require_relative '../../spec_helper' require_relative 'fixtures/classes' # arccosine : (-1.0, 1.0) --> (0, PI) describe "Math.acos" do before :each do ScratchPad.clear end it "returns a float" do Math.acos(1).should be_kind_of(Float ) end it "returns the arccosine of the argument" do Math.acos(1).should be_close(0.0, TOLERANCE) Math.acos(0).should be_close(1.5707963267949, TOLERANCE) Math.acos(-1).should be_close(Math::PI,TOLERANCE) Math.acos(0.25).should be_close(1.31811607165282, TOLERANCE) Math.acos(0.50).should be_close(1.0471975511966 , TOLERANCE) Math.acos(0.75).should be_close(0.722734247813416, TOLERANCE) end it "raises an Math::DomainError if the argument is greater than 1.0" do lambda { Math.acos(1.0001) }.should raise_error(Math::DomainError) end it "raises an Math::DomainError if the argument is less than -1.0" do lambda { Math.acos(-1.0001) }.should raise_error(Math::DomainError) end it "raises a TypeError if the string argument cannot be coerced with Float()" do lambda { Math.acos("test") }.should raise_error(TypeError) end it "returns NaN given NaN" do Math.acos(nan_value).nan?.should be_true end it "raises a TypeError if the argument cannot be coerced with Float()" do lambda { Math.acos(MathSpecs::UserClass.new) }.should raise_error(TypeError) end it "raises a TypeError if the argument is nil" do lambda { Math.acos(nil) }.should raise_error(TypeError) end it "accepts any argument that can be coerced with Float()" do Math.acos(MathSpecs::Float.new(0.5)).should be_close(Math.acos(0.5), TOLERANCE) end end describe "Math#acos" do it "is accessible as a private instance method" do IncludesMath.new.send(:acos, 0).should be_close(1.5707963267949, TOLERANCE) end end