import assert from 'assert'
import math from '../../../../src/defaultInstance.js'

describe('im', function () {
  it('should return the imaginary part of a complex number', function () {
    assert.strictEqual(math.im(math.complex(2, 3)), 3)
    assert.strictEqual(math.im(math.complex(-2, -3)), -3)
    assert.strictEqual(math.im(math.i), 1)
  })

  it('should return the imaginary part of a real number', function () {
    assert.strictEqual(math.im(2), 0)
  })

  it('should return the imaginary part of a big number', function () {
    assert.deepStrictEqual(math.im(math.bignumber(2)), math.bignumber(0))
  })

  it('should return the imaginary part of a boolean', function () {
    assert.strictEqual(math.im(true), 0)
    assert.strictEqual(math.im(false), 0)
  })

  it('should return the imaginary part of a boolean', function () {
    assert.strictEqual(math.im(true), 0)
    assert.strictEqual(math.im(false), 0)
  })

  it('should return the imaginary part for each element in a matrix', function () {
    assert.deepStrictEqual(math.im([2, math.complex('3-6i')]), [0, -6])
    assert.deepStrictEqual(math.im(math.matrix([2, math.complex('3-6i')])).valueOf(), [0, -6])
  })

  it('should throw an error when called with an unsupported type of argument', function () {
    assert.throws(function () { math.im(new Date()) }, /TypeError: Unexpected type of argument/)
    assert.throws(function () { math.im(math.unit('5cm')) }, /TypeError: Unexpected type of argument/)
  })

  it('should throw an error in case of invalid number of arguments', function () {
    assert.throws(function () { math.im() }, /TypeError: Too few arguments/)
    assert.throws(function () { math.im(1, 2) }, /TypeError: Too many arguments/)
  })

  it('should LaTeX im', function () {
    const expression = math.parse('im(1+i)')
    assert.strictEqual(expression.toTex(), '\\Im\\left\\lbrace1+ i\\right\\rbrace')
  })
})