jest test async code

March - 2022

Notes

  • Add async to the function that gets passed to the test
  • Use await when calling the function under test
  • Make the function under test async
  • Add await as necessary in the function under test

Test file

const sum = require('./sum')

test('adds 1 + 2 to equal 3', async () => {
  const result = await sum(1, 2)
  expect(result).toBe(3)
})

File under test

async function sum(a, b) {
  // do some 'await' stuff here
  return a + b
}

module.exports = sum