Learning Redux

Testing initial state

We start by writing a test for the initial state:

1. Edit __tests__/reducers/filter.test.js and define the test function:

test('initial state should be false (no filter)', () => {

2. To initialize the reducer, we pass undefined as the state (first argument) and an empty object as the action (second argument):

  const state = filterReducer(undefined, {})

3. Now, we check the initial state of the reducer:

  expect(state).toBe(false)})