require_relative '../../spec_helper' require_relative 'fixtures/classes' describe "Math.log2" do it "returns a float" do Math.log2(5.79).should be_close(2.53356334821451, TOLERANCE) end it "returns the natural logarithm of the argument" do Math.log2(1.1).should be_close(0.137503523749935, TOLERANCE) Math.log2(3.14).should be_close(1.6507645591169, TOLERANCE) Math.log2((2**101+45677544234809571)).should be_close(101.00000000000003, TOLERANCE) Math.log2((2**10001+45677544234809571)).should == 10001.0 Math.log2((2**301+45677544234809571)).should == 301.0 end it "raises an Errno::EDOM if the argument is less than 0" do lambda { Math.log2(-1e-15) }.should raise_error( Math::DomainError) end it "raises a TypeError if the argument cannot be coerced with Float()" do lambda { Math.log2("test") }.should raise_error(TypeError) end it "raises a TypeError if passed a numerical argument as a string" do lambda { Math.log2("1.0") }.should raise_error(TypeError) end it "returns NaN given NaN" do Math.log2(nan_value).nan?.should be_true end it "raises a TypeError if the argument is nil" do lambda { Math.log2(nil) }.should raise_error(TypeError) end it "accepts any argument that can be coerced with Float()" do Math.log2(MathSpecs::Float.new).should be_close(0.0, TOLERANCE) end end