server.test.js

// ava is a test runner for Node.js that isolates tests
const test = require('ava');
// micro is a minimal http framework (what's run by `npm start`)
const micro = require('micro');
// test-listen creates URLs with ephimeral ports ideal for isolated tests
const listen = require('test-listen');
// node-fetch brings window.fetch to Node.js
const fetch = require('node-fetch');

const main = require('.');

// serveStatic
[
  ['/', /Quickstart/],
  ['/index.html', /sandbox\.web\.squarecdn/],
  ['/favicon.ico', /.+/],
].forEach(([path, re]) => {
  test(`serves ${path}`, async (t) => {
    const service = micro(main);
    const url = await listen(service);
    const res = await fetch(url + path);
    t.true(res.ok);

    const body = await res.text();
    t.regex(body, re);

    service.close(t.falsy);
  });
});

// createPayment
test('createPayment errors with invalid payload', async (t) => {
  const service = micro(main);
  const url = await listen(service);
  const res = await fetch(`${url}/payment`, {
    method: 'post',
    headers: { 'Content-Type': 'application/json' },
    body: JSON.stringify({
      wrong: true,
    }),
  });

  // expect 'bad request' response because body is wrong (literally)
  t.false(res.ok);
  t.is(res.status, 400);

  service.close(t.falsy);
});

// storeCard
test('storeCard errors with invalid payload', async (t) => {
  const service = micro(main);
  const url = await listen(service);
  const res = await fetch(`${url}/card`, {
    method: 'post',
    headers: { 'Content-Type': 'application/json' },
    body: JSON.stringify({
      wrong: true,
    }),
  });

  // expect 'bad request' response because body is wrong (literally)
  t.false(res.ok);
  t.is(res.status, 400);

  service.close(t.falsy);
});