Fast, flexible, fully featured
mocking framework


Key Features

Unit Testing Simplified

JustMock integrates seamlessly with your favorite unit testing framework and makes unit testing and mocking easy and fast. By removing dependencies, JustMock lets you focus on the logic you want to verify or assert. With JustMock you can cover more code with unit testing, faster.

Mocking MsCorLib Members/Functions

Mocking .NET framework members (a.k.a. MsCorLib) can be a daunting task. But with JustMock you are able to arrange against any MsCorLib member/function (including DateTime.Now) without any additional set-up.

Intuitive API With Better Discoverability

Even beginners learn to mock quickly with the intuitive API, which allows for natural expression of mocking concepts. The JustMock fluent interface facilitates fast feature discovery and provides options only valid to the current context. JustMock comes with one fluent and easy-to-use API, whether mocking custom code or the MSCorLib.

Elevated Mocking

JustMock provides for unrestricted mocking of dependent objects, including non-virtual methods, sealed classes, static methods and classes, as well as non-public members and types. Mocking of properties like get calls, indexers and set operations is also supported. JustMock also supports mocking of all classes and methods included in the MSCorlib assembly.

As Simple as AAA

This simple pattern, Arrange, Act, Assert (AAA) makes it easy to quickly and intuitively mock objects in unit tests.

  • Configure what should be mocked (Arrange),
  • Call the methods of properties of the object (Act),
  • Check the results of action against expected values (Assert).

With AAA, there is always a single starting point and options are contextually valid. The AAA pattern helps you keep your unit tests well structured, clean and readable. And the pattern you use stays the same, regardless of what you are mocking.

Fully Profiled Automocking

JustMock makes testing legacy code easier with its intelligent, fully profiled automocking feature, which makes your unit tests more stable. Fully profiled automocking saves you time and effort by creating an instance of a class (the system under test) without having to explicitly create each individual dependency as a unique mock.

Silverlight Elevated Mocking

With Silverlight elevated mocking support, JustMock makes unit testing your Silverlight projects easier and faster. Mock everything in your Silverlight project including sealed classes, static classes, methods, properties, final methods or properties and more. Whether you are supporting a legacy Silverlight project or creating a new one.

Build Systems Integration

JustMock works seamlessly in your continuous build configuration. Run JustMock on a build server to ensure that your tests pass every time you create a new build. JustMock is now compatible with TFS, CruiseControl.NET, Team City, Jenkins and other build servers. Take a look at our documentation for more details.

Integration with Visual Studio and Other Tools

JustMock integrates seamlessly with Visual Studio 2010, 2012 and 2013 and other tools such as OpenCover, NCover, NAnt, NCrunch, PartCover, PostSharp and test runners like TestDriven.Net and the JustCode test runner. Supported testing frameworks include MsTest, NUnit, MbUnit, xUnit, and MSpec.

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JustMock Lite

JustMock Lite, the free edition of JustMock, is the preferred choice for unit testing projects written according to the SOLID principles that don’t require elevated mocking. If you're working on greenfield projects and you don’t have to deal with legacy code, then JustMock Lite is for you. The free open source mocking framework uses the same codebase for easy upgrade to the full edition. Plus, it's commercially backed with three major releases per year and continuous product improvement both by Progress Telerik and the open source community.

Learn more about JustMock Lite

Part of DevCraft

JustMock is available for purchase individually, or as a part of DevCraft - the most comprehensive HTML5 and .NET toolbox.

Gain access to the complete stack of products to help you build stunning apps twice as fast:

  • Over 550 UI controls for HTML5 and all .NET technologies
  • Five powerful productivity, code quality and debugging tools for faster development
  • Reporting and data access
More about DevCraft
Telerik DevCraft

Support and Learning

Industry-Leading Support

Expert and Timely Response

The same developers who build JustMock will answer any questions you might have, even during your trial, to make sure your project always gets delivered on time.

Contact Progress Telerik support

Have a Suggestion?

Help us make JustMock even better. Submit your feedback and ideas, request a new feature or simply "like" and follow your favorite items on the JustMock Feedback Portal.

Visit the Feedback Portal

New Features

Telerik JustMock VS 2015 Support

API Improvements

The Q1 2016 release comes with stability and usability improvements. We’ve also improved its integration with Visual Studio 2015.

JM Enhanced syntax small

Enhanced Syntax

Arrange, assert and call private members with a natural syntax.

JM Built-In Support for Async Mocks small

Async Mocks Support

Mocked methods that return Task are now automatically arranged.


I've used a series of mocking tools and I believe that the API for JustMock is the most mature that I've encountered so far. The highest praise that I can give a framework tool is to say that its semantics are readable enough that you don't think about them at all as you're reading the code, and this is true with JustMock.

Erik DietrichSoftware Developer

When isolating methods for testing gets difficult when trying to test against legacy code or databases, JustMock really starts to set itself apart. Its features such as MsCorlib, Sealed, Static, Private method and Entity Framework mocking make the seemingly untestable, testable.

Bradley BraithwaiteSoftware Developer
Contented Coder

I recently dropped another leading mocking tool in favor of JustMock. I was never happy with the other tool’s syntax but I couldn’t find anything else on the market. I’ve found JustMock is a much more pleasant experience.

Brad Irby.NET Architect and author of Reengineering .NET
Reengineering .NET

Next Steps

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