require_relative '../../spec_helper' require_relative 'fixtures/classes' # arcsine : (-1.0, 1.0) --> (-PI/2, PI/2) describe "Math.asin" do it "returns a float" do Math.asin(1).should be_kind_of(Float) end it "returns the arcsine of the argument" do Math.asin(1).should be_close(Math::PI/2, TOLERANCE) Math.asin(0).should be_close(0.0, TOLERANCE) Math.asin(-1).should be_close(-Math::PI/2, TOLERANCE) Math.asin(0.25).should be_close(0.252680255142079, TOLERANCE) Math.asin(0.50).should be_close(0.523598775598299, TOLERANCE) Math.asin(0.75).should be_close(0.8480620789814816,TOLERANCE) end it "raises an Math::DomainError if the argument is greater than 1.0" do lambda { Math.asin(1.0001) }.should raise_error( Math::DomainError) end it "raises an Math::DomainError if the argument is less than -1.0" do lambda { Math.asin(-1.0001) }.should raise_error( Math::DomainError) end it "raises a TypeError if the argument cannot be coerced with Float()" do lambda { Math.asin("test") }.should raise_error(TypeError) end it "returns NaN given NaN" do Math.asin(nan_value).nan?.should be_true end it "raises a TypeError if the argument is nil" do lambda { Math.asin(nil) }.should raise_error(TypeError) end it "accepts any argument that can be coerced with Float()" do Math.asin(MathSpecs::Float.new).should be_close(1.5707963267949, TOLERANCE) end end describe "Math#asin" do it "is accessible as a private instance method" do IncludesMath.new.send(:asin, 0.5).should be_close(0.523598775598299, TOLERANCE) end end