[resolvers] Add generateInternalResolversIfNeeded.__isTypeOf

.changeset/fifty-dodos-marry.md

@@ -7,5 +7,3 @@
 Add `generateInternalResolversIfNeeded` option
 
 This option can be used to generate more correct types for internal resolvers. For example, only generate `__resolveReference` if the federation object has a resolvable `@key`.
-
-In the future, this option can be extended to support other internal resolvers e.g. `__isTypeOf` is only generated for implementing types and union members.

.changeset/pink-rice-attack.md

@@ -0,0 +1,9 @@
+---
+'@graphql-codegen/visitor-plugin-common': minor
+'@graphql-codegen/typescript-resolvers': minor
+'@graphql-codegen/plugin-helpers': minor
+---
+
+Implement `generateInternalResolversIfNeeded.__isTypeOf` option
+
+When set to `true`, `__isTypeOf` resolver will only be generated for implementing types and union members.

packages/plugins/other/visitor-plugin-common/src/base-resolvers-visitor.ts

@@ -582,10 +582,9 @@ export interface RawResolversConfig extends RawConfig {
   internalResolversPrefix?: string;
   /**
    * @type object
-   * @default { __resolveReference: false }
+   * @default { __resolveReference: false, __isTypeOf: false }
    * @description If relevant internal resolvers are set to `true`, the resolver type will only be generated if the right conditions are met.
-   * Enabling this allows a more correct type generation for the resolvers.
-   * For example:
+   * Enabling this allows a more correct type generation for the resolvers:
    * - `__isTypeOf` is generated for implementing types and union members
    * - `__resolveReference` is generated for federation types that have at least one resolvable `@key` directive
    */
@@ -675,8 +674,8 @@ export class BaseResolversVisitor<
   protected _hasReferencedResolversUnionTypes = false;
   protected _hasReferencedResolversInterfaceTypes = false;
   protected _resolversUnionTypes: Record<string, string> = {};
-  protected _resolversUnionParentTypes: Record<string, string> = {};
   protected _resolversInterfaceTypes: Record<string, string> = {};
+  protected _objectTypesWithIsTypeOf: Record<string, true> = {};
   protected _rootTypeNames = new Set<string>();
   protected _globalDeclarations = new Set<string>();
   protected _federation: ApolloFederation;
@@ -722,6 +721,7 @@ export class BaseResolversVisitor<
       internalResolversPrefix: getConfigValue(rawConfig.internalResolversPrefix, '__'),
       generateInternalResolversIfNeeded: {
         __resolveReference: rawConfig.generateInternalResolversIfNeeded?.__resolveReference ?? false,
+        __isTypeOf: rawConfig.generateInternalResolversIfNeeded?.__isTypeOf ?? false,
       },
       resolversNonOptionalTypename: normalizeResolversNonOptionalTypename(
         getConfigValue(rawConfig.resolversNonOptionalTypename, false)
@@ -993,9 +993,16 @@ export class BaseResolversVisitor<
 
       if (isUnionType(schemaType)) {
         const { unionMember, excludeTypes } = this.config.resolversNonOptionalTypename;
+
+        const memberTypes = schemaType.getTypes();
+
+        for (const type of memberTypes) {
+          this._objectTypesWithIsTypeOf[type.name] = true;
+        }
+
         res[typeName] = this.getAbstractMembersType({
           typeName,
-          memberTypes: schemaType.getTypes(),
+          memberTypes,
           isTypenameNonOptional: unionMember && !excludeTypes?.includes(typeName),
         });
       }
@@ -1032,6 +1039,10 @@ export class BaseResolversVisitor<
 
         const { interfaceImplementingType, excludeTypes } = this.config.resolversNonOptionalTypename;
 
+        for (const type of implementingTypes) {
+          this._objectTypesWithIsTypeOf[type.name] = true;
+        }
+
         res[typeName] = this.getAbstractMembersType({
           typeName,
           memberTypes: implementingTypes,
@@ -1595,7 +1606,11 @@ export class BaseResolversVisitor<
       );
     });
 
-    if (!rootType) {
+    if (
+      !rootType &&
+      (!this.config.generateInternalResolversIfNeeded.__isTypeOf ||
+        (this.config.generateInternalResolversIfNeeded.__isTypeOf && this._objectTypesWithIsTypeOf[typeName]))
+    ) {
       fieldsContent.push(
         indent(
           `${

packages/plugins/other/visitor-plugin-common/src/types.ts

@@ -130,5 +130,6 @@ export interface ResolversNonOptionalTypenameConfig {
 
 export interface GenerateInternalResolversIfNeededConfig {
   __resolveReference?: boolean;
+  __isTypeOf?: boolean;
 }
 export type NormalizedGenerateInternalResolversIfNeededConfig = Required<GenerateInternalResolversIfNeededConfig>;

packages/plugins/typescript/resolvers/tests/ts-resolvers.interface.spec.ts

@@ -406,4 +406,102 @@ describe('TypeScript Resolvers Plugin - Interfaces', () => {
       };
     `);
   });
+
+  it('if generateInternalResolversIfNeeded.__isTypeOf = false (default), generates __isTypeOf for all object types', async () => {
+    const schema = buildSchema(/* GraphQL */ `
+      interface Node {
+        id: ID!
+      }
+
+      type Cat implements Node {
+        id: ID!
+        name: String!
+      }
+
+      type Dog implements Node {
+        id: ID!
+        isGoodBoy: Boolean!
+      }
+
+      type Human {
+        _id: ID!
+      }
+    `);
+
+    const result = await plugin(schema, [], {}, { outputFile: '' });
+
+    expect(result.content).toBeSimilarStringTo(`
+      export type CatResolvers<ContextType = any, ParentType extends ResolversParentTypes['Cat'] = ResolversParentTypes['Cat']> = {
+        id?: Resolver<ResolversTypes['ID'], ParentType, ContextType>;
+        name?: Resolver<ResolversTypes['String'], ParentType, ContextType>;
+        __isTypeOf?: IsTypeOfResolverFn<ParentType, ContextType>;
+      }
+    `);
+
+    expect(result.content).toBeSimilarStringTo(`
+      export type DogResolvers<ContextType = any, ParentType extends ResolversParentTypes['Dog'] = ResolversParentTypes['Dog']> = {
+        id?: Resolver<ResolversTypes['ID'], ParentType, ContextType>;
+        isGoodBoy?: Resolver<ResolversTypes['Boolean'], ParentType, ContextType>;
+        __isTypeOf?: IsTypeOfResolverFn<ParentType, ContextType>;
+      };
+    `);
+
+    expect(result.content).toBeSimilarStringTo(`
+      export type HumanResolvers<ContextType = any, ParentType extends ResolversParentTypes['Human'] = ResolversParentTypes['Human']> = {
+        _id?: Resolver<ResolversTypes['ID'], ParentType, ContextType>;
+        __isTypeOf?: IsTypeOfResolverFn<ParentType, ContextType>;
+      };
+    `);
+  });
+
+  it('if generateInternalResolversIfNeeded.__isTypeOf = true, generates __isTypeOf for only implementing object types', async () => {
+    const schema = buildSchema(/* GraphQL */ `
+      interface Node {
+        id: ID!
+      }
+
+      type Cat implements Node {
+        id: ID!
+        name: String!
+      }
+
+      type Dog implements Node {
+        id: ID!
+        isGoodBoy: Boolean!
+      }
+
+      type Human {
+        _id: ID!
+      }
+    `);
+
+    const result = await plugin(
+      schema,
+      [],
+      { generateInternalResolversIfNeeded: { __isTypeOf: true } },
+      { outputFile: '' }
+    );
+
+    expect(result.content).toBeSimilarStringTo(`
+      export type CatResolvers<ContextType = any, ParentType extends ResolversParentTypes['Cat'] = ResolversParentTypes['Cat']> = {
+        id?: Resolver<ResolversTypes['ID'], ParentType, ContextType>;
+        name?: Resolver<ResolversTypes['String'], ParentType, ContextType>;
+        __isTypeOf?: IsTypeOfResolverFn<ParentType, ContextType>;
+      }
+    `);
+
+    expect(result.content).toBeSimilarStringTo(`
+      export type DogResolvers<ContextType = any, ParentType extends ResolversParentTypes['Dog'] = ResolversParentTypes['Dog']> = {
+        id?: Resolver<ResolversTypes['ID'], ParentType, ContextType>;
+        isGoodBoy?: Resolver<ResolversTypes['Boolean'], ParentType, ContextType>;
+        __isTypeOf?: IsTypeOfResolverFn<ParentType, ContextType>;
+      };
+    `);
+
+    expect(result.content).toBeSimilarStringTo(`
+      export type HumanResolvers<ContextType = any, ParentType extends ResolversParentTypes['Human'] = ResolversParentTypes['Human']> = {
+        _id?: Resolver<ResolversTypes['ID'], ParentType, ContextType>;
+      };
+    `);
+  });
 });

packages/plugins/typescript/resolvers/tests/ts-resolvers.union.spec.ts

@@ -94,4 +94,118 @@ describe('TypeScript Resolvers Plugin - Union', () => {
     expect(content.content).not.toBeSimilarStringTo(`export type ResolversUnionTypes`);
     expect(content.content).not.toBeSimilarStringTo(`export type ResolversUnionParentTypes`);
   });
+
+  it('if generateInternalResolversIfNeeded.__isTypeOf = false (default), generates __isTypeOf for all object types', async () => {
+    const schema = buildSchema(/* GraphQL */ `
+      type MemberOne {
+        id: ID!
+      }
+
+      type MemberTwo {
+        id: ID!
+        name: String!
+      }
+
+      type MemberThree {
+        id: ID!
+        isMember: Boolean!
+      }
+
+      type Normal {
+        id: ID!
+      }
+    `);
+
+    const result = await plugin(schema, [], {}, { outputFile: '' });
+
+    expect(result.content).toBeSimilarStringTo(`
+      export type MemberOneResolvers<ContextType = any, ParentType extends ResolversParentTypes['MemberOne'] = ResolversParentTypes['MemberOne']> = {
+        id?: Resolver<ResolversTypes['ID'], ParentType, ContextType>;
+        __isTypeOf?: IsTypeOfResolverFn<ParentType, ContextType>;
+      }
+    `);
+
+    expect(result.content).toBeSimilarStringTo(`
+      export type MemberTwoResolvers<ContextType = any, ParentType extends ResolversParentTypes['MemberTwo'] = ResolversParentTypes['MemberTwo']> = {
+        id?: Resolver<ResolversTypes['ID'], ParentType, ContextType>;
+        name?: Resolver<ResolversTypes['String'], ParentType, ContextType>;
+        __isTypeOf?: IsTypeOfResolverFn<ParentType, ContextType>;
+      };
+    `);
+
+    expect(result.content).toBeSimilarStringTo(`
+      export type MemberThreeResolvers<ContextType = any, ParentType extends ResolversParentTypes['MemberThree'] = ResolversParentTypes['MemberThree']> = {
+        id?: Resolver<ResolversTypes['ID'], ParentType, ContextType>;
+        isMember?: Resolver<ResolversTypes['Boolean'], ParentType, ContextType>;
+        __isTypeOf?: IsTypeOfResolverFn<ParentType, ContextType>;
+      };
+    `);
+
+    expect(result.content).toBeSimilarStringTo(`
+      export type NormalResolvers<ContextType = any, ParentType extends ResolversParentTypes['Normal'] = ResolversParentTypes['Normal']> = {
+        id?: Resolver<ResolversTypes['ID'], ParentType, ContextType>;
+        __isTypeOf?: IsTypeOfResolverFn<ParentType, ContextType>;
+      };
+    `);
+  });
+
+  it('if generateInternalResolversIfNeeded.__isTypeOf = true, generates __isTypeOf for only union members', async () => {
+    const schema = buildSchema(/* GraphQL */ `
+      type MemberOne {
+        id: ID!
+      }
+
+      type MemberTwo {
+        id: ID!
+        name: String!
+      }
+
+      type MemberThree {
+        id: ID!
+        isMember: Boolean!
+      }
+
+      union Union = MemberOne | MemberTwo | MemberThree
+
+      type Normal {
+        id: ID!
+      }
+    `);
+
+    const result = await plugin(
+      schema,
+      [],
+      { generateInternalResolversIfNeeded: { __isTypeOf: true } },
+      { outputFile: '' }
+    );
+
+    expect(result.content).toBeSimilarStringTo(`
+      export type MemberOneResolvers<ContextType = any, ParentType extends ResolversParentTypes['MemberOne'] = ResolversParentTypes['MemberOne']> = {
+        id?: Resolver<ResolversTypes['ID'], ParentType, ContextType>;
+        __isTypeOf?: IsTypeOfResolverFn<ParentType, ContextType>;
+      }
+    `);
+
+    expect(result.content).toBeSimilarStringTo(`
+      export type MemberTwoResolvers<ContextType = any, ParentType extends ResolversParentTypes['MemberTwo'] = ResolversParentTypes['MemberTwo']> = {
+        id?: Resolver<ResolversTypes['ID'], ParentType, ContextType>;
+        name?: Resolver<ResolversTypes['String'], ParentType, ContextType>;
+        __isTypeOf?: IsTypeOfResolverFn<ParentType, ContextType>;
+      };
+    `);
+
+    expect(result.content).toBeSimilarStringTo(`
+      export type MemberThreeResolvers<ContextType = any, ParentType extends ResolversParentTypes['MemberThree'] = ResolversParentTypes['MemberThree']> = {
+        id?: Resolver<ResolversTypes['ID'], ParentType, ContextType>;
+        isMember?: Resolver<ResolversTypes['Boolean'], ParentType, ContextType>;
+        __isTypeOf?: IsTypeOfResolverFn<ParentType, ContextType>;
+      };
+    `);
+
+    expect(result.content).toBeSimilarStringTo(`
+      export type NormalResolvers<ContextType = any, ParentType extends ResolversParentTypes['Normal'] = ResolversParentTypes['Normal']> = {
+        id?: Resolver<ResolversTypes['ID'], ParentType, ContextType>;
+      };
+    `);
+  });
 });