Sep 7, 2022 · Sep 6, 2022 · Sep 6, 2022 · Sep 6, 2022
diff --git a/Maths/Factorial.js b/Maths/Factorial.js

 const calcFactorial = (num) => {
  if (num === 0) {
    return'The factorial of 0 is 1.'
    return1
  }
  if (num < 0) {
 return'Sorry, factorial does not exist for negative numbers.'
 throw Error('Sorry, factorial does not exist for negative numbers.')
  }
  if (!num) {
 return'Sorry, factorial does not exist for null or undefined numbers.'
 throw Error('Sorry, factorial does not exist for null or undefined numbers.')
  }
  if (num > 0) {
    const range = calcRange(num)
    const factorial = range.reduce((a, c) => a * c, 1)
    return`Thefactorial of ${num} is ${factorial}`
    return factorial
  }
 }

diff --git a/Maths/test/Factorial.test.js b/Maths/test/Factorial.test.js

 describe('calcFactorial', () => {
  it('should return a statement for value "0"', () => {
    expect(calcFactorial(0)).toBe('The factorial of 0 is 1.')
    expect(calcFactorial(0)).toBe(1)
  })

  it('should return a statement for "null" and "undefined"', () => {
    const nullFactorial = calcFactorial(null)
    const undefinedFactorial = calcFactorial(undefined)

    expect(nullFactorial).toBe(
      'Sorry, factorial does not exist for null or undefined numbers.'
    )
    expect(undefinedFactorial).toBe(
      'Sorry, factorial does not exist for null or undefined numbers.'
    )
  it('should throw error for "null" and "undefined"', () => {
    expect(() => { calcFactorial(null) }).toThrow(Error)
    expect(() => { calcFactorial(undefined) }).toThrow(Error)
  })

  it('should not support negative numbers', () => {
    const negativeFactorial = calcFactorial(-5)
    expect(negativeFactorial).toBe(
      'Sorry, factorial does not exist for negative numbers.'
    )
  it('should throw error for negative numbers', () => {
    expect(() => { calcFactorial(-1) }).toThrow(Error)
  })

  it('should return the factorial of a positive number', () => {
    const positiveFactorial = calcFactorial(3)
    expect(positiveFactorial).toBe('The factorial of 3 is 6')
    expect(positiveFactorial).toBe(6)
  })
 })
Original file line number	Diff line number	Diff line change
Expand Up		@@ -19,18 +19,18 @@ const calcRange = (num) => {

		const calcFactorial = (num) => {
		if (num === 0) {
		return'The factorial of 0 is 1.'
		return1
		}
		if (num < 0) {
		return'Sorry, factorial does not exist for negative numbers.'
		throw Error('Sorry, factorial does not exist for negative numbers.')
		}
		if (!num) {
		return'Sorry, factorial does not exist for null or undefined numbers.'
		throw Error('Sorry, factorial does not exist for null or undefined numbers.')
		}
		if (num > 0) {
		const range = calcRange(num)
		const factorial = range.reduce((a, c) => a * c, 1)
		return`Thefactorial of ${num} is ${factorial}`
		return factorial
		}
		}

Expand Down
Original file line number	Diff line number	Diff line change
Expand Up		@@ -2,30 +2,20 @@ import { calcFactorial } from '../Factorial'

		describe('calcFactorial', () => {
		it('should return a statement for value "0"', () => {
		expect(calcFactorial(0)).toBe('The factorial of 0 is 1.')
		expect(calcFactorial(0)).toBe(1)
		})

		it('should return a statement for "null" and "undefined"', () => {
		const nullFactorial = calcFactorial(null)
		const undefinedFactorial = calcFactorial(undefined)

		expect(nullFactorial).toBe(
		'Sorry, factorial does not exist for null or undefined numbers.'
		)
		expect(undefinedFactorial).toBe(
		'Sorry, factorial does not exist for null or undefined numbers.'
		)
		it('should throw error for "null" and "undefined"', () => {
		expect(() => { calcFactorial(null) }).toThrow(Error)
		expect(() => { calcFactorial(undefined) }).toThrow(Error)
		})

		it('should not support negative numbers', () => {
		const negativeFactorial = calcFactorial(-5)
		expect(negativeFactorial).toBe(
		'Sorry, factorial does not exist for negative numbers.'
		)
		it('should throw error for negative numbers', () => {
		expect(() => { calcFactorial(-1) }).toThrow(Error)
		})

		it('should return the factorial of a positive number', () => {
		const positiveFactorial = calcFactorial(3)
		expect(positiveFactorial).toBe('The factorial of 3 is 6')
		expect(positiveFactorial).toBe(6)
		})
		})