stub keyword is required for class methods

[icy-arctic-fox]

The following does not work as expected:

double TestDouble do
  def self.add_one(value)
    value + 1
  end
end

it "adds one to the value" do
  TestDouble.add_one(2).should eq(3)
end

The test fails with an UnexpectedMessage error.

Using the stub keyword works, but this should be optional.

double TestDouble do
  stub def self.add_one(value)
    value + 1
  end
end

it "adds one to the value" do
  TestDouble.add_one(2).should eq(3)
end