core/packages/observer/__tests__/collections/WeakSet.spec.ts

import { observable, isObservable, autorun, unwrap } from '../../src'

describe('observer/collections', () => {
  describe('WeakSet', () => {
    it('instanceof', () => {
      const original = new Set()
      const observed = observable(original)
      expect(isObservable(observed)).toBe(true)
      expect(original instanceof Set).toBe(true)
      expect(observed instanceof Set).toBe(true)
    })

    it('should observe mutations', () => {
      let dummy
      const value = {}
      const set = observable(new WeakSet())
      autorun(() => (dummy = set.has(value)))

      expect(dummy).toBe(false)
      set.add(value)
      expect(dummy).toBe(true)
      set.delete(value)
      expect(dummy).toBe(false)
    })

    it('should not observe custom property mutations', () => {
      let dummy
      const set: any = observable(new WeakSet())
      autorun(() => (dummy = set.customProp))

      expect(dummy).toBe(undefined)
      set.customProp = 'Hello World'
      expect(dummy).toBe(undefined)
    })

    it('should not observe non value changing mutations', () => {
      let dummy
      const value = {}
      const set = observable(new WeakSet())
      const setSpy = jest.fn(() => (dummy = set.has(value)))
      autorun(setSpy)

      expect(dummy).toBe(false)
      expect(setSpy).toHaveBeenCalledTimes(1)
      set.add(value)
      expect(dummy).toBe(true)
      expect(setSpy).toHaveBeenCalledTimes(2)
      set.add(value)
      expect(dummy).toBe(true)
      expect(setSpy).toHaveBeenCalledTimes(2)
      set.delete(value)
      expect(dummy).toBe(false)
      expect(setSpy).toHaveBeenCalledTimes(3)
      set.delete(value)
      expect(dummy).toBe(false)
      expect(setSpy).toHaveBeenCalledTimes(3)
    })

    it('should not observe raw data', () => {
      const value = {}
      let dummy
      const set = observable(new WeakSet())
      autorun(() => (dummy = unwrap(set).has(value)))

      expect(dummy).toBe(false)
      set.add(value)
      expect(dummy).toBe(false)
    })

    it('should not be triggered by raw mutations', () => {
      const value = {}
      let dummy
      const set = observable(new WeakSet())
      autorun(() => (dummy = set.has(value)))

      expect(dummy).toBe(false)
      unwrap(set).add(value)
      expect(dummy).toBe(false)
    })

    it('should not pollute original Set with Proxies', () => {
      const set = new WeakSet()
      const observed = observable(set)
      const value = observable({})
      observed.add(value)
      expect(observed.has(value)).toBe(true)
      expect(set.has(value)).toBe(false)
    })
  })
})