---
title: "TDD Master Class Day # 3 – “What I learned today”"
url: "https://osherove.com/blog/2009/8/26/tdd-master-class-day-3-what-i-learned-today.md"
canonical: "https://osherove.com/blog/2009/8/26/tdd-master-class-day-3-what-i-learned-today.html"
published: "2009-08-26T07:48:50"
updated: "2009-08-26T07:48:50"
tags: ["Agile"]
author: "Roy Osherove"
description: "Today’s edition had two questions: what was really hard to accomplish today, and what did you learn? Good: The different isolation frameworks Swapping all instances of a type How the Isolate.IgnoreCall method really…"
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/"
---

# TDD Master Class Day \# 3 – “What I learned today”

By Roy Osherove August 26, 2009 In [Agile](https://osherove.com/blog/category/agile)

**Historical article** · Originally published August 26, 2009; technical details may be outdated.

Today’s edition had two questions: what was really hard to accomplish today, and what did you learn?

#### Good:

The different isolation frameworks

Swapping all instances of a type

How the Isolate.IgnoreCall method really works (it should be renamed! to DoNothing)

Keeping the test simple

No need to overuse isolation frameworks

Isolator stands out (easier to remember syntax)

Legacy code CAN be tested

important to recognize bloated tests (and refactoring it)

”got”  the “extract and override” pattern

Learned to use ”isolation” instead of ”mocking” frameworks

Manual stubs and mocks can really simplify tests

#### Hard:

Hard to go slow and incremental

Naming tests is still hard

Making legacy tests readable and less bloated

Creating tests that fail for the right reason

Testing legacy code

Mixed up the frameworks all the time

How to flip through docs

Override methods through a framework vs. manually

\- making the frameworks work like i want

**\- Error messages on ALL isolatoin frameworks suck** make them More like Nunit\`s error messages

\- IDE api tooltips for ALL isolation frameworks suck, including a few of Isolator

\-

## More in Agile

[All posts in Agile](https://osherove.com/blog/category/agile)

- Sep 6, 2009

    ### [Introducing 5Whys.com](https://osherove.com/blog/2009/9/6/introducing-5whyscom.html)

- Aug 31, 2009

    ### [My Videos](https://osherove.com/blog/2009/8/31/my-videos.html)

- Aug 25, 2009

    ### [TDD Course Day 2 – “What I Learned Today”](https://osherove.com/blog/2009/8/25/tdd-course-day-2-what-i-learned-today.html)

- Aug 24, 2009

    ### [One Free Ticket to my UK TDD Master class](https://osherove.com/blog/2009/8/24/one-free-ticket-to-my-uk-tdd-master-class.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).

### Social

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- LinkedIn: https://www.linkedin.com/in/osherove/

### Contact

- Contact form: https://forms.gle/jQSx5KoXvrVA1JCK7

### 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/