import { factorial } from '../Factorial'

describe('Factorial', () => {

it('should return factorial 1 for value "0"', () => {

expect(factorial(0)).toBe(1)

})

it('should return factorial 120 for value "5"', () => {

expect(factorial(5)).toBe(120)

})

it('Throw Error for Invalid Input', () => {

expect(() => factorial('-')).toThrow(

'Input should be a non-negative whole number'

)

expect(() => factorial(null)).toThrow(

'Input should be a non-negative whole number'

)

expect(() => factorial(undefined)).toThrow(

'Input should be a non-negative whole number'

)

expect(() => factorial(3.142)).toThrow(

'Input should be a non-negative whole number'

)

expect(() => factorial(-1)).toThrow(

'Input should be a non-negative whole number'

)

})

})