axios-cache-interceptor/docs/pages/request-id.md

Request id

A good thing to know is that every request passed through this interceptor, has an id. This does not mean that is a unique id. The id is used in a number of ways, but the most important is to bind a request to its cache.

The id generation is good enough to generate the same id for theoretically sames requests. The example of this is a request with { baseURL: 'https://a.com/', url: '/b' } results to the same id with { url: 'https://a.com/b/' }.

Also, a custom id can be used to treat two requests as the same.

const axios = require('axios');
const { setupCache } = require('axios-cache-interceptor');

// Global
setupCache(axios);

const { id } = await axios.get('https://jsonplaceholder.typicode.com/posts/1', {
  baseURL: 'baseURL',
  query: { name: 'value' }
});

console.log('Id 1: ' + id);
console.log('Cache 1:', await axios.storage.get(id));

const { id: id2 } = await axios.get('https://jsonplaceholder.typicode.com/posts/1', {
  id: 'my-overridden-id'
});

console.log('Id 2: ' + id2);
console.log('Cache 2:', await axios.storage.get(id2));

The default id generation can clarify this idea.

Joining requests

Everything that is used to treat two requests as same or not, is done by the generateKey property.

The value is hashed into a signed integer when the returned value from the provided generator is not a string or a number.

By default, it uses the method, baseURL, params, data and url properties from the request object into an hash code generated by the object-code library.

If you need to change or share the cache for two requests based on other properties, like headers and etc, you can create your own Key Generator:

const axios = require('axios');
const { setupCache, buildKeyGenerator } = require('axios-cache-interceptor');

const generator = buildKeyGenerator(({ headers = {} }) => {
  // In this imaginary example, two requests will
  // be treated as the same if their x-cache-server header is the same.
  return headers['x-cache-server'] || 'not-set';
});

const axios = mockAxios({
  generateKey: keyGenerator
});