TypeScriptでWebアプリを使っていて、DI (Dependency injection)が
必要だったので、microsoft/tsyringeを使った見たのだが、
どうも依存注入の順番がすごく大事らしい。
依存注入されるcontrollers/freee.tsよりも先にservices/freeeHrService.tsを
ContainerにRegisrしないと実行時にError: Cannot inject the dependency "freeeService" at position #0 of "FreeeController" constructor. Reason:という大エラーになる。
依存注入するクラスとされるクラスの実装
// controllers/freee.ts
import ejs from 'ejs';
import { Request, Response } from 'express';
import path from 'path';
import { inject, injectable, singleton } from 'tsyringe';
import { FreeeService } from '../services/freeeHrService';
@singleton()
export class FreeeController {
constructor(@inject(FreeeService) private readonly freeeService: FreeeService) { }
public async get(req: Request, res: Response): Promise<void> {
// サービスを利用するロジックを記述します。
const getValue = this.freeeService.get();
const indexPath = path.join(__dirname, './../views/freee/index.ejs')
const renderedBody = await ejs.renderFile(indexPath, { contents: getValue });
res.render('layout', {
title: 'Top',
body: renderedBody
});
}
}
// services/freeeHrService.ts
import { inject, injectable, singleton } from "tsyringe";
import { FreeeHrHttpApiClient, FreeeHttpOAuthClient } from "../httpClients/freeeHttpClient";
@singleton()
export class FreeeService {
constructor(
@inject(FreeeHttpOAuthClient) private oauthClient: FreeeHttpOAuthClient,
@inject(FreeeHrHttpApiClient) private apiClient: FreeeHrHttpApiClient
) { }
public get(): string {
// Check if both oauthClient and apiClient instances are present
if (this.oauthClient && this.apiClient) {
return "Both instances are present";
}
return "One or both instances are missing";
}
}
エラーが発生するDI設定
// routes/index.ts
import 'reflect-metadata';
import { container } from 'tsyringe';
import express from 'express';
import { asyncHandler } from '../middlewares/asyncHandler';
import { FreeeHttpOAuthClient } from '../httpClients/freeeHttpClient';
import { TopController } from '../controllers/top';
import { FreeeController } from '../controllers/freee';
// controller
const router = express.Router();
const topController = container.resolve(TopController);
const freeeController = container.resolve(FreeeController);
router.get('/', asyncHandler((req, res) => topController.get(req, res)));
router.get('/freee', asyncHandler((req, res) => freeeController.get(req, res)));
// services
container.register<FreeeHttpOAuthClient>(FreeeHttpOAuthClient, { useValue: new FreeeHttpOAuthClient("YourClientId", "YourClientSecret") });
export default router;
エラーメッセージ
node_modules/tsyringe/dist/cjs/dependency-container.js:297
})();
^
Error: Cannot inject the dependency "freeeService" at position #0 of "FreeeController" constructor. Reason:
Cannot inject the dependency "oauthClient" at position #0 of "FreeeService" constructor. Reason:
Cannot inject the dependency "clientId" at position #0 of "FreeeHttpOAuthClient" constructor. Reason:
TypeInfo not known for "String"
原因は、servicesがcontroller後に書かれているからダメらしい msドキュメントに書いてあった。。
You can also mark up any class with the @registry() decorator to have the given providers registered upon importing the marked up class. @registry() takes an array of providers like so:
これを実現する通常の方法は、最初の装飾クラスがインスタンス化される前に、プログラムのどこかにDependencyContainer.register()ステートメントを追加することです。
→んなもん、文章から読み解けるかこっちはIQ３０やぞ、約２時間くらい悩んだわ
正しいDI
import 'reflect-metadata';
import { container } from 'tsyringe';
import express from 'express';
import { asyncHandler } from '../middlewares/asyncHandler';
import { FreeeHttpOAuthClient } from '../httpClients/freeeHttpClient';
import { TopController } from '../controllers/top';
import { FreeeController } from '../controllers/freee';
// services
container.register<FreeeHttpOAuthClient>(FreeeHttpOAuthClient, { useValue: new FreeeHttpOAuthClient("YourClientId", "YourClientSecret") });
// controller
const router = express.Router();
const topController = container.resolve(TopController);
const freeeController = container.resolve(FreeeController);
router.get('/', asyncHandler((req, res) => topController.get(req, res)));
router.get('/freee', asyncHandler((req, res) => freeeController.get(req, res)));
export default router;
