@instructure/quiz-interactions/src/util/__tests__/combinatorics.test.js

A React UI component Library for quiz interaction types.

import {combination, baseNCombination, cartesianProduct, identityMatrix} from '../combinatorics'

describe('Combinatorics', () => {
  describe('combination', () => {
    it('should return a correct matrix for arguments ([0], 0))', () => {
      expect(combination([0], 0)).toEqual([])
    })
    it('should return a correct matrix for arguments ([], 10))', () => {
      expect(combination([], 10)).toEqual([])
    })
    it('should return a correct matrix for arguments ([1], 3)', () => {
      expect(combination([1], 3)).toEqual([[1, 1, 1]])
    })
    it('should return a correct matrix for arguments ([0, 1, 2, 3], 1)', () => {
      expect(combination([0, 1, 2, 3], 1)).toEqual([[0], [1], [2], [3]])
    })
    it('should return a correct matrix for arguments ([0, 1], 2)', () => {
      expect(combination([0, 1], 2)).toEqual([
        [0, 0],
        [0, 1],
        [1, 1],
      ])
    })
    it('should return a correct matrix for arguments ([0, 1], 3)', () => {
      expect(combination([0, 1], 3)).toEqual([
        [0, 0, 0],
        [0, 0, 1],
        [0, 1, 1],
        [1, 1, 1],
      ])
    })
    it('should return a correct matrix for arguments ([0, 1, 2], 3)', () => {
      expect(combination([0, 1, 2], 3)).toEqual([
        [0, 0, 0],
        [0, 0, 1],
        [0, 0, 2],
        [0, 1, 1],
        [0, 1, 2],
        [0, 2, 2],
        [1, 1, 1],
        [1, 1, 2],
        [1, 2, 2],
        [2, 2, 2],
      ])
    })
  })

  describe('baseNCombination', () => {
    it('should return a correct matrix for arguments ([0], 0))', () => {
      expect(baseNCombination([0], 0)).toEqual([])
    })
    it('should return a correct matrix for arguments ([], 10))', () => {
      expect(baseNCombination([], 10)).toEqual([])
    })
    it('should return a correct matrix for arguments ([1], 3))', () => {
      expect(baseNCombination([1], 3)).toEqual([[1, 1, 1]])
    })
    it('should return a correct matrix for arguments ([0, 1, 2, 3], 1))', () => {
      expect(baseNCombination([0, 1, 2, 3], 1)).toEqual([[0], [1], [2], [3]])
    })
    it('should return a correct matrix for arguments ([0, 1], 2))', () => {
      expect(baseNCombination([0, 1], 2)).toEqual([
        [0, 0],
        [0, 1],
        [1, 0],
        [1, 1],
      ])
    })
    it('should return a correct matrix for arguments ([0, 1], 3))', () => {
      expect(baseNCombination([0, 1], 3)).toEqual([
        [0, 0, 0],
        [0, 0, 1],
        [0, 1, 0],
        [0, 1, 1],
        [1, 0, 0],
        [1, 0, 1],
        [1, 1, 0],
        [1, 1, 1],
      ])
    })
    it('should return a correct matrix for arguments ([0, 1, 2], 3))', () => {
      expect(baseNCombination([0, 1, 2], 3)).toEqual([
        [0, 0, 0],
        [0, 0, 1],
        [0, 0, 2],
        [0, 1, 0],
        [0, 1, 1],
        [0, 1, 2],
        [0, 2, 0],
        [0, 2, 1],
        [0, 2, 2],
        [1, 0, 0],
        [1, 0, 1],
        [1, 0, 2],
        [1, 1, 0],
        [1, 1, 1],
        [1, 1, 2],
        [1, 2, 0],
        [1, 2, 1],
        [1, 2, 2],
        [2, 0, 0],
        [2, 0, 1],
        [2, 0, 2],
        [2, 1, 0],
        [2, 1, 1],
        [2, 1, 2],
        [2, 2, 0],
        [2, 2, 1],
        [2, 2, 2],
      ])
    })
  })

  describe('cartesianProduct', () => {
    it('should return a correct product for arguments ([], [])).', () => {
      expect(cartesianProduct([], [])).toEqual([])
    })

    it('should return a correct product for arguments ([1], [])).t', () => {
      expect(cartesianProduct([1], [])).toEqual([])
    })

    it("should return a correct product for arguments ([1, 2], ['a', 'b'])", () => {
      expect(cartesianProduct([1, 2], ['a', 'b'])).toEqual([
        [1, 'a'],
        [1, 'b'],
        [2, 'a'],
        [2, 'b'],
      ])
    })

    it("should return a correct product for arguments ([1, 2], ['a', 'b'])", () => {
      expect(cartesianProduct([1, 2], ['a', 'b'])).toEqual([
        [1, 'a'],
        [1, 'b'],
        [2, 'a'],
        [2, 'b'],
      ])
    })

    it("should return a correct product for arguments ([1], ['a', 'b', 'c'])", () => {
      expect(cartesianProduct([1], ['a', 'b', 'c'])).toEqual([
        [1, 'a'],
        [1, 'b'],
        [1, 'c'],
      ])
    })

    it("should return a correct product for arguments ([0, 1], ['a', 'b', 'c'])", () => {
      expect(cartesianProduct([0, 1], ['a', 'b', 'c'])).toEqual([
        [0, 'a'],
        [0, 'b'],
        [0, 'c'],
        [1, 'a'],
        [1, 'b'],
        [1, 'c'],
      ])
    })

    it("should return a correct product for arguments ([0, 1], ['a', 'b'], [5, 6])", () => {
      expect(cartesianProduct([0, 1], ['a', 'b'], [5, 6])).toEqual([
        [0, 'a', 5],
        [0, 'a', 6],
        [0, 'b', 5],
        [0, 'b', 6],
        [1, 'a', 5],
        [1, 'a', 6],
        [1, 'b', 5],
        [1, 'b', 6],
      ])
    })
  })

  describe('identityMatrix', () => {
    it('should return a correct identity for arguments ([0, 1], 1)', () => {
      expect(identityMatrix([1, 0], 1)).toEqual([[1]])
    })

    it('should return a correct product for arguments ([1, 0], 0)).', () => {
      expect(identityMatrix([1, 0], 0)).toEqual([])
    })

    it('should return a correct product for arguments ([1, 0], 2)).', () => {
      expect(identityMatrix([1, 0], 2)).toEqual([
        [1, 0],
        [0, 1],
      ])
    })

    it('should have default arguments', () => {
      expect(identityMatrix([], 2)).toEqual([
        [1, 0],
        [0, 1],
      ])
    })

    it('should return a correct product for arguments ([4, 10], 3)).', () => {
      expect(identityMatrix([4, 10], 3)).toEqual([
        [4, 10, 10],
        [10, 4, 10],
        [10, 10, 4],
      ])
    })

    it("should return a correct product for arguments ([null, 'NULL'], 4)).", () => {
      expect(identityMatrix([null, 'NULL'], 4)).toEqual([
        [null, 'NULL', 'NULL', 'NULL'],
        ['NULL', null, 'NULL', 'NULL'],
        ['NULL', 'NULL', null, 'NULL'],
        ['NULL', 'NULL', 'NULL', null],
      ])
    })
  })
})