computed.spec.ts — vue Source File

Source Code

import {
  computed,
  reactive,
  ref,
  isReadonly,
  WritableComputedRef,
  DebuggerEvent,
  TrackOpTypes,
  TriggerOpTypes
} from 'v3'
import { effect } from 'v3/reactivity/effect'
import { nextTick } from 'core/util'
import { set, del } from 'core/observer/index'

describe('reactivity/computed', () => {
  it('should return updated value', () => {
    const value = reactive({ foo: 1 })
    const cValue = computed(() => value.foo)
    expect(cValue.value).toBe(1)
    value.foo = 2
    expect(cValue.value).toBe(2)
  })

  it('should compute lazily', () => {
    const value = reactive<{ foo?: number }>({ foo: undefined })
    const getter = vi.fn(() => value.foo)
    const cValue = computed(getter)

    // lazy
    expect(getter).not.toHaveBeenCalled()

    expect(cValue.value).toBe(undefined)
    expect(getter).toHaveBeenCalledTimes(1)

    // should not compute again
    cValue.value
    expect(getter).toHaveBeenCalledTimes(1)

    // should not compute until needed
    value.foo = 1
    expect(getter).toHaveBeenCalledTimes(1)

    // now it should compute
    expect(cValue.value).toBe(1)
    expect(getter).toHaveBeenCalledTimes(2)

    // should not compute again
    cValue.value
    expect(getter).toHaveBeenCalledTimes(2)
  })

  it('should trigger effect', () => {
    const value = reactive<{ foo?: number }>({ foo: undefined })
    const cValue = computed(() => value.foo)
    let dummy
    effect(() => {
      dummy = cValue.value
    })
    expect(dummy).toBe(undefined)
    value.foo = 1
// ... (242 more lines)