mathjs/test/unit-tests/function/arithmetic/gcd.test.js

// test gcd
import assert from 'assert'

import math from '../../../../src/defaultInstance.js'
const matrix = math.matrix
const sparse = math.sparse
const gcd = math.gcd

describe('gcd', function () {
  it('should find the greatest common divisor of two or more numbers', function () {
    assert.strictEqual(gcd(12, 8), 4)
    assert.strictEqual(gcd(8, 12), 4)
    assert.strictEqual(gcd(8, -12), 4)
    assert.strictEqual(gcd(-12, 8), 4)
    assert.strictEqual(gcd(12, -8), 4)
    assert.strictEqual(gcd(15, 3), 3)
    assert.strictEqual(gcd(25, 15, -10, 30), 5)
  })

  it('should calculate gcd for edge cases around zero', function () {
    assert.strictEqual(gcd(3, 0), 3)
    assert.strictEqual(gcd(-3, 0), 3)
    assert.strictEqual(gcd(0, 3), 3)
    assert.strictEqual(gcd(0, -3), 3)
    assert.strictEqual(gcd(0, 0), 0)

    assert.strictEqual(gcd(1, 1), 1)
    assert.strictEqual(gcd(1, 0), 1)
    assert.strictEqual(gcd(1, -1), 1)
    assert.strictEqual(gcd(-1, 1), 1)
    assert.strictEqual(gcd(-1, 0), 1)
    assert.strictEqual(gcd(-1, -1), 1)
    assert.strictEqual(gcd(0, 1), 1)
    assert.strictEqual(gcd(0, -1), 1)
    assert.strictEqual(gcd(0, 0), 0)
  })

  it('should calculate gcd for edge cases with negative values', function () {
    assert.deepStrictEqual(1, gcd(2, 5))
    assert.deepStrictEqual(1, gcd(2, -5))
    assert.deepStrictEqual(1, gcd(-2, 5))
    assert.deepStrictEqual(1, gcd(-2, -5))

    assert.deepStrictEqual(2, gcd(2, 6))
    assert.deepStrictEqual(2, gcd(2, -6))
    assert.deepStrictEqual(2, gcd(-2, 6))
    assert.deepStrictEqual(2, gcd(-2, -6))
  })

  it('should calculate gcd for BigNumbers', function () {
    assert.deepStrictEqual(gcd(math.bignumber(12), math.bignumber(8)), math.bignumber(4))
    assert.deepStrictEqual(gcd(math.bignumber(8), math.bignumber(12)), math.bignumber(4))
  })

  it('should calculate gcd for mixed BigNumbers and Numbers', function () {
    assert.deepStrictEqual(gcd(math.bignumber(12), 8), math.bignumber(4))
    assert.deepStrictEqual(gcd(8, math.bignumber(12)), math.bignumber(4))
  })

  it('should find the greatest common divisor of fractions', function () {
    const a = math.fraction(5, 8)
    assert.strictEqual(gcd(a, math.fraction(3, 7)).toString(), '0.017(857142)')
    assert.strictEqual(a.toString(), '0.625')
  })

  it('should find the greatest common divisor of mixed numbers and fractions', function () {
    assert.deepStrictEqual(gcd(math.fraction(12), 8), math.fraction(4))
    assert.deepStrictEqual(gcd(12, math.fraction(8)), math.fraction(4))
  })

  it('should find the greatest common divisor of booleans', function () {
    assert.strictEqual(gcd(true, true), 1)
    assert.strictEqual(gcd(true, false), 1)
    assert.strictEqual(gcd(false, true), 1)
    assert.strictEqual(gcd(false, false), 0)
  })

  it('should throw an error if only one argument', function () {
    assert.throws(function () { gcd(1) }, /TypeError: Too few arguments/)
  })

  it('should throw an error for non-integer numbers', function () {
    assert.throws(function () { gcd(2, 4.1) }, /Parameters in function gcd must be integer numbers/)
    assert.throws(function () { gcd(2.3, 4) }, /Parameters in function gcd must be integer numbers/)
  })

  it('should throw an error with complex numbers', function () {
    assert.throws(function () { gcd(math.complex(1, 3), 2) }, /TypeError: Unexpected type of argument/)
  })

  it('should convert strings to numbers', function () {
    assert.strictEqual(gcd('12', '8'), 4)
    assert.strictEqual(gcd(12, '8'), 4)
    assert.strictEqual(gcd('12', 8), 4)

    assert.throws(function () { gcd('a', 8) }, /Cannot convert "a" to a number/)
  })

  it('should throw an error with units', function () {
    assert.throws(function () { gcd(math.unit('5cm'), 2) }, /TypeError: Unexpected type of argument/)
  })

  describe('Array', function () {
    it('should find the greatest common divisor array - scalar', function () {
      assert.deepStrictEqual(gcd([5, 18, 3], 3), [1, 3, 3])
      assert.deepStrictEqual(gcd(3, [5, 18, 3]), [1, 3, 3])
    })

    it('should find the greatest common divisor array - array', function () {
      assert.deepStrictEqual(gcd([5, 2, 3], [25, 3, 6]), [5, 1, 3])
    })

    it('should find the greatest common divisor array - dense matrix', function () {
      assert.deepStrictEqual(gcd([5, 2, 3], matrix([25, 3, 6])), matrix([5, 1, 3]))
    })

    it('should find the greatest common divisor array - sparse matrix', function () {
      assert.deepStrictEqual(gcd([[5, 2, 3], [3, 2, 5]], sparse([[0, 3, 6], [6, 0, 25]])), matrix([[5, 1, 3], [3, 2, 5]]))
    })
  })

  describe('DenseMatrix', function () {
    it('should find the greatest common divisor dense matrix - scalar', function () {
      assert.deepStrictEqual(gcd(matrix([5, 18, 3]), 3), matrix([1, 3, 3]))
      assert.deepStrictEqual(gcd(3, matrix([5, 18, 3])), matrix([1, 3, 3]))
    })

    it('should find the greatest common divisor dense matrix - array', function () {
      assert.deepStrictEqual(gcd(matrix([5, 2, 3]), [25, 3, 6]), matrix([5, 1, 3]))
    })

    it('should find the greatest common divisor dense matrix - dense matrix', function () {
      assert.deepStrictEqual(gcd(matrix([5, 2, 3]), matrix([25, 3, 6])), matrix([5, 1, 3]))
    })

    it('should find the greatest common divisor dense matrix - sparse matrix', function () {
      assert.deepStrictEqual(gcd(matrix([[5, 2, 3], [3, 2, 5]]), sparse([[0, 3, 6], [6, 0, 25]])), matrix([[5, 1, 3], [3, 2, 5]]))
    })
  })

  describe('SparseMatrix', function () {
    it('should find the greatest common divisor sparse matrix - scalar', function () {
      assert.deepStrictEqual(gcd(sparse([[5, 0, 3], [0, 18, 0]]), 3), matrix([[1, 3, 3], [3, 3, 3]]))
      assert.deepStrictEqual(gcd(3, sparse([[5, 0, 3], [0, 18, 0]])), matrix([[1, 3, 3], [3, 3, 3]]))
    })

    it('should find the greatest common divisor sparse matrix - array', function () {
      assert.deepStrictEqual(gcd(sparse([[5, 2, 3], [3, 2, 5]]), [[0, 3, 6], [6, 0, 25]]), matrix([[5, 1, 3], [3, 2, 5]]))
    })

    it('should find the greatest common divisor sparse matrix - dense matrix', function () {
      assert.deepStrictEqual(gcd(sparse([[5, 2, 3], [3, 2, 5]]), matrix([[0, 3, 6], [6, 0, 25]])), matrix([[5, 1, 3], [3, 2, 5]]))
    })

    it('should find the greatest common divisor sparse matrix - sparse matrix', function () {
      assert.deepStrictEqual(gcd(sparse([[5, 2, 3], [3, 2, 5]]), sparse([[0, 3, 6], [6, 0, 25]])), sparse([[5, 1, 3], [3, 2, 5]]))
    })
  })

  it('should LaTeX gcd', function () {
    const expression = math.parse('gcd(2,3)')
    assert.strictEqual(expression.toTex(), '\\gcd\\left(2,3\\right)')
  })
})