From c91cad9746cee8d3367738bb4c3038ff17c21b3a Mon Sep 17 00:00:00 2001
From: Yaacov Rydzinski <yaacovCR@gmail.com>
Date: Tue, 9 Jun 2020 15:24:52 -0400
Subject: [PATCH] addResolversToSchema should merge scalar/enum resolvers

instead of overwriting

closes #1587
---
 packages/schema/src/addResolversToSchema.ts   | 57 +++++++++++++++++++
 packages/schema/tests/schemaGenerator.test.ts | 29 ++++++++++
 2 files changed, 86 insertions(+)

diff --git a/packages/schema/src/addResolversToSchema.ts b/packages/schema/src/addResolversToSchema.ts
index 42657629caf..a49f1202c4e 100644
--- a/packages/schema/src/addResolversToSchema.ts
+++ b/packages/schema/src/addResolversToSchema.ts
@@ -28,6 +28,7 @@ import {
   healSchema,
   parseInputValue,
   forEachField,
+  mergeDeep,
 } from '@graphql-tools/utils';
 
 import { checkForResolveTypeResolver } from './checkForResolveTypeResolver';
@@ -163,6 +164,20 @@ function addResolversToExistingSchema(
         Object.keys(resolverValue).forEach(fieldName => {
           if (fieldName.startsWith('__')) {
             type[fieldName.substring(2)] = resolverValue[fieldName];
+          } else if (fieldName === 'astNode' && type.astNode != null) {
+            type.astNode = {
+              ...type.astNode,
+              description: (resolverValue as GraphQLScalarType)?.astNode?.description ?? type.astNode.description,
+              directives: (type.astNode.directives ?? []).concat(
+                (resolverValue as GraphQLScalarType)?.astNode?.directives ?? []
+              ),
+            };
+          } else if (fieldName === 'extensionASTNodes' && type.extensionASTNodes != null) {
+            type.extensionASTNodes = ([] ?? type.extensionASTNodes).concat(
+              (resolverValue as GraphQLScalarType)?.extensionASTNodes ?? []
+            );
+          } else if (fieldName === 'extensions' && type.extensions != null) {
+            type.extensions = mergeDeep({}, type.extensions, (resolverValue as GraphQLScalarType).extensions);
           } else {
             type[fieldName] = resolverValue[fieldName];
           }
@@ -174,6 +189,20 @@ function addResolversToExistingSchema(
         Object.keys(resolverValue).forEach(fieldName => {
           if (fieldName.startsWith('__')) {
             config[fieldName.substring(2)] = resolverValue[fieldName];
+          } else if (fieldName === 'astNode' && config.astNode != null) {
+            config.astNode = {
+              ...config.astNode,
+              description: (resolverValue as GraphQLScalarType)?.astNode?.description ?? config.astNode.description,
+              directives: (config.astNode.directives ?? []).concat(
+                (resolverValue as GraphQLEnumType)?.astNode?.directives ?? []
+              ),
+            };
+          } else if (fieldName === 'extensionASTNodes' && config.extensionASTNodes != null) {
+            config.extensionASTNodes = config.extensionASTNodes.concat(
+              (resolverValue as GraphQLEnumType)?.extensionASTNodes ?? []
+            );
+          } else if (fieldName === 'extensions' && config.extensions != null) {
+            type.extensions = mergeDeep({}, config.extensions, (resolverValue as GraphQLEnumType).extensions);
           } else if (enumValueConfigMap[fieldName]) {
             enumValueConfigMap[fieldName].value = resolverValue[fieldName];
           }
@@ -242,6 +271,20 @@ function createNewSchemaWithResolvers(
         Object.keys(resolverValue).forEach(fieldName => {
           if (fieldName.startsWith('__')) {
             config[fieldName.substring(2)] = resolverValue[fieldName];
+          } else if (fieldName === 'astNode' && config.astNode != null) {
+            config.astNode = {
+              ...config.astNode,
+              description: (resolverValue as GraphQLScalarType)?.astNode?.description ?? config.astNode.description,
+              directives: (config.astNode.directives ?? []).concat(
+                (resolverValue as GraphQLScalarType)?.astNode?.directives ?? []
+              ),
+            };
+          } else if (fieldName === 'extensionASTNodes' && config.extensionASTNodes != null) {
+            config.extensionASTNodes = config.extensionASTNodes.concat(
+              (resolverValue as GraphQLScalarType)?.extensionASTNodes ?? []
+            );
+          } else if (fieldName === 'extensions' && config.extensions != null) {
+            config.extensions = mergeDeep({}, type.extensions, (resolverValue as GraphQLScalarType).extensions);
           } else {
             config[fieldName] = resolverValue[fieldName];
           }
@@ -260,6 +303,20 @@ function createNewSchemaWithResolvers(
         Object.keys(resolverValue).forEach(fieldName => {
           if (fieldName.startsWith('__')) {
             config[fieldName.substring(2)] = resolverValue[fieldName];
+          } else if (fieldName === 'astNode' && config.astNode != null) {
+            config.astNode = {
+              ...config.astNode,
+              description: (resolverValue as GraphQLScalarType)?.astNode?.description ?? config.astNode.description,
+              directives: (config.astNode.directives ?? []).concat(
+                (resolverValue as GraphQLEnumType)?.astNode?.directives ?? []
+              ),
+            };
+          } else if (fieldName === 'extensionASTNodes' && config.extensionASTNodes != null) {
+            config.extensionASTNodes = config.extensionASTNodes.concat(
+              (resolverValue as GraphQLEnumType)?.extensionASTNodes ?? []
+            );
+          } else if (fieldName === 'extensions' && config.extensions != null) {
+            config.extensions = mergeDeep({}, type.extensions, (resolverValue as GraphQLEnumType).extensions);
           } else if (enumValueConfigMap[fieldName]) {
             enumValueConfigMap[fieldName].value = resolverValue[fieldName];
           }
diff --git a/packages/schema/tests/schemaGenerator.test.ts b/packages/schema/tests/schemaGenerator.test.ts
index b8c5dc609ef..c59f32e8126 100644
--- a/packages/schema/tests/schemaGenerator.test.ts
+++ b/packages/schema/tests/schemaGenerator.test.ts
@@ -838,6 +838,35 @@ describe('generating schema from shorthand', () => {
       });
     });
 
+    test('retains original scalar directives when passing in scalars in resolve functions', () => {
+      const schema = makeExecutableSchema({
+        typeDefs: `
+          directive @test on SCALAR
+
+          scalar Test @test
+
+          type Query {
+            test: Test
+          }
+        `,
+        resolvers: {
+          Test: new GraphQLScalarType({
+            name: 'Test',
+            description: 'Test resolver',
+            serialize: (value) => value,
+            parseValue: (value) => value,
+          }),
+          Query: {
+            test: () => 42,
+          },
+        },
+      });
+
+      const testType = schema.getType('Test');
+      expect(testType).toBeInstanceOf(GraphQLScalarType);
+      expect(testType.astNode.directives.length).toBe(1);
+    });
+
     test('retains scalars after walking/recreating the schema', () => {
       const shorthand = `
         scalar Test