I\'m using this tutorial to Fake my DbContext and test: http://refactorthis.wordpress.com/2011/05/31/mock-faking-dbcontext-in-entity-framework-4-1-with-a-generic-repository/
You can create a Fake DbContext by using Effort for EF 6+. See https://effort.codeplex.com/. Effort stands for Entity Framework Fake ObjectContext Realization Tool.
For an article with a working sample, please see http://www.codeproject.com/Tips/1036630/Using-Effort-Entity-Framework-Unit-Testing-Tool or http://www.codeproject.com/Articles/460175/Two-strategies-for-testing-Entity-Framework-Effort?msg=5122027#xx5122027xx.