From 5f388ca50154c43d1270dcc7d4ed4648fb37a0bc Mon Sep 17 00:00:00 2001
From: Patrik Oldsberg <poldsberg@gmail.com>
Date: Fri, 2 Sep 2022 15:39:36 +0200
Subject: [PATCH] backend-plugin-api: built-in options in service factories
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Co-authored-by: Fredrik Adelöw <freben@gmail.com>
Signed-off-by: Patrik Oldsberg <poldsberg@gmail.com>
---
 .../src/services/system/types.test.ts         | 89 +++++++++++++++++++
 .../src/services/system/types.ts              | 18 +++-
 2 files changed, 104 insertions(+), 3 deletions(-)
 create mode 100644 packages/backend-plugin-api/src/services/system/types.test.ts

diff --git a/packages/backend-plugin-api/src/services/system/types.test.ts b/packages/backend-plugin-api/src/services/system/types.test.ts
new file mode 100644
index 0000000000..29512d3a58
--- /dev/null
+++ b/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();
+  });
+});
diff --git a/packages/backend-plugin-api/src/services/system/types.ts b/packages/backend-plugin-api/src/services/system/types.ts
index d622b3917f..4737c6a0e8 100644
--- a/packages/backend-plugin-api/src/services/system/types.ts
+++ b/packages/backend-plugin-api/src/services/system/types.ts
@@ -90,10 +90,22 @@ 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!);
+    },
+  });
 }