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require_relative '../../spec_helper'
describe :rational_truncate, shared: true do
before do
@rational = Rational(2200, 7)
end
describe "with no arguments (precision = 0)" do
it "returns an integer" do
@rational.truncate.should be_kind_of(Integer)
end
it "returns the truncated value toward 0" do
@rational.truncate.should == 314
Rational(1, 2).truncate.should == 0
Rational(-1, 2).truncate.should == 0
end
end
describe "with an explicit precision = 0" do
it "returns an integer" do
@rational.truncate(0).should be_kind_of(Integer)
end
it "returns the truncated value toward 0" do
@rational.truncate(0).should == 314
Rational(1, 2).truncate(0).should == 0
Rational(-1, 2).truncate(0).should == 0
end
end
describe "with a precision < 0" do
it "returns an integer" do
@rational.truncate(-2).should be_kind_of(Integer)
@rational.truncate(-1).should be_kind_of(Integer)
end
it "moves the truncation point n decimal places left" do
@rational.truncate(-3).should == 0
@rational.truncate(-2).should == 300
@rational.truncate(-1).should == 310
end
end
describe "with a precision > 0" do
it "returns a Rational" do
@rational.truncate(1).should be_kind_of(Rational)
@rational.truncate(2).should be_kind_of(Rational)
end
it "moves the truncation point n decimal places right" do
@rational.truncate(1).should == Rational(1571, 5)
@rational.truncate(2).should == Rational(7857, 25)
@rational.truncate(3).should == Rational(62857, 200)
end
end
describe "with an invalid value for precision" do
it "raises a TypeError" do
-> { @rational.truncate(nil) }.should raise_error(TypeError, "not an integer")
-> { @rational.truncate(1.0) }.should raise_error(TypeError, "not an integer")
-> { @rational.truncate('') }.should raise_error(TypeError, "not an integer")
end
it "does not call to_int on the argument" do
object = Object.new
object.should_not_receive(:to_int)
-> { @rational.truncate(object) }.should raise_error(TypeError, "not an integer")
end
end
end
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