require_relative '../../spec_helper' require_relative 'fixtures/classes' describe "Math.acosh" do it "returns a float" do Math.acosh(1.0).should be_kind_of(Float) end it "returns the principle value of the inverse hyperbolic cosine of the argument" do Math.acosh(14.2).should be_close(3.345146999647, TOLERANCE) Math.acosh(1.0).should be_close(0.0, TOLERANCE) end it "raises Math::DomainError if the passed argument is less than -1.0 or greater than 1.0" do lambda { Math.acosh(1.0 - TOLERANCE) }.should raise_error(Math::DomainError) lambda { Math.acosh(0) }.should raise_error(Math::DomainError) lambda { Math.acosh(-1.0) }.should raise_error(Math::DomainError) end it "raises a TypeError if the argument cannot be coerced with Float()" do lambda { Math.acosh("test") }.should raise_error(TypeError) end it "returns NaN given NaN" do Math.acosh(nan_value).nan?.should be_true end it "raises a TypeError if the argument is nil" do lambda { Math.acosh(nil) }.should raise_error(TypeError) end it "accepts any argument that can be coerced with Float()" do Math.acosh(MathSpecs::Float.new).should == 0.0 end end describe "Math#acosh" do it "is accessible as a private instance method" do IncludesMath.new.send(:acosh, 1.0).should be_close(0.0, TOLERANCE) end end