1require_relative "testbase"
2
3require 'bigdecimal/util'
4
5class TestBigDecimalUtil < Test::Unit::TestCase
6  def test_BigDecimal_to_d
7    x = BigDecimal(1)
8    assert_same(x, x.to_d)
9  end
10
11  def test_Integer_to_d
12    assert_equal(BigDecimal(1), 1.to_d)
13    assert_equal(BigDecimal(2<<100), (2<<100).to_d)
14  end
15
16  def test_Float_to_d_without_precision
17    delta = 1.0/10**(Float::DIG + 1)
18    assert_in_delta(BigDecimal(0.5, Float::DIG+1), 0.5.to_d, delta)
19    assert_in_delta(BigDecimal(355.0/113.0, Float::DIG+1), (355.0/113.0).to_d, delta)
20  end
21
22  def test_Float_to_d_with_precision
23    digits = 5
24    delta = 1.0/10**(digits)
25    assert_in_delta(BigDecimal(0.5, 5), 0.5.to_d(digits), delta)
26    assert_in_delta(BigDecimal(355.0/113.0, 5), (355.0/113.0).to_d(digits), delta)
27  end
28
29  def test_Rational_to_d
30    digits = 100
31    delta = 1.0/10**(digits)
32    assert_in_delta(BigDecimal(1.quo(2), digits), 1.quo(2).to_d(digits), delta)
33    assert_in_delta(BigDecimal(355.quo(113), digits), 355.quo(113).to_d(digits), delta)
34  end
35
36  def test_Rational_to_d_with_zero_precision
37    assert_raise(ArgumentError) { 355.quo(113).to_d(0) }
38  end
39
40  def test_Rational_to_d_with_negative_precision
41    assert_raise(ArgumentError) { 355.quo(113).to_d(-42) }
42  end
43end
44