require "cases/helper"
require "active_model/type"

module ActiveModel
  module Type
    class DecimalTest < ActiveModel::TestCase
      def test_type_cast_decimal
        type = Decimal.new
        assert_equal BigDecimal.new("0"), type.cast(BigDecimal.new("0"))
        assert_equal BigDecimal.new("123"), type.cast(123.0)
        assert_equal BigDecimal.new("1"), type.cast(:"1")
      end

      def test_type_cast_decimal_from_invalid_string
        type = Decimal.new
        assert_nil type.cast("")
        assert_equal BigDecimal.new("1"), type.cast("1ignore")
        assert_equal BigDecimal.new("0"), type.cast("bad1")
        assert_equal BigDecimal.new("0"), type.cast("bad")
      end

      def test_type_cast_decimal_from_float_with_large_precision
        type = Decimal.new(precision: ::Float::DIG + 2)
        assert_equal BigDecimal.new("123.0"), type.cast(123.0)
      end

      def test_type_cast_from_float_with_unspecified_precision
        type = Decimal.new
        assert_equal 22.68.to_d, type.cast(22.68)
      end

      def test_type_cast_decimal_from_rational_with_precision
        type = Decimal.new(precision: 2)
        assert_equal BigDecimal("0.33"), type.cast(Rational(1, 3))
      end

      def test_type_cast_decimal_from_rational_with_precision_and_scale
        type = Decimal.new(precision: 4, scale: 2)
        assert_equal BigDecimal("0.33"), type.cast(Rational(1, 3))
      end

      def test_type_cast_decimal_from_rational_without_precision_defaults_to_18_36
        type = Decimal.new
        assert_equal BigDecimal("0.333333333333333333E0"), type.cast(Rational(1, 3))
      end

      def test_type_cast_decimal_from_object_responding_to_d
        value = Object.new
        def value.to_d
          BigDecimal.new("1")
        end
        type = Decimal.new
        assert_equal BigDecimal("1"), type.cast(value)
      end

      def test_changed?
        type = Decimal.new

        assert type.changed?(5.0, 5.0, '5.0wibble')
        assert_not type.changed?(5.0, 5.0, '5.0')
        assert_not type.changed?(-5.0, -5.0, '-5.0')
      end

      def test_scale_is_applied_before_precision_to_prevent_rounding_errors
        type = Decimal.new(precision: 5, scale: 3)

        assert_equal BigDecimal("1.250"), type.cast(1.250473853637869)
        assert_equal BigDecimal("1.250"), type.cast("1.250473853637869")
      end
    end
  end
end
