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ruby--ruby/spec/ruby/shared/rational/round.rb
2019-07-27 12:40:09 +02:00

106 lines
4 KiB
Ruby

require_relative '../../spec_helper'
describe :rational_round, shared: true do
before do
@rational = Rational(2200, 7)
end
describe "with no arguments (precision = 0)" do
it "returns an integer" do
@rational.round.should be_kind_of(Integer)
Rational(0, 1).round(0).should be_kind_of(Integer)
Rational(124, 1).round(0).should be_kind_of(Integer)
end
it "returns the truncated value toward the nearest integer" do
@rational.round.should == 314
Rational(0, 1).round(0).should == 0
Rational(2, 1).round(0).should == 2
end
it "returns the rounded value toward the nearest integer" do
Rational(1, 2).round.should == 1
Rational(-1, 2).round.should == -1
Rational(3, 2).round.should == 2
Rational(-3, 2).round.should == -2
Rational(5, 2).round.should == 3
Rational(-5, 2).round.should == -3
end
end
describe "with a precision < 0" do
it "returns an integer" do
@rational.round(-2).should be_kind_of(Integer)
@rational.round(-1).should be_kind_of(Integer)
Rational(0, 1).round(-1).should be_kind_of(Integer)
Rational(2, 1).round(-1).should be_kind_of(Integer)
end
it "moves the truncation point n decimal places left" do
@rational.round(-3).should == 0
@rational.round(-2).should == 300
@rational.round(-1).should == 310
end
end
describe "with a precision > 0" do
it "returns a Rational" do
@rational.round(1).should be_kind_of(Rational)
@rational.round(2).should be_kind_of(Rational)
# Guard against the Mathn library
guard -> { !defined?(Math.rsqrt) } do
Rational(0, 1).round(1).should be_kind_of(Rational)
Rational(2, 1).round(1).should be_kind_of(Rational)
end
end
it "moves the truncation point n decimal places right" do
@rational.round(1).should == Rational(3143, 10)
@rational.round(2).should == Rational(31429, 100)
@rational.round(3).should == Rational(157143, 500)
Rational(0, 1).round(1).should == Rational(0, 1)
Rational(2, 1).round(1).should == Rational(2, 1)
end
it "doesn't alter the value if the precision is too great" do
Rational(3, 2).round(10).should == Rational(3, 2).round(20)
end
# #6605
it "doesn't fail when rounding to an absurdly large positive precision" do
Rational(3, 2).round(2_097_171).should == Rational(3, 2)
end
end
describe "with half option" do
it "returns an Integer when precision is not passed" do
Rational(10, 4).round(half: nil).should == 3
Rational(10, 4).round(half: :up).should == 3
Rational(10, 4).round(half: :down).should == 2
Rational(10, 4).round(half: :even).should == 2
Rational(-10, 4).round(half: nil).should == -3
Rational(-10, 4).round(half: :up).should == -3
Rational(-10, 4).round(half: :down).should == -2
Rational(-10, 4).round(half: :even).should == -2
end
it "returns a Rational when the precision is greater than 0" do
Rational(25, 100).round(1, half: nil).should == Rational(3, 10)
Rational(25, 100).round(1, half: :up).should == Rational(3, 10)
Rational(25, 100).round(1, half: :down).should == Rational(1, 5)
Rational(25, 100).round(1, half: :even).should == Rational(1, 5)
Rational(35, 100).round(1, half: nil).should == Rational(2, 5)
Rational(35, 100).round(1, half: :up).should == Rational(2, 5)
Rational(35, 100).round(1, half: :down).should == Rational(3, 10)
Rational(35, 100).round(1, half: :even).should == Rational(2, 5)
Rational(-25, 100).round(1, half: nil).should == Rational(-3, 10)
Rational(-25, 100).round(1, half: :up).should == Rational(-3, 10)
Rational(-25, 100).round(1, half: :down).should == Rational(-1, 5)
Rational(-25, 100).round(1, half: :even).should == Rational(-1, 5)
end
it "raise for a non-existent round mode" do
-> { Rational(10, 4).round(half: :nonsense) }.should raise_error(ArgumentError, "invalid rounding mode: nonsense")
end
end
end