vue/test/unit/features/options/data.spec.js

import Vue from 'vue'

describe('Options data', () => {
  it('should proxy and be reactive', done => {
    const data = { msg: 'foo' }
    const vm = new Vue({
      data,
      template: '<div>{{ msg }}</div>'
    }).$mount()
    expect(vm.$data).toEqual({ msg: 'foo' })
    expect(vm.$data).toBe(data)
    data.msg = 'bar'
    waitForUpdate(() => {
      expect(vm.$el.textContent).toBe('bar')
    }).then(done)
  })

  it('should merge data properly', () => {
    const Test = Vue.extend({
      data () {
        return { a: 1 }
      }
    })
    let vm = new Test({
      data: { b: 2 }
    })
    expect(vm.a).toBe(1)
    expect(vm.b).toBe(2)
    // no instance data
    vm = new Test()
    expect(vm.a).toBe(1)
    // no child-val
    const Extended = Test.extend({})
    vm = new Extended()
    expect(vm.a).toBe(1)
    // recursively merge objects
    const WithObject = Vue.extend({
      data () {
        return {
          obj: {
            a: 1
          }
        }
      }
    })
    vm = new WithObject({
      data: {
        obj: {
          b: 2
        }
      }
    })
    expect(vm.obj.a).toBe(1)
    expect(vm.obj.b).toBe(2)
  })

  it('should warn non-function during extend', () => {
    Vue.extend({
      data: { msg: 'foo' }
    })
    expect('The "data" option should be a function').toHaveBeenWarned()
  })

  it('should warn non object return', () => {
    new Vue({
      data () {}
    })
    expect('data functions should return an object').toHaveBeenWarned()
  })

  it('should warn replacing root $data', () => {
    const vm = new Vue({
      data: {}
    })
    vm.$data = {}
    expect('Avoid replacing instance root $data').toHaveBeenWarned()
  })

  it('should have access to props', () => {
    const Test = {
      props: ['a'],
      render () {},
      data () {
        return {
          b: this.a
        }
      }
    }
    const vm = new Vue({
      template: `<test ref="test" :a="1"></test>`,
      components: { Test }
    }).$mount()
    expect(vm.$refs.test.b).toBe(1)
  })

  it('props should not be reactive', done => {
    let calls = 0
    const vm = new Vue({
      template: `<child :msg="msg"></child>`,
      data: {
        msg: 'hello'
      },
      beforeUpdate () { calls++ },
      components: {
        child: {
          template: `<span>{{ localMsg }}</span>`,
          props: ['msg'],
          data () {
            return { localMsg: this.msg }
          },
          computed: {
            computedMsg () {
              return this.msg + ' world'
            }
          }
        }
      }
    }).$mount()
    const child = vm.$children[0]
    vm.msg = 'hi'
    waitForUpdate(() => {
      expect(child.localMsg).toBe('hello')
      expect(child.computedMsg).toBe('hi world')
      expect(calls).toBe(1)
    }).then(done)
  })

  it('should have access to methods', () => {
    const vm = new Vue({
      methods: {
        get () {
          return { a: 1 }
        }
      },
      data () {
        return this.get()
      }
    })
    expect(vm.a).toBe(1)
  })

  it('should be called with this', () => {
    const vm = new Vue({
      template: '<div><child></child></div>',
      provide: { foo: 1 },
      components: {
        child: {
          template: '<span>{{bar}}</span>',
          inject: ['foo'],
          data ({ foo }) {
            return { bar: 'foo:' + foo }
          }
        }
      }
    }).$mount()
    expect(vm.$el.innerHTML).toBe('<span>foo:1</span>')
  })

  it('should be called with vm as first argument when merged', () => {
    const superComponent = {
      data: ({ foo }) => ({ ext: 'ext:' + foo })
    }
    const mixins = [
      {
        data: ({ foo }) => ({ mixin1: 'm1:' + foo })
      },
      {
        data: ({ foo }) => ({ mixin2: 'm2:' + foo })
      }
    ]
    const vm = new Vue({
      template: '<div><child></child></div>',
      provide: { foo: 1 },
      components: {
        child: {
          extends: superComponent,
          mixins,
          template: '<span>{{bar}}-{{ext}}-{{mixin1}}-{{mixin2}}</span>',
          inject: ['foo'],
          data: ({ foo }) => ({ bar: 'foo:' + foo })
        }
      }
    }).$mount()
    expect(vm.$el.innerHTML).toBe('<span>foo:1-ext:1-m1:1-m2:1</span>')
  })
})