text: const assert = require('assert')
  const math = require('../../src/main')
  const string = math.string
  
  describe('string', function () {
    it('should be \'\' if called with no argument', function () {
      assert.equal(string(), '')
    })
  
    it('should convert a boolean to a string', function () {
      assert.equal(string(true), 'true')
      assert.equal(string(false), 'false')
    })
  
    it('should convert null to a string', function () {
      assert.equal(string(null), 'null')
    })
  
    it('should be the identity if called with a string', function () {
      assert.equal(string('hello'), 'hello')
      assert.equal(string(''), '')
      assert.equal(string(' '), ' ')
    })
  
    it('should convert the elements of an array to strings', function () {
      assert.deepEqual(string([[2, true], ['hi', null]]), [['2', 'true'], ['hi', 'null']])
    })
  
    it('should convert the elements of a matrix to strings', function () {
      assert.deepEqual(string(math.matrix([[2, true], ['hi', null]])),
        math.matrix([['2', 'true'], ['hi', 'null']]))
    })
  
    it('should convert a number to string', function () {
      assert.equal(string(1 / 8), '0.125')
      assert.equal(string(2.1e-3), '0.0021')
      assert.equal(string(123456789), '1.23456789e+8')
      assert.equal(string(2000000), '2e+6')
    })
  
    it('should convert a bignumber to string', function () {
      assert.equal(string(math.bignumber('2.3e+500')), '2.3e+500')
    })
  
    it('should convert a complex number to string', function () {
      assert.equal(string(math.complex(2, 3)), '2 + 3i')
    })
  
    it('should convert a unit to string', function () {
      assert.equal(string(math.unit('5cm')), '5 cm')
    })
  
    it('should throw an error if called with wrong number of arguments', function () {
      assert.throws(function () { string(1, 2) }, /TypeError: Too many arguments/)
      assert.throws(function () { string(1, 2, 3) }, /TypeError: Too many arguments/)
    })
  })
  