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require File.expand_path('../../../spec_helper', __FILE__)
describe "Bignum#<< with n << m" do
before(:each) do
@bignum = bignum_value() * 16
end
it "returns n shifted left m bits when n > 0, m > 0" do
(@bignum << 4).should == 2361183241434822606848
end
it "returns n shifted left m bits when n < 0, m > 0" do
(-@bignum << 9).should == -75557863725914323419136
end
it "returns n shifted right m bits when n > 0, m < 0" do
(@bignum << -1).should == 73786976294838206464
end
it "returns n shifted right m bits when n < 0, m < 0" do
(-@bignum << -2).should == -36893488147419103232
end
it "returns n when n > 0, m == 0" do
(@bignum << 0).should == @bignum
end
it "returns n when n < 0, m == 0" do
(-@bignum << 0).should == -@bignum
end
it "returns 0 when m < 0 and m == p where 2**p > n >= 2**(p-1)" do
(@bignum << -68).should == 0
end
not_compliant_on :rubinius, :jruby do
it "returns 0 when m < 0 and m is a Bignum" do
(@bignum << -bignum_value()).should == 0
end
end
deviates_on :rubinius do
it "raises a RangeError when m < 0 and m is a Bignum" do
lambda { @bignum << -bignum_value() }.should raise_error(RangeError)
end
end
it "returns a Fixnum == fixnum_max() when (fixnum_max() * 2) << -1 and n > 0" do
result = (fixnum_max() * 2) << -1
result.should be_an_instance_of(Fixnum)
result.should == fixnum_max()
end
it "returns a Fixnum == fixnum_min() when (fixnum_min() * 2) << -1 and n < 0" do
result = (fixnum_min() * 2) << -1
result.should be_an_instance_of(Fixnum)
result.should == fixnum_min()
end
it "calls #to_int to convert the argument to an Integer" do
obj = mock("4")
obj.should_receive(:to_int).and_return(4)
(@bignum << obj).should == 2361183241434822606848
end
it "raises a TypeError when #to_int does not return an Integer" do
obj = mock("a string")
obj.should_receive(:to_int).and_return("asdf")
lambda { @bignum << obj }.should raise_error(TypeError)
end
it "raises a TypeError when passed nil" do
lambda { @bignum << nil }.should raise_error(TypeError)
end
it "raises a TypeError when passed a String" do
lambda { @bignum << "4" }.should raise_error(TypeError)
end
end
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