Business
Jobs
  • About Us
  • Solutions
    • Job Postings
      Post your job and receive qualified candidates in 48h.
    • Candidate Assessments
      500+ technical and psychological tests, plus anti-fraud.
    • Headhunting
      Tailor-made executive search from start to finish.
    • Payroll + EOR
      Payroll dispersal and EOR across 15+ LATAM countries.
  • Pricing
  • Jobs

0

77
Views
Overwriting a module import for mocking during tests?

I am writing unit tests and would like to mock a function in a module but avoid using jest.mock. Is such a thing possible?

If not, how does jest.mock work and will it survive the transition from commonjs to esmodules in Node?

import * as foo from './foo'

describe('foo', () => {
  let mockFn: jest.Mock

  beforeEach(() => {
    mockFn = jest.fn()
    
    Object.defineProperty(foo, 'bar', {
      value: mockFn,
      writable: true,
      configurable: true,
    })
  })

  it('Should not throw', () => {
    const testFunc = () => foo()
    expect(testFunc).not.toThrow()
  })
})
about 4 years ago · Juan Pablo Isaza
Answer question
Find remote jobs

Discover the new way to find a job!

Top jobs
Top job categories
Business
Post vacancy Pricing Sales
Legal
Terms and conditions Privacy policy
© 2026 PeakU Inc. All Rights Reserved.
Andres GPT
Show me some job opportunities
There's an error!