mathjs/test/function/relational/unequal.test.js

Math.js is an extensive math library for JavaScript and Node.js. It features a flexible expression parser and offers an integrated solution to work with numbers, big numbers, complex numbers, units, and matrices.

// test unequal
var assert = require('assert'),
    error = require('../../../lib/error/index'),
    math = require('../../../index'),
    bignumber = math.bignumber,
    complex = math.complex,
    matrix = math.matrix,
    unit = math.unit,
    unequal = math.unequal;

describe('unequal', function() {

  it('should compare two numbers correctly', function() {
    assert.equal(unequal(2, 3), true);
    assert.equal(unequal(2, 2), false);
    assert.equal(unequal(0, 0), false);
    assert.equal(unequal(-2, 2), true);
    assert.equal(unequal(true, 1), false);
  });

  it('should compare two floating point numbers correctly', function() {
    // NaN
    assert.equal(unequal(Number.NaN, Number.NaN), true);
    // Infinity
    assert.equal(unequal(Number.POSITIVE_INFINITY, Number.POSITIVE_INFINITY), false);
    assert.equal(unequal(Number.NEGATIVE_INFINITY, Number.NEGATIVE_INFINITY), false);
    assert.equal(unequal(Number.POSITIVE_INFINITY, Number.NEGATIVE_INFINITY), true);
    assert.equal(unequal(Number.NEGATIVE_INFINITY, Number.POSITIVE_INFINITY), true);
    assert.equal(unequal(Number.POSITIVE_INFINITY, 2.0), true);
    assert.equal(unequal(2.0, Number.POSITIVE_INFINITY), true);
    assert.equal(unequal(Number.NEGATIVE_INFINITY, 2.0), true);
    assert.equal(unequal(2.0, Number.NEGATIVE_INFINITY), true);
    assert.equal(unequal(Number.NaN, Number.POSITIVE_INFINITY), true);
    assert.equal(unequal(Number.POSITIVE_INFINITY, Number.NaN), true);
    assert.equal(unequal(Number.NaN, Number.NEGATIVE_INFINITY), true);
    assert.equal(unequal(Number.NEGATIVE_INFINITY, Number.NaN), true);
    // floating point numbers
    assert.equal(unequal(0.3 - 0.2, 0.1), false);
  });

  it('should compare two booleans', function() {
    assert.equal(unequal(true, true), false);
    assert.equal(unequal(true, false), true);
    assert.equal(unequal(false, true), true);
    assert.equal(unequal(false, false), false);
  });

  it('should compare mixed numbers and booleans', function() {
    assert.equal(unequal(2, true), true);
    assert.equal(unequal(1, true), false);
    assert.equal(unequal(0, true), true);
    assert.equal(unequal(true, 2), true);
    assert.equal(unequal(true, 1), false);
    assert.equal(unequal(false, 2), true);
    assert.equal(unequal(false, 0), false);
  });

  it('should compare bignumbers', function() {
    assert.deepEqual(unequal(bignumber(2), bignumber(3)), true);
    assert.deepEqual(unequal(bignumber(2), bignumber(2)), false);
    assert.deepEqual(unequal(bignumber(3), bignumber(2)), true);
    assert.deepEqual(unequal(bignumber(0), bignumber(0)), false);
    assert.deepEqual(unequal(bignumber(-2), bignumber(2)), true);
  });

  it('should compare mixed numbers and bignumbers', function() {
    assert.deepEqual(unequal(bignumber(2), 3), true);
    assert.deepEqual(unequal(2, bignumber(2)), false);

    assert.equal(unequal(1/3, bignumber(1).div(3)), false);
    assert.equal(unequal(bignumber(1).div(3), 1/3), false);
  });

  it('should compare mixed booleans and bignumbers', function() {
    assert.deepEqual(unequal(bignumber(0.1), true), true);
    assert.deepEqual(unequal(bignumber(1), true), false);
    assert.deepEqual(unequal(bignumber(1), false), true);
    assert.deepEqual(unequal(bignumber(0), false), false);
    assert.deepEqual(unequal(false, bignumber(0)), false);
    assert.deepEqual(unequal(true, bignumber(0)), true);
    assert.deepEqual(unequal(true, bignumber(1)), false);
  });

  it('should compare two complex numbers correctly', function() {
    assert.equal(unequal(complex(2,3), complex(2,4)), true);
    assert.equal(unequal(complex(2,3), complex(2,3)), false);
    assert.equal(unequal(complex(1,3), complex(2,3)), true);
    assert.equal(unequal(complex(1,3), complex(2,4)), true);
    assert.equal(unequal(complex(2,0), 2), false);
    assert.equal(unequal(complex(2,1), 2), true);
    assert.equal(unequal(2, complex(2, 0)), false);
    assert.equal(unequal(2, complex(2, 1)), true);
    assert.equal(unequal(complex(2,0), 3), true);
  });

  it('should compare mixed complex numbers and bignumbers (downgrades to numbers)', function() {
    assert.deepEqual(unequal(math.complex(6, 0), bignumber(6)), false);
    assert.deepEqual(unequal(math.complex(6, -2), bignumber(6)), true);
    assert.deepEqual(unequal(bignumber(6), math.complex(6, 0)), false);
    assert.deepEqual(unequal(bignumber(6), math.complex(6, 4)), true);
  });

  it('should compare two quantitites of the same unit correctly', function() {
    assert.equal(unequal(unit('100cm'), unit('10inch')), true);
    assert.equal(unequal(unit('100cm'), unit('1m')), false);
    //assert.equal(unequal(unit('12inch'), unit('1foot')), false); // round-off error :(
    //assert.equal(unequal(unit('2.54cm'), unit('1inch')), false); // round-off error :(
  });

  it('should compare null', function() {
    assert.equal(unequal(null, null), false);
    assert.equal(unequal(null, undefined), true);
    assert.equal(unequal(0, null), true);
    assert.equal(unequal('null', null), true);
  });

  it('should compare undefined', function() {
    assert.equal(unequal(undefined, undefined), false);
    assert.equal(unequal(undefined, 'undefined'), true);
    assert.equal(unequal(undefined, null), true);
    assert.equal(unequal(2, undefined), true);
  });

  it('should apply configuration option epsilon', function() {
    var mymath = math.create();
    assert.equal(mymath.unequal(1, 0.991), true);
    mymath.config({epsilon: 1e-2});
    assert.equal(mymath.unequal(1, 0.991), false);
  });

  it('should throw an error when comparing numbers and units', function() {
    assert.throws(function () {unequal(unit('100cm'), 22)});
    assert.throws(function () {unequal(22, unit('100cm'))});
  });

  it('should throw an error when comparing bignumbers and units', function() {
    assert.throws(function () {unequal(unit('100cm'), bignumber(22))});
    assert.throws(function () {unequal(bignumber(22), unit('100cm'))});
  });

  it('should throw an error for two measures of different units', function() {
    assert.throws(function () {unequal(math.unit(5, 'km'), math.unit(100, 'gram'));});
  });

  it('should compare two strings correctly', function() {
    assert.equal(unequal('0', 0), false);
    assert.equal(unequal('Hello', 'hello'), true);
    assert.equal(unequal('hello', 'hello'), false);
  });

  it('should compare a string an matrix elementwise', function() {
    assert.deepEqual(unequal('B', ['A', 'B', 'C']), [true, false, true]);
    assert.deepEqual(unequal(['A', 'B', 'C'], 'B'), [true, false, true]);
  });

  it('should compare two matrices element wise', function() {
    assert.deepEqual(unequal([1,4,5], [3,4,5]), [true, false, false]);
    assert.deepEqual(unequal([1,4,5], matrix([3,4,5])), matrix([true, false, false]));
  });

  it('should throw an error if matrices have different sizes', function() {
    assert.throws(function () {unequal([1,4,5], [3,4])});
  });

  it('should throw an error in case of invalid number of arguments', function() {
    assert.throws(function () {unequal(1)}, error.ArgumentsError);
    assert.throws(function () {unequal(1, 2, 3)}, error.ArgumentsError);
  });

});