Merge pull request #13510 from backstage/mob/factories

backend-next: incorporate options into createServiceFactory

packages/backend-plugin-api/api-report.md

@@ -109,16 +109,28 @@ export function createServiceFactory<
   TDeps extends {
     [name in string]: unknown;
   },
+  TOpts extends
+    | {
+        [name in string]: unknown;
+      }
+    | undefined = undefined,
 >(factory: {
   service: ServiceRef<TService>;
   deps: TypesToServiceRef<TDeps>;
-  factory(deps: DepsToDepFactories<TDeps>): Promise<FactoryFunc<TImpl>>;
-}): ServiceFactory<TService>;
+  factory(
+    deps: DepsToDepFactories<TDeps>,
+    options: TOpts,
+  ): Promise<FactoryFunc<TImpl>>;
+}): undefined extends TOpts
+  ? (options?: TOpts) => ServiceFactory<TService>
+  : (options: TOpts) => ServiceFactory<TService>;
 
 // @public (undocumented)
 export function createServiceRef<T>(options: {
   id: string;
-  defaultFactory?: (service: ServiceRef<T>) => Promise<ServiceFactory<T>>;
+  defaultFactory?: (
+    service: ServiceRef<T>,
+  ) => Promise<ServiceFactory<T> | (() => ServiceFactory<T>)>;
 }): ServiceRef<T>;
 
 // @public (undocumented)

packages/backend-plugin-api/src/services/system/types.test.ts

@@ -0,0 +1,89 @@
+/*
+ * Copyright 2022 The Backstage Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import { createServiceFactory, createServiceRef } from './types';
+
+describe('createServiceFactory', () => {
+  it('should create a meta factory with no options', () => {
+    const ref = createServiceRef<string>({ id: 'x' });
+    const metaFactory = createServiceFactory({
+      service: ref,
+      deps: {},
+      async factory(_deps) {
+        return async () => 'x';
+      },
+    });
+    expect(metaFactory).toEqual(expect.any(Function));
+    expect(metaFactory().service).toBe(ref);
+
+    // @ts-expect-error
+    metaFactory('string');
+    // @ts-expect-error
+    metaFactory({});
+    // @ts-expect-error
+    metaFactory({ x: 1 });
+    // @ts-expect-error
+    metaFactory(null);
+    metaFactory(undefined);
+    metaFactory();
+  });
+
+  it('should create a meta factory with optional options', () => {
+    const ref = createServiceRef<string>({ id: 'x' });
+    const metaFactory = createServiceFactory({
+      service: ref,
+      deps: {},
+      async factory(_deps, _opts?: { x: number }) {
+        return async () => 'x';
+      },
+    });
+    expect(metaFactory).toEqual(expect.any(Function));
+
+    // @ts-expect-error
+    metaFactory('string');
+    // @ts-expect-error
+    metaFactory({});
+    metaFactory({ x: 1 });
+    // @ts-expect-error
+    metaFactory(null);
+    metaFactory(undefined);
+    metaFactory();
+  });
+
+  it('should create a meta factory with required options', () => {
+    const ref = createServiceRef<string>({ id: 'x' });
+    const metaFactory = createServiceFactory({
+      service: ref,
+      deps: {},
+      async factory(_deps, _opts: { x: number }) {
+        return async () => 'x';
+      },
+    });
+    expect(metaFactory).toEqual(expect.any(Function));
+
+    // @ts-expect-error
+    metaFactory('string');
+    // @ts-expect-error
+    metaFactory({});
+    metaFactory({ x: 1 });
+    // @ts-expect-error
+    metaFactory(null);
+    // @ts-expect-error
+    metaFactory(undefined);
+    // @ts-expect-error
+    metaFactory();
+  });
+});

packages/backend-plugin-api/src/services/system/types.ts

@@ -41,7 +41,9 @@ export type InternalServiceRef<T> = ServiceRef<T> & {
    * The default factory that will be used to create service
    * instances if no other factory is provided.
    */
-  __defaultFactory?: (service: ServiceRef<T>) => Promise<ServiceFactory<T>>;
+  __defaultFactory?: (
+    service: ServiceRef<T>,
+  ) => Promise<ServiceFactory<T> | (() => ServiceFactory<T>)>;
 };
 
 /** @public */
@@ -67,7 +69,9 @@ export type ServiceFactory<TService = unknown> = {
  */
 export function createServiceRef<T>(options: {
   id: string;
-  defaultFactory?: (service: ServiceRef<T>) => Promise<ServiceFactory<T>>;
+  defaultFactory?: (
+    service: ServiceRef<T>,
+  ) => Promise<ServiceFactory<T> | (() => ServiceFactory<T>)>;
 }): ServiceRef<T> {
   const { id, defaultFactory } = options;
   return {
@@ -90,10 +94,22 @@ export function createServiceFactory<
   TService,
   TImpl extends TService,
   TDeps extends { [name in string]: unknown },
+  TOpts extends { [name in string]: unknown } | undefined = undefined,
 >(factory: {
   service: ServiceRef<TService>;
   deps: TypesToServiceRef<TDeps>;
-  factory(deps: DepsToDepFactories<TDeps>): Promise<FactoryFunc<TImpl>>;
-}): ServiceFactory<TService> {
-  return factory as ServiceFactory<TService>;
+  factory(
+    deps: DepsToDepFactories<TDeps>,
+    options: TOpts,
+  ): Promise<FactoryFunc<TImpl>>;
+}): undefined extends TOpts
+  ? (options?: TOpts) => ServiceFactory<TService>
+  : (options: TOpts) => ServiceFactory<TService> {
+  return (options?: TOpts) => ({
+    service: factory.service,
+    deps: factory.deps,
+    factory(deps: DepsToDepFactories<TDeps>) {
+      return factory.factory(deps, options!);
+    },
+  });
 }