This morning we have released v.5.0.1, new major version, to npm.

It contains a few notable changes and a new feature:

• sinon object is now a (default) sandbox, making your setup easier
• sinon.fake creates immutable fakes, lots easier to use than stub
• sinon.replace, sinon.replaceGetter, sinon.replaceSetter can be used for replacing properties with fakes (and spies and stubs)

http://sinonjs.org/guides/migrating-to-5.0