mathjs/test/constants.test.js

const assert = require('assert')
const core = require('../src/core/core')
const math = require('../src/main')
const approx = require('../tools/approx')
const constants = require('../src/constants')

describe('constants', function () {
  const bigmath = math.create({ number: 'BigNumber', precision: 64 })
  const realmath = core.create()
  realmath.import(constants)

  describe('number', function () {
    [math, realmath].forEach(function (instance) {
      it('should have pi', function () {
        approx.equal(instance.pi, 3.14159265358979323846264338327950288419716939937510582097494459230781640628620899862803482534211706798214808651328230664)
        approx.equal(instance.PI, instance.pi)
      })

      it('should have tau', function () {
        approx.equal(instance.tau, 6.28318530717959)
      })

      it('should have phi, golden ratio', function () {
        approx.equal(instance.phi, 1.61803398874989484820458683436563811772030917980576286213545)
      })

      it('should have e (euler constant)', function () {
        approx.equal(instance.e, 2.71828182845905)
      })

      it('should have LN2', function () {
        approx.equal(instance.LN2, 0.69314718055994530941723212145817656807550013436025525412068000949339362196969471560586332699641868754200148102057068573)
      })

      it('should have LN10', function () {
        approx.equal(instance.LN10, 2.30258509299404568401799145468436420760110148862877297603332790096757260967735248023599720508959829834196778404228624863)
      })

      it('should have LOG2E', function () {
        approx.equal(instance.LOG2E, 1.44269504088896340735992468100189213742664595415298593413544940693110921918118507988552662289350634449699751830965254425)
      })

      it('should have LOG10E', function () {
        approx.equal(instance.LOG10E, 0.43429448190325182765112891891660508229439700580366656611445378316586464920887077472922494933843174831870610674476630373)
      })

      it('should have PI', function () {
        approx.equal(instance.PI, 3.14159265358979)
      })

      it('should have SQRT1_2', function () {
        approx.equal(instance.SQRT1_2, 0.70710678118654752440084436210484903928483593768847403658833986899536623923105351942519376716382078636750692311545614851)
      })

      it('should have SQRT2', function () {
        approx.equal(instance.SQRT2, 1.41421356237309504880168872420969807856967187537694807317667973799073247846210703885038753432764157273501384623091229702)
      })

      it('should have Infinity', function () {
        assert.strictEqual(instance.Infinity, Infinity)
      })

      it('should have NaN', function () {
        assert.ok(isNaN(instance.NaN))
      })
    })
  })

  describe('bignumbers', function () {
    it('should have bignumber pi', function () {
      assert.strictEqual(bigmath.pi.toString(), '3.141592653589793238462643383279502884197169399375105820974944592')
    })

    it('should have bignumber tau', function () {
      assert.strictEqual(bigmath.tau.toString(), '6.283185307179586476925286766559005768394338798750211641949889184')
    })

    it('should have bignumber phi, golden ratio', function () {
      assert.strictEqual(bigmath.phi.toString(), '1.618033988749894848204586834365638117720309179805762862135448623')
    })

    it('should have bignumber e', function () {
      assert.strictEqual(bigmath.e.toString(), '2.718281828459045235360287471352662497757247093699959574966967628')
    })

    it('should have bignumber LN2', function () {
      assert.strictEqual(bigmath.LN2.toString(), '0.6931471805599453094172321214581765680755001343602552541206800095')
    })

    it('should have bignumber LN10', function () {
      assert.strictEqual(bigmath.LN10.toString(), '2.302585092994045684017991454684364207601101488628772976033327901')
    })

    it('should have bignumber LOG2E', function () {
      assert.strictEqual(bigmath.LOG2E.toString(), '1.442695040888963407359924681001892137426645954152985934135449407')
    })

    it('should have bignumber LOG10E', function () {
      assert.strictEqual(bigmath.LOG10E.toString(), '0.4342944819032518276511289189166050822943970058036665661144537832')
    })

    it('should have bignumber PI (upper case)', function () {
      assert.strictEqual(bigmath.PI.toString(), '3.141592653589793238462643383279502884197169399375105820974944592')
    })

    it('should have bignumber SQRT1_2', function () {
      assert.strictEqual(bigmath.SQRT1_2.toString(), '0.707106781186547524400844362104849039284835937688474036588339869')
    })

    it('should have bignumber SQRT2', function () {
      assert.strictEqual(bigmath.SQRT2.toString(), '1.414213562373095048801688724209698078569671875376948073176679738')
    })

    it('should have bignumber Infinity', function () {
      assert(bigmath.Infinity instanceof bigmath.type.BigNumber)
      assert.strictEqual(bigmath.Infinity.toString(), 'Infinity')
    })

    it('should have bignumber NaN', function () {
      assert(bigmath.NaN instanceof bigmath.type.BigNumber)
      assert.strictEqual(bigmath.NaN.toString(), 'NaN')
      assert.ok(isNaN(bigmath.NaN))
    })
  })

  describe('complex', function () {
    [math, bigmath].forEach(function (math) {
      it('should have i', function () {
        assert.strictEqual(math.i.re, 0)
        assert.strictEqual(math.i.im, 1)
        assert.deepStrictEqual(math.i, math.complex(0, 1))
      })
    })
  })

  describe('real', function () {
    it('does not have i', function () {
      assert.strictEqual(realmath.i, undefined)
    })
  })

  describe('universal behavior', function () {
    [math, bigmath, realmath].forEach(function (instance) {
      it('should have true and false', function () {
        assert.strictEqual(instance.true, true)
        assert.strictEqual(instance.false, false)
      })

      it('should have null', function () {
        assert.strictEqual(instance['null'], null)
      })

      it('should return message when uninitialized', function () {
        assert.strictEqual(instance.uninitialized, 'Error: Constant uninitialized is removed since v4.0.0. Use null instead')
      })
    })
  })

  describe('evaluation with constants', function () {
    // Do these tests really belong in constants.test.js ?
    approx.equal(math.sin(math.pi / 2), 1)

    assert.deepStrictEqual(math.round(math.add(1, math.pow(math.e, math.multiply(math.pi, math.i))), 5), math.complex(0))
    assert.deepStrictEqual(math.round(math.eval('1+e^(pi*i)'), 5), math.complex(0))

    assert.deepStrictEqual(math.sqrt(-1), math.i)
    assert.deepStrictEqual(math.eval('i'), math.complex(0, 1))

    assert.strictEqual(math.eval('true'), true)
    assert.strictEqual(math.eval('false'), false)
  })
})