mathjs/test/function/utils/isInteger.test.js

Math.js is an extensive math library for JavaScript and Node.js. It features a flexible expression parser with support for symbolic computation, comes with a large set of built-in functions and constants, and offers an integrated solution to work with dif

var assert = require('assert');
var math = require('../../../index');
var isInteger = math.isInteger;
var bignumber = math.bignumber;
var fraction = math.fraction;

describe('isInteger', function() {

  it('should test whether a number is an integer', function() {
    assert.strictEqual(isInteger(2), true);
    assert.strictEqual(isInteger(0), true);
    assert.strictEqual(isInteger(-3), true);
    assert.strictEqual(isInteger(-0.5), false);
    assert.strictEqual(isInteger(0.5), false);
    assert.strictEqual(isInteger(Infinity), false);
    assert.strictEqual(isInteger(-Infinity), false);
    assert.strictEqual(isInteger(NaN), false);
    assert.strictEqual(isInteger(0.1 + 0.2), false); // TODO: what to do with round off errors?
  });

  it('should test whether a boolean is an integer', function() {
    assert.strictEqual(isInteger(true), true);
    assert.strictEqual(isInteger(false), true);
  });

  it('should test whether a BigNumber is an integer', function() {
    assert.strictEqual(isInteger(bignumber(2)), true);
    assert.strictEqual(isInteger(bignumber(0)), true);
    assert.strictEqual(isInteger(bignumber(-3)), true);
    assert.strictEqual(isInteger(bignumber(-0.5)), false);
    assert.strictEqual(isInteger(bignumber(0.5)), false);
    assert.strictEqual(isInteger(bignumber(Infinity)), false);
    assert.strictEqual(isInteger(bignumber(-Infinity)), false);
    assert.strictEqual(isInteger(bignumber(NaN)), false);
  });

  it('should test whether a Fraction is an integer', function() {
    assert.strictEqual(isInteger(fraction(2)), true);
    assert.strictEqual(isInteger(fraction(0)), true);
    assert.strictEqual(isInteger(fraction(-3)), true);
    assert.strictEqual(isInteger(fraction(-0.5)), false);
    assert.strictEqual(isInteger(fraction(0.5)), false);
  });

  it('should test whether a string contains an integer', function() {
    assert.strictEqual(isInteger('2'), true);
    assert.strictEqual(isInteger('0'), true);
    assert.strictEqual(isInteger('-3'), true);
    assert.strictEqual(isInteger('-0.5'), false);
    assert.strictEqual(isInteger('0.5'), false);
  });

  it('should test isInteger element wise on an Array', function() {
    assert.deepEqual(isInteger([2, 5, 0.5, 3]), [true, true, false, true]);
  });

  it('should test isInteger element wise on a Matrix', function() {
    assert.deepEqual(isInteger(math.matrix([2, 5, 0.5, 3])), math.matrix([true, true, false, true]));
  });

  it('should throw an error in case of unsupported data types', function() {
    assert.throws(function () {isInteger(math.complex(2, 3))}, /TypeError: Unexpected type of argument/);
    assert.throws(function () {isInteger(math.unit('5 cm'))}, /TypeError: Unexpected type of argument/);
    assert.throws(function () {isInteger(new Date())}, /TypeError: Unexpected type of argument/);
    assert.throws(function () {isInteger({})}, /TypeError: Unexpected type of argument/);
  });

});