import actions from 'background/actions'; import tabReducer from 'background/reducers/tab'; describe("tab reducer", () => { it('return the initial state', () => { let state = tabReducer(undefined, {}); expect(state.previousSelected).to.equal(-1); expect(state.currentSelected).to.equal(-1); }); it('return next state for TAB_SELECTED', () => { let state = undefined; state = tabReducer(state, { type: actions.TAB_SELECTED, tabId: 123 }); expect(state.previousSelected).to.equal(-1); expect(state.currentSelected).to.equal(123); state = tabReducer(state, { type: actions.TAB_SELECTED, tabId: 456 }); expect(state.previousSelected).to.equal(123); expect(state.currentSelected).to.equal(456); }); });