service-tester

This module makes it easier for you to write tests for your node.js GasBuddy microservice. Simply add the module as a dev dependency:

yarn add -D @gasbuddy/service-tester

Then write a test in /__tests__/startup.test.js:

import request from 'supertest';
import { getReusableApp, clearReusableApp } from '@gasbuddy/service-tester';
import myService from '../src/index';

describe('my service', () => {
  test('should start', async () => {
    const app = await getReusableApp(myService);
    expect(app).toBeTruthy();
    await request(app).get('/').expect(200);
  });
});

Service call mocking

Nock is so 2010. The future is mock! Since we have typed clients for services these days, mocking them is easier. We've played some nutty tricks with Typescript (well, nutty for me), to enable this kind of syntax:

  mockServiceCall(app.locals.services.myCrazyServ, 'get_some_resource').mockResolvedValue({
    status: 200,
    responseType: 'response',
    body: { resource: true },
    headers: new Headers(),
  });

This will cause calls to app.locals.services.myCrazyServ.get_some_resource() to return {resource: true}. This is just shorthand for jest.spyOn(service, 'method') with knowledge of the traditional return type of OpenAPI service calls.

Web apps

The exported jestConfig is ts-node-based, which suits API/job services but doesn't fit web apps that run through Babel (JSX, CSS modules, @loadable/component). For those, use webJestConfig instead — it's a babel-jest two-project config with a unit project (jsdom, for component tests co-located under src/) and an integration project (node, for SSR/service-boot tests under tests/), and it maps static asset imports (.svg/.png/.jpe?g/.gif) to a stub so component tests don't need a real file-loader.

// jest.config.js
module.exports = require('@gasbuddy/service-tester').webJestConfig;

Each project is also exported individually (webJestUnitProjectConfig, webJestIntegrationProjectConfig) so an app can override or extend just one of them:

// jest.config.js
const {
  webJestUnitProjectConfig,
  webJestIntegrationProjectConfig,
} = require('@gasbuddy/service-tester');

module.exports = {
  projects: [
    { ...webJestUnitProjectConfig, setupFilesAfterEnv: ['<rootDir>/tests/setup.ts'] },
    webJestIntegrationProjectConfig,
  ],
};

Run either config through gb-jest the same way as the ts-node-based jestConfig.