index.test.js

const Vue = require('vue');
const VueBus = require('./index');

Vue.use(VueBus);

test('Vue.bus', () => {
  const vm = new Vue({
    data() {
      return { count: 0 };
    },
    created() {
      this.$bus.on('add', num => { this.count += num });
      this.$bus.once('addOnce', num => { this.count += num });
    },
    methods: {
      clean() {
        this.$bus.off('add');
      }
    }
  });

  const obj = {
    fire() {
      Vue.bus.emit('add', 1);
    },
    fireOnce() {
      Vue.bus.emit('addOnce', 1);
    }
  };

  obj.fire();
  expect(vm.count).toBe(1);

  obj.fire();
  expect(vm.count).toBe(2);

  vm.clean();
  obj.fire();
  expect(vm.count).toBe(2);

  obj.fireOnce();
  expect(vm.count).toBe(3);

  obj.fireOnce();
  expect(vm.count).toBe(3);
});

test('this.$bus', () => {
  const vm1 = new Vue({
    data() {
      return { count: 0 };
    },
    created() {
      this.$bus.on('add', num => { this.count += num });
      this.$bus.once('addOnce', num => { this.count += num });
    },
    methods: {
      clean() {
        this.$bus.off('add');
      }
    }
  });

  const vm2 = new Vue({
    methods: {
      fire() {
        this.$bus.emit('add', 1);
      },
      fireOnce() {
        this.$bus.emit('addOnce', 1);
      }
    }
  });

  vm2.fire();
  expect(vm1.count).toBe(1);

  vm2.fire();
  expect(vm1.count).toBe(2);

  vm1.clean();
  vm2.fire();
  expect(vm1.count).toBe(2);

  vm2.fireOnce();
  expect(vm1.count).toBe(3);

  vm2.fireOnce();
  expect(vm1.count).toBe(3);
});