        if (!(type as any).isValidValue(fieldName)) {
+          throw new SchemaError(
+              `${typeName}.${fieldName} was defined in resolvers, but enum is not in schema`,
+          );
+        }
+
+        type.getValue(fieldName)['value'] = resolveFunctions[typeName][fieldName];
+        return;
+      }
+
       const fields = getFieldsForType(type);
       if (!fields) {
         if (allowResolversNotInSchema) {

diff --git a/src/test/testMergeSchemas.ts b/src/test/testMergeSchemas.ts
@@ -21,6 +21,7 @@ import {
   subscriptionPubSubTrigger,
 } from './testingSchemas';
 import { forAwaitEach } from 'iterall';
+import { makeExecutableSchema } from '../schemaGenerator';
 
 const testCombinations = [
   { name: 'local', booking: localBookingSchema, property: localPropertySchema },
@@ -53,6 +54,22 @@ const scalarTest = `
   }
 `;
 
+
+const enumTest = `
+# A type that uses an Enum.
+enum Color {
+  RED
+}
+
+schema {
+  query: Query
+}
+
+type Query {
+  color: Color
+}
+`;
+
 const linkSchema = `
   # A new type linking the Property type.
   type LinkType {
@@ -107,6 +124,7 @@ testCombinations.forEach(async combination => {
           propertySchema,
           bookingSchema,
           scalarTest,
+          enumTest,
           linkSchema,
           localSubscriptionSchema,
         ],
@@ -118,6 +136,9 @@ testCombinations.forEach(async combination => {
             parseValue: value => value,
             parseLiteral: () => null,
           }),
+          Color: {
+            RED: '#EA3232'
+          },
           Property: {
             bookings: {
               fragment: 'fragment PropertyFragment on Property { id }',
@@ -167,6 +188,9 @@ testCombinations.forEach(async combination => {
             },
           },
           Query: {
+            color() {
+              return '#EA3232';
+            },
             delegateInterfaceTest(parent, args, context, info) {
               return mergeInfo.delegate(
                 'query',
@@ -322,6 +346,46 @@ testCombinations.forEach(async combination => {
         expect(mergedResult).to.deep.equal(propertyResult);
       });
 
+      it('works with custom enums', async () => {
+        const enumSchema = makeExecutableSchema({
+          typeDefs: enumTest,
+          resolvers: {
+            Color: {
+              RED: '#EA3232'
+            },
+            Query: {
+              color() {
+                return '#EA3232';
+              },
+            },
+          }
+        });
+        const enumResult = await graphql(
+          enumSchema,
+          `
+            query {
+              color
+            }
+          `,
+        );
+
+        const mergedResult = await graphql(
+          mergedSchema,
+          `
+            query {
+              color
+            }
+          `,
+        );
+
+        expect(enumResult).to.deep.equal({
+          data: {
+            color: 'RED',
+          },
+        });
+        expect(mergedResult).to.deep.equal(enumResult);
+      });
+
       it('queries', async () => {
         const propertyFragment = `
 propertyById(id: "p1") {
@@ -1392,6 +1456,10 @@ bookingById(id: $b1) {
           'A type that uses TestScalar.',
         );
 
+        expect(mergedSchema.getType('Color').description).to.equal(
+          'A type that uses an Enum.',
+        );
+
         expect(mergedSchema.getType('LinkType').description).to.equal(
           'A new type linking the Property type.',
         );