// __tests__/example.js jest.mock('fs'); it('should serve as a nice example', () => { const fs = require('fs') // fs can be set up at any point by calling __configureFs. fs.__configureFs({ '/test': { 'a.foo': '----', // mock-fs' other exports are also available on the fs object. 'b.bar': fs.__mockFile({ content: 'file content here', ctime: new Date(1), mtime: new Date(1) }), }) const results = fs.readdirSync('/test') expect(results.length).toBe(2) expect(results).toEqual(['a.foo', 'b.bar']) })