• Solutions
    • I Can Help
      • Define
      • Educate
      • Integrate
      • Advise
    • Consultation
      • Assessments
      • Design Reviews
      • Code Inspections
      • Ongoing Support
    • Training Classes
      • Training Schedule
      • On-Site Classes
      • Online Training
      • Customized Coaching and Mob Facilitation
    • Learning Roadmap
      • Developer Essentials Training
        • Agile Analysis and Design Patterns
        • Hands-On: Extreme Programming Practices
      • Scrum Framework Developer Essentials
      • Design Pattern Developer Essentials
      • Object-Oriented Analysis and Design Patterns
      • Scrum Software Developer Essentials
      • Agile Software Developer Essentials
      • Agile Software Developer Intensives
    • Speaking
      • Beyond the Legacy Code Crisis
      • Five Developer Practices for Agile Software
      • Writing High Quality, CLEAN Code
      • Essential Scrum Developer Practices
      • Improving Your Scrum Process
      • The Agile Development Advantage
    • Testimonials
    • Clients
  • Resources
    • Blog
    • My Book: Beyond Legacy Code
    • Bibliography
    • Referral Program
    • Associates
  • Contact
    • Contact Me
    • Schedule A Call
    • About
  • Schedule A Call

Avoid Over-Specifying Tests

  1. Home
  2. Blog
  3. Avoid Over-Specifying Tests

2025 Public Training Schedule

June 23 26, 2025 – Agile Analysis and Design Patterns – Half-Day Sessions Online

July 22 – 25, 2025 – Agile Analysis and Design Patterns – Half-Day Sessions Online

Register Now
Or schedule a private class
Course Descriptions
  • Developer Essentials Training
    • Agile Analysis and Design Patterns
    • Hands-On: Extreme Programming Practices
  • Object-Oriented Analysis and Design Patterns
  • Scrum Software Developer Essentials
  • Agile Software Developer Essentials
  • Agile Software Developer Intensives
Follow me on Twitter:

Follow @ToBeAgile

Blog Post Categories
  • Announcements {19}
  • Articles {2}
  • Bits and Pieces {74}
  • Blogosphere {1}
  • Bonuses {2}
  • Build in Small Batches {27}
  • Collaborate {38}
  • Create CLEAN Code {34}
  • Implement the Design Last {11}
  • Integrate Continuously {30}
  • Off-Topic but Interesting {3}
  • Rants {82}
  • Refactor Legacy Code {24}
  • Say What, Why, and for Whom Before How {22}
  • Seven Strategies {38}
  • Specify Behaviors with Tests {17}
  • Write the Test First {27}
Archives
  • 2023
  • November 2023
  • October 2023
  • September 2023
  • August 2023
  • July 2023
  • June 2023
  • May 2023
  • April 2023
  • March 2023
  • February 2023
  • January 2023
  • 2022
  • December 2022
  • November 2022
  • October 2022
  • September 2022
  • August 2022
  • July 2022
  • June 2022
  • May 2022
  • April 2022
  • March 2022
  • February 2022
  • January 2022
  • 2021
  • December 2021
  • November 2021
  • October 2021
  • September 2021
  • August 2021
  • July 2021
  • June 2021
  • May 2021
  • April 2021
  • March 2021
  • February 2021
  • January 2021
  • 2020
  • December 2020
  • November 2020
  • October 2020
  • September 2020
  • August 2020
  • July 2020
  • June 2020
  • May 2020
  • April 2020
  • March 2020
  • February 2020
  • January 2020
  • 2019
  • December 2019
  • November 2019
  • October 2019
  • September 2019
  • August 2019
  • July 2019
  • June 2019
  • May 2019
  • April 2019
  • March 2019
  • February 2019
  • January 2019
  • 2018
  • December 2018
  • November 2018
  • October 2018
  • September 2018
  • August 2018
  • July 2018
  • June 2018
  • May 2018
  • April 2018
  • March 2018
  • February 2018
  • January 2018
  • 2017
  • December 2017
  • November 2017
  • October 2017
  • September 2017
  • August 2017
  • July 2017
  • June 2017
  • May 2017
  • April 2017
  • March 2017
  • February 2017
  • January 2017
  • 2016
  • December 2016
  • November 2016
  • October 2016
  • September 2016
  • August 2016
  • July 2016
  • June 2016
  • May 2016
  • April 2016
  • March 2016
  • February 2016
  • January 2016
  • 2015
  • December 2015
  • November 2015
  • October 2015
  • September 2015
  • August 2015
  • July 2015
  • June 2015
  • May 2015
  • April 2015
  • March 2015
  • February 2015
  • January 2015
  • 2014
  • December 2014
  • November 2014
  • October 2014
  • September 2014
  • August 2014
  • July 2014
  • June 2014
  • May 2014
  • April 2014
  • March 2014
  • February 2014
  • January 2014
  • 2013
  • December 2013
  • November 2013
  • October 2013
  • September 2013
  • August 2013
  • July 2013
  • June 2013
  • May 2013
  • April 2013
  • March 2013
  • February 2013
  • January 2013
  • 2012
  • December 2012
  • Privacy Policy

    (c) 2025 To Be Agile

    • January 29, 2020
    • Specify Behaviors with Tests

    The number one problem that I see developers have when practicing test-first development that impedes them from refactoring their code is that they over-specify behavior in their tests. This leads developers to write more tests than are needed, which can become a burden when refactoring code.

    I am a big advocate of having a complete test base and even erring on the side of caution when it comes to quality engineering and software validation but that is not what we’re talking about here. What we’re talking about here are the tests that we write when we’re doing test-first development and I’m proposing that writing those tests from the perspective of specifying the behaviors that we want to create is a highly valuable way of writing tests because it drives us to think at the right level of abstraction for creating behavioral tests and that allow us the freedom to refactor our code without breaking it.

    So the question becomes how many tests are enough?

    Have you ever played the game 20 questions? Most of us have played that game at one point in our lives. One person thinks of something that could be an animal, vegetable, or mineral and then they answer yes/no questions that are asked of them. The point of the game is to ask as few questions as possible in order to accurately guess what the person is thinking. 

    This is how I think of the unit tests that I write the specified behavior as I’m doing test-first development. I ask what are the fewest tests that I need to write in order to assert the behavior I want to create. Notice that how doing this as part of the test-first methodology makes a lot of sense because we’re essentially asking what assertions to create in order for us to be driven to build the behavior to make those assertions pass.

    For the type of behavioral testing that we’re talking about when doing test-first development, our goal is to make each test unique and so we’re only testing the main scenarios. We’re writing tests for the scenarios that drive us to write the code we want to create but again that isn’t necessarily all the tests that we need. We want to add additional tests as part of our quality engineering effort and not as part of the effort of doing test-first development.

    Here’s the challenge. When I’m given only one example of a process then it can be difficult to generalize and write a good general algorithm for the process. In these situations, I’ll sometimes come up with the second scenario that I can use to refactor my first implementation into a more generalized implementation. 

    But when I do this I and up with a second test which is redundant to the first test. Some people believe that that second test is still valuable because, they reason, that since you needed it to create the production code then someone else will probably need it to understand the system in the future if they needed to recreate the code from the tests, and that makes sense. But for me that additional test is redundant and so I typically delete it or move it into a different namespace where I keep my other quality assurance tests.

    This has led me to follow a practice that I learned from Amir Kolsky, which involves separating out what he calls red tests from green tests. Green tests are kinds of tests that we write when we’re doing test-first development. We use these tests to drive us to create the behavior we want in the system. Red tests, on the other hand, are tests that we write after we write our code to validate that it is working as expected.

    Why separate out red tests from green tests? Because my green tests serve a fundamentally different purpose. They are there to act as a living specification, validating that the behaviors work as expected. Regardless of whether they are implemented in a unit testing framework or an acceptance testing framework, they are in essence acceptance tests because they’re based upon validating behaviors or acceptance criteria rather than implementation details. I call these developer tests because essentially these are the kind of tests that we write in the course of doing development. Conversely, red tests are tests I write after the code is written to lock down some implementation. Red tests are more QA tests.

    When I refactor my code, I expect that none of my green tests will break. If red tests break then that’s okay because remember, my red tests can be implementation dependent and when I change an implementation it may cause some red tests to break. But it shouldn’t break any green tests. I find that this is a valuable distinction.

    Note: This blog post is based on one of the “Seven Strategies…” sections in my book, Beyond Legacy Code: Nine Practices to Extend the Life (and Value) of Your Software.

    Previous Post: « Use Mocks to Test Workflows

    Next Post: Use Accurate Examples »

    Leave a Reply Cancel reply

    Your email address will not be published. Required fields are marked *

    Solutions

    I Can Help
    • Define
    • Educate
    • Integrate
    • Advise

    Consultation
    • Assessments
    • Design Reviews
    • Code Inspections
    • Ongoing Support

    Testimonials Clients

    Resources

    • Blog
    • My Book: Beyond Legacy Code
    • Referral Program
    • Associates


    Read my book!
    Schedule a Call

    Training

    • Training Schedule
    • Learning Roadmap
    • On-Site Classes
    • Online Training
    • Customized Coaching and Mob Facilitation

    Course Descriptions
    • Developer Essentials Training
      • Agile Analysis and Design Patterns
      • Hands-On: Extreme Programming Practices
    • Object-Oriented Analysis and Design Patterns
    • Scrum Software Developer Essentials
    • Agile Software Developer Essentials
    • Agile Software Developer Intensives

    Copyright 2025 © To Be Agile. All rights reserved. Privacy Policy.

    This website uses cookies to improve your experience. I'll assume you're ok with this, but you can opt-out if you wish. Cookie settingsACCEPT
    Privacy & Cookies Policy

    Privacy Overview

    This website uses cookies to improve your experience while you navigate through the website. Out of these cookies, the cookies that are categorized as necessary are stored on your browser as they are essential for the working of basic functionalities of the website. We also use third-party cookies that help us analyze and understand how you use this website. These cookies will be stored in your browser only with your consent. You also have the option to opt-out of these cookies. But opting out of some of these cookies may have an effect on your browsing experience.
    Necessary
    Always Enabled
    Necessary cookies are absolutely essential for the website to function properly. This category only includes cookies that ensures basic functionalities and security features of the website. These cookies do not store any personal information.
    SAVE & ACCEPT