TypeScript Version: 3.9.2, 3.9.3

Search Terms: sinon, stub

Code

// file: ./src/stubber/index.ts
export { toStub } from './to-stub'

// file: ./src/stubber/to-stub.ts
export const toStub = () => {
  console.log('real stub')
}

// file: ./src/start.ts
import * as sinon from 'sinon'
import * as stubber from './stubber'
(async () => {
  sinon.stub(stubber, 'toStub').callsFake(() => {
    console.log('fake stub')
  })
  stubber.toStub()
})()

Run the start.ts script by compiling it with tsc or simply use ts-node.
I'd expect it print fake stub but now it prints real stub. It's working as expected for typescript@3.8 or lower, start breaking from 3.9.2.

Expected behavior:

Print "fake stub"

Actual behavior:

Print "real stub"

Playground Link: Can't provide Playground link because it contains multiple files

Related Issues: Nope