---
title: "Isolator feature focus – Advanced Debugger Support for fakes"
url: "https://osherove.com/blog/2008/10/11/isolator-feature-focus-advanced-debugger-support-for-fakes.md"
canonical: "https://osherove.com/blog/2008/10/11/isolator-feature-focus-advanced-debugger-support-for-fakes.html"
published: "2008-10-11T15:15:36"
updated: "2008-10-11T15:15:36"
tags: [".NET", "Agile", "FeatureFocus", "Typemock"]
author: "Roy Osherove"
description: "Two features that Typemock Isolator has make the debugging experience with it very different than any other isolation framework: 1) Highlight fake method during debugging When stepping into a method that is being faked…"
usage: "Licensed under CC BY 4.0 — reuse, quote and adapt with attribution (Roy Osherove, link to the original page)."
license: "https://creativecommons.org/licenses/by/4.0/"
---

# Isolator feature focus – Advanced Debugger Support for fakes

By Roy Osherove October 11, 2008 In [.NET](https://osherove.com/blog/category/net), [Agile](https://osherove.com/blog/category/agile), [FeatureFocus](https://osherove.com/blog/category/featurefocus), [Typemock](https://osherove.com/blog/category/typemock)

**Historical article** · Originally published October 11, 2008; technical details may be outdated.

Two features that [Typemock Isolator](http://www.typemock.com/) has make the debugging experience with it very different than any other isolation framework:

**1) Highlight fake method during debugging**

![WindowClipping (28)](https://osherove.com/img/wb/570ee04a_weblogs.asp.net_blogs_rosherove_WindowClipping_20_28__thumb_jzCqoA.jpg)

When stepping into a method that is being faked by the test, the method will be outlined with a nice purple line around it, notifying the user that the real method will not be called, but instead will be intercepted by Typemock Isolator.

**2) Fake method and property evaluation in the debugger does not break the test**

With other frameworks, if, during debugging, you evaluate (even by mistake, by opening a watch window for example) the value of a fake property of a method, the isolation framework will treat this action as if it was run from production code, and so you might fail the test or cause unknown behavior from the faked methods or properties.

Isolator is smart enough to detect such actions and will do two things:

- Return the fake value that was assigned to that method or property to see in the debugger
- Ignore this action as if it never happened so the test can continue as is even during debugging

## More in .NET

[All posts in .NET](https://osherove.com/blog/category/net)

- Oct 15, 2008

    ### [Use Reflection to find Methods that implement explicit interfaces](https://osherove.com/blog/2008/10/15/use-reflection-to-find-methods-that-implement-explicit-inter.html)

- Oct 12, 2008

    ### [SharpMock 0.1 ?](https://osherove.com/blog/2008/10/12/sharpmock-01.html)

- Oct 11, 2008

    ### [Art Of Unit Testing – Book done, Wiki ready](https://osherove.com/blog/2008/10/11/art-of-unit-testing-book-done-wiki-ready.html)

- Oct 6, 2008

    ### [Graphic Designer Wanted (and found)](https://osherove.com/blog/2008/10/6/graphic-designer-wanted-and-found.html)


---

## About the author

**Roy Osherove**: Senior Solutions Architect at AWS working on AI for production and AI-driven development; author of The Art of Unit Testing and Elastic Leadership, with about 20 years of consulting and training on unit testing, TDD, team leadership and continuous delivery.

### Sites

- [RobotPaper](https://robotpaper.ai/): This blog: AI patterns and anti-patterns, AI and coding agents, and engineering leadership.
- [osherove.com](https://osherove.com): Roy's personal site. Author of The Art of Unit Testing and Elastic Leadership; consulting and training on unit testing, TDD, team leadership and continuous delivery, plus about 20 years of blog posts.
- [The Art of Unit Testing](https://www.artofunittesting.com): The Art of Unit Testing, 3rd Edition (Manning): readable, maintainable, trustworthy unit tests, plus TDD workshops in C#, JavaScript, Java and Kotlin.
- [5whys.com](https://www.5whys.com): Roy's writing on software team leadership: self-organizing teams, surviving chaos, learning mode and the Elastic Leadership model.
- [Pipeline Driven](https://pipelinedriven.org): Continuous delivery and DevOps practices: build patterns, pipeline-friendly testing, DevOps metrics and enterprise DevOps.
- [Elastic Leadership](https://www.elasticleadership.com): Elastic Leadership, Roy's framework for software team leaders (survival, learning and self-organizing modes).

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### License

Licensed under CC BY 4.0 — reuse, quote and adapt with attribution (Roy Osherove, link to the original page). License: https://creativecommons.org/licenses/by/4.0/