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path: root/spec/ruby/library/bigdecimal/floor_spec.rb
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require_relative '../../spec_helper'

ruby_version_is ""..."3.4" do
  require 'bigdecimal'

  describe "BigDecimal#floor" do
    before :each do
      @one = BigDecimal("1")
      @three = BigDecimal("3")
      @four = BigDecimal("4")
      @zero = BigDecimal("0")
      @mixed = BigDecimal("1.23456789")
      @mixed_big = BigDecimal("1.23456789E100")
      @pos_int = BigDecimal("2E5555")
      @neg_int = BigDecimal("-2E5555")
      @pos_frac = BigDecimal("2E-9999")
      @neg_frac = BigDecimal("-2E-9999")

      @infinity = BigDecimal("Infinity")
      @infinity_neg = BigDecimal("-Infinity")
      @nan = BigDecimal("NaN")
      @zero_pos = BigDecimal("+0")
      @zero_neg = BigDecimal("-0")
    end

    it "returns the greatest integer smaller or equal to self" do
      @pos_int.floor.should == @pos_int
      @neg_int.floor.should == @neg_int
      @pos_frac.floor.should == @zero
      @neg_frac.floor.should == BigDecimal("-1")
      @zero.floor.should == 0
      @zero_pos.floor.should == @zero_pos
      @zero_neg.floor.should == @zero_neg

      BigDecimal('2.3').floor.should == 2
      BigDecimal('2.5').floor.should == 2
      BigDecimal('2.9999').floor.should == 2
      BigDecimal('-2.3').floor.should == -3
      BigDecimal('-2.5').floor.should == -3
      BigDecimal('-2.9999').floor.should == -3
      BigDecimal('0.8').floor.should == 0
      BigDecimal('-0.8').floor.should == -1
    end

    it "raise exception, if self is special value" do
      -> { @infinity.floor }.should raise_error(FloatDomainError)
      -> { @infinity_neg.floor }.should raise_error(FloatDomainError)
      -> { @nan.floor }.should raise_error(FloatDomainError)
    end

    it "returns n digits right of the decimal point if given n > 0" do
      @mixed.floor(1).should == BigDecimal("1.2")
      @mixed.floor(5).should == BigDecimal("1.23456")

      BigDecimal("-0.03").floor(1).should == BigDecimal("-0.1")
      BigDecimal("0.03").floor(1).should == BigDecimal("0")

      BigDecimal("23.45").floor(0).should == BigDecimal('23')
      BigDecimal("23.45").floor(1).should == BigDecimal('23.4')
      BigDecimal("23.45").floor(2).should == BigDecimal('23.45')

      BigDecimal("-23.45").floor(0).should == BigDecimal('-24')
      BigDecimal("-23.45").floor(1).should == BigDecimal('-23.5')
      BigDecimal("-23.45").floor(2).should == BigDecimal('-23.45')

      BigDecimal("2E-10").floor(0).should == @zero
      BigDecimal("2E-10").floor(9).should == @zero
      BigDecimal("2E-10").floor(10).should == BigDecimal('2E-10')
      BigDecimal("2E-10").floor(11).should == BigDecimal('2E-10')

      (1..10).each do |n|
        # 0.3, 0.33, 0.333, etc.
        (@one.div(@three,20)).floor(n).should == BigDecimal("0.#{'3'*n}")
        # 1.3, 1.33, 1.333, etc.
        (@four.div(@three,20)).floor(n).should == BigDecimal("1.#{'3'*n}")
        (BigDecimal('31').div(@three,20)).floor(n).should == BigDecimal("10.#{'3'*n}")
      end
      (1..10).each do |n|
        # -0.4, -0.34, -0.334, etc.
        ([email protected](@three,20)).floor(n).should == BigDecimal("-0.#{'3'*(n-1)}4")
      end
      (1..10).each do |n|
        (@three.div(@one,20)).floor(n).should == @three
      end
      (1..10).each do |n|
        ([email protected](@one,20)).floor(n).should == -@three
      end
    end

    it "sets n digits left of the decimal point to 0, if given n < 0" do
      BigDecimal("13345.234").floor(-2).should == BigDecimal("13300.0")
      @mixed_big.floor(-99).should == BigDecimal("0.12E101")
      @mixed_big.floor(-100).should == BigDecimal("0.1E101")
      @mixed_big.floor(-95).should == BigDecimal("0.123456E101")
      (1..10).each do |n|
        BigDecimal('1.8').floor(-n).should == @zero
      end
      BigDecimal("1E10").floor(-30).should == @zero
      BigDecimal("-1E10").floor(-30).should == BigDecimal('-1E30')
    end

  end
end