require File.expand_path('../../../spec_helper', __FILE__)
require File.expand_path('../fixtures/classes', __FILE__)

extended_on :rubinius do
  ruby_version_is "1.8"..."1.9" do
    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)
      end

      it "raises an Errno::EDOM if the argument is less than 0" do
        lambda { Math.log2(-1e-15) }.should raise_error( Errno::EDOM)
      end

      it "raises an ArgumentError if the argument cannot be coerced with Float()" do
        lambda { Math.log2("test") }.should raise_error(ArgumentError)
      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
  end
end

ruby_version_is "1.9" do
  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)
    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 an TypeError if the argument cannot be coerced with Float()" do
      lambda { Math.log2("test") }.should raise_error(TypeError)
    end

    it "raises an 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
end