javascript - How to use Jest to test functions using crypto or window.msCrypto

Question

When running unit tests with Jest in react the window.crypto API is causing problems. I haven't found a way to incorporate crypto in Jest without installing other packages which is something I can't do. So without using another npm package is there a way to test functions that use: crypto.getRandomValues() in them that doesn't crash Jest? Any links, advice, or tips are appreciated

Answer 1

This should do it. Use the following code to set up the crypto property globally. This will allow Jest to access window.crypto and won't cause any issue.

const crypto = require('crypto');

Object.defineProperty(global.self, 'crypto', {
  value: {
    getRandomValues: arr => crypto.randomBytes(arr.length)
  }
});