Test npm scripts in package.json (WIP)

npm-script.test.js

const util = require('util');
const exec = util.promisify(require('child_process').exec);
const fetch = require('undici').fetch;
const promiseRetry = require('promise-retry');

const sleep = (time) => {
  return new Promise((resolve, reject) => {
      setTimeout(() => {
          resolve()
      }, time)
  })
}

describe('npm scripts', () => {
  it.concurrent('starts a dev server', async () => {
    const ac = new AbortController();
    const devServerPromise = exec('npm run dev', { signal: ac.signal });
    const result = await promiseRetry(async (retry, number) => {
      if (number > 1) {
        console.log(`Retrying fetch...(${number})`);
      }
      try {
        console.log(`Let's try (${number}th time)`);
        return await fetch('http://localhost:3000/')
      } catch (e) {
        await sleep(1000);
        await retry(e);
      }
    }, { retries: 10 });
    console.log('After promiseRetry()');
    try {
      ac.abort();
    } catch (e) {
      console.log("abort 例外を無視 ", e);
    }
    expect(result.status).toBe(200);
  });
});