medium-polly-intercept-example.js

/*
  Create a new polly instance.
  
  Connect Polly to fetch. By default, it will record any requests that it 
  hasn't yet seen while replaying ones it has already recorded.
*/
const polly = new Polly('Simple Example', {
  adapters: ['fetch'], // Hook into `fetch`
  persister: 'local-storage', // Read/write to/from local-storage
});

const { server } = polly;

/* Use the client-side server to intercept all requests to /posts/:id */
server.get('/posts/:id').intercept((req, res) => {
  const { id } = req.params;

  /* Respond with our own custom json object */
  res
    .status(200)
    .json({ id, title: `Post ${id}`, body: '👋 𝐌edium' });
});

/* Any networks requests here using fetch will be handled by the Polly instance. */
await fetch('/posts/1');

/* Calling `stop` will persist requests as well as disconnect from any connected adapters. */
await polly.stop();