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ruby--ruby/spec/ruby/core/float/round_spec.rb
2022-06-26 14:50:14 +02:00

194 lines
8.2 KiB
Ruby

require_relative '../../spec_helper'
describe "Float#round" do
it "returns the nearest Integer" do
5.5.round.should == 6
0.4.round.should == 0
0.6.round.should == 1
-1.4.round.should == -1
-2.8.round.should == -3
0.0.round.should == 0
end
it "returns the nearest Integer for Float near the limit" do
0.49999999999999994.round.should == 0
-0.49999999999999994.round.should == 0
end
it "raises FloatDomainError for exceptional values" do
-> { (+infinity_value).round }.should raise_error(FloatDomainError)
-> { (-infinity_value).round }.should raise_error(FloatDomainError)
-> { nan_value.round }.should raise_error(FloatDomainError)
end
it "rounds self to an optionally given precision" do
5.5.round(0).should eql(6)
5.7.round(1).should eql(5.7)
1.2345678.round(2).should == 1.23
123456.78.round(-2).should eql(123500) # rounded up
-123456.78.round(-2).should eql(-123500)
12.345678.round(3.999).should == 12.346
end
it "returns zero when passed a negative argument with magnitude greater than magnitude of the whole number portion of the Float" do
0.8346268.round(-1).should eql(0)
end
it "raises a TypeError when its argument can not be converted to an Integer" do
-> { 1.0.round("4") }.should raise_error(TypeError)
-> { 1.0.round(nil) }.should raise_error(TypeError)
end
it "raises FloatDomainError for exceptional values when passed a non-positive precision" do
-> { Float::INFINITY.round( 0) }.should raise_error(FloatDomainError)
-> { Float::INFINITY.round(-2) }.should raise_error(FloatDomainError)
-> { (-Float::INFINITY).round( 0) }.should raise_error(FloatDomainError)
-> { (-Float::INFINITY).round(-2) }.should raise_error(FloatDomainError)
end
it "raises RangeError for NAN when passed a non-positive precision" do
-> { Float::NAN.round(0) }.should raise_error(RangeError)
-> { Float::NAN.round(-2) }.should raise_error(RangeError)
end
it "returns self for exceptional values when passed a non-negative precision" do
Float::INFINITY.round(2).should == Float::INFINITY
(-Float::INFINITY).round(2).should == -Float::INFINITY
Float::NAN.round(2).should be_nan
end
# redmine:5227
it "works for corner cases" do
42.0.round(308).should eql(42.0)
1.0e307.round(2).should eql(1.0e307)
end
# redmine:5271
it "returns rounded values for big argument" do
0.42.round(2.0**30).should == 0.42
end
it "returns big values rounded to nearest" do
+2.5e20.round(-20).should eql( +3 * 10 ** 20 )
-2.5e20.round(-20).should eql( -3 * 10 ** 20 )
end
# redmine #5272
it "returns rounded values for big values" do
+2.4e20.round(-20).should eql( +2 * 10 ** 20 )
-2.4e20.round(-20).should eql( -2 * 10 ** 20 )
+2.5e200.round(-200).should eql( +3 * 10 ** 200 )
+2.4e200.round(-200).should eql( +2 * 10 ** 200 )
-2.5e200.round(-200).should eql( -3 * 10 ** 200 )
-2.4e200.round(-200).should eql( -2 * 10 ** 200 )
end
it "returns different rounded values depending on the half option" do
2.5.round(half: nil).should eql(3)
2.5.round(half: :up).should eql(3)
2.5.round(half: :down).should eql(2)
2.5.round(half: :even).should eql(2)
3.5.round(half: nil).should eql(4)
3.5.round(half: :up).should eql(4)
3.5.round(half: :down).should eql(3)
3.5.round(half: :even).should eql(4)
(-2.5).round(half: nil).should eql(-3)
(-2.5).round(half: :up).should eql(-3)
(-2.5).round(half: :down).should eql(-2)
(-2.5).round(half: :even).should eql(-2)
end
it "rounds self to an optionally given precision with a half option" do
5.55.round(1, half: nil).should eql(5.6)
5.55.round(1, half: :up).should eql(5.6)
5.55.round(1, half: :down).should eql(5.5)
5.55.round(1, half: :even).should eql(5.6)
-5.55.round(1, half: nil).should eql(-5.6)
-5.55.round(1, half: :up).should eql(-5.6)
-5.55.round(1, half: :down).should eql(-5.5)
-5.55.round(1, half: :even).should eql(-5.6)
end
it "preserves cases where neighbouring floating pointer number increase the decimal places" do
4.8100000000000005.round(5, half: nil).should eql(4.81)
4.8100000000000005.round(5, half: :up).should eql(4.81)
4.8100000000000005.round(5, half: :down).should eql(4.81)
4.8100000000000005.round(5, half: :even).should eql(4.81)
-4.8100000000000005.round(5, half: nil).should eql(-4.81)
-4.8100000000000005.round(5, half: :up).should eql(-4.81)
-4.8100000000000005.round(5, half: :down).should eql(-4.81)
-4.8100000000000005.round(5, half: :even).should eql(-4.81)
4.81.round(5, half: nil).should eql(4.81)
4.81.round(5, half: :up).should eql(4.81)
4.81.round(5, half: :down).should eql(4.81)
4.81.round(5, half: :even).should eql(4.81)
-4.81.round(5, half: nil).should eql(-4.81)
-4.81.round(5, half: :up).should eql(-4.81)
-4.81.round(5, half: :down).should eql(-4.81)
-4.81.round(5, half: :even).should eql(-4.81)
4.809999999999999.round(5, half: nil).should eql(4.81)
4.809999999999999.round(5, half: :up).should eql(4.81)
4.809999999999999.round(5, half: :down).should eql(4.81)
4.809999999999999.round(5, half: :even).should eql(4.81)
-4.809999999999999.round(5, half: nil).should eql(-4.81)
-4.809999999999999.round(5, half: :up).should eql(-4.81)
-4.809999999999999.round(5, half: :down).should eql(-4.81)
-4.809999999999999.round(5, half: :even).should eql(-4.81)
end
ruby_bug "", ""..."3.3" do
# These numbers are neighbouring floating point numbers round a
# precise value. They test that the rounding modes work correctly
# round that value and precision is not lost which might cause
# incorrect results.
it "does not lose precision during the rounding process" do
767573.1875850001.round(5, half: nil).should eql(767573.18759)
767573.1875850001.round(5, half: :up).should eql(767573.18759)
767573.1875850001.round(5, half: :down).should eql(767573.18759)
767573.1875850001.round(5, half: :even).should eql(767573.18759)
-767573.1875850001.round(5, half: nil).should eql(-767573.18759)
-767573.1875850001.round(5, half: :up).should eql(-767573.18759)
-767573.1875850001.round(5, half: :down).should eql(-767573.18759)
-767573.1875850001.round(5, half: :even).should eql(-767573.18759)
767573.187585.round(5, half: nil).should eql(767573.18759)
767573.187585.round(5, half: :up).should eql(767573.18759)
767573.187585.round(5, half: :down).should eql(767573.18758)
767573.187585.round(5, half: :even).should eql(767573.18758)
-767573.187585.round(5, half: nil).should eql(-767573.18759)
-767573.187585.round(5, half: :up).should eql(-767573.18759)
-767573.187585.round(5, half: :down).should eql(-767573.18758)
-767573.187585.round(5, half: :even).should eql(-767573.18758)
767573.1875849998.round(5, half: nil).should eql(767573.18758)
767573.1875849998.round(5, half: :up).should eql(767573.18758)
767573.1875849998.round(5, half: :down).should eql(767573.18758)
767573.1875849998.round(5, half: :even).should eql(767573.18758)
-767573.1875849998.round(5, half: nil).should eql(-767573.18758)
-767573.1875849998.round(5, half: :up).should eql(-767573.18758)
-767573.1875849998.round(5, half: :down).should eql(-767573.18758)
-767573.1875849998.round(5, half: :even).should eql(-767573.18758)
end
end
it "raises FloatDomainError for exceptional values with a half option" do
-> { (+infinity_value).round(half: :up) }.should raise_error(FloatDomainError)
-> { (-infinity_value).round(half: :down) }.should raise_error(FloatDomainError)
-> { nan_value.round(half: :even) }.should raise_error(FloatDomainError)
end
it "raise for a non-existent round mode" do
-> { 14.2.round(half: :nonsense) }.should raise_error(ArgumentError, "invalid rounding mode: nonsense")
end
describe "when 0.0 is given" do
it "returns self for positive ndigits" do
(0.0).round(5).inspect.should == "0.0"
(-0.0).round(1).inspect.should == "-0.0"
end
it "returns 0 for 0 or undefined ndigits" do
(0.0).round.should == 0
(-0.0).round(0).should == 0
(0.0).round(half: :up) == 0
end
end
end