@cc-heart/utils/__test__/src/hooks/useOnce.test.ts

🔧 javascript common tools collection

import { useOnce } from '../../../hooks'

describe('useOnce module', () => {
  it('should return a function', () => {
    const fn = useOnce(() => null)
    expect(fn instanceof Function).toBeTruthy()
  })

  it('throw error when params is not a function', () => {
    // eslint-disable-next-line @typescript-eslint/ban-ts-comment
    // @ts-ignore
    const fn = () => useOnce('')
    expect(fn).toThrowError('first params must be a function')
  })

  it('It should only be executed once when it is called multiple times', () => {
    const mockFn = jest.fn((num1: number, num2: number) => num1 + num2)
    const fn = useOnce(() => mockFn(1, 2))
    for (let i = 0; i < 3; i++) {
      fn()
    }
    expect(mockFn.mock.calls.length).toBe(1)
  })
})