Contract Tests - Parameterised Test Cases
June 28, 2023This is the final installment of a three-part series about contract tests. In the first blog post we’ve discussed the rationale behind contract tests. Next we’ve looked at how ...
Read more ...Contract Tests - Abstract Test Cases
April 12, 2023In the previous blog post, we’ve discussed the rationale behind contract tests. They are used for exercising those parts of an application that communicate with other parts of ...
Read more ...Contract Tests
February 1, 2023One of my favorite awesome talks of all time is Integrated Tests Are a Scam by J.B. Rainsberger. I must admit that the title has a clickbait vibe to it. However, I very muc...
Read more ...The Testing Quadrant
June 15, 2022Back in 2003, Brian Marick wrote an excellent article series about agile testing. There he described the concept of the Testing Quadrant. To my recollection this used to be a ...
Read more ...Tales Of TDD: The Big Refactoring
February 2, 2022I’ve heard that you’ve been working on this new feature for the payroll system based on the newly voted government legislation? Yes, I am. How is it going? Seems like a major...
Read more ...Implementing Approval Tests For PDF Document Generation
December 15, 2021In the previous blog post, we discussed how to use Approval Tests for verifying generated PDF documents. In this blog post I’m going to show how to extend the Approval Test li...
Read more ...Approval Tests For PDF Document Generation
October 7, 2021A while back I was confronted with a part of a legacy system that generates PDF documents. This legacy system used a well known library for generating the requested PDF files. ...
Read more ...Ignoring Tests
June 22, 2021Most test frameworks out there have the capability to disable tests. This is usually done by adding some kind of annotation that instructs the test runner to ignore an individu...
Read more ...Writing Maintainable Unit Tests In Print
April 23, 2021I’m very happy to announce that Writing Maintainable Unit Tests is also available as a paper book. Both the ebook and the paper book have been completely self-published. I must...
Read more ...Tales Of TDD: The Case Of Overused Test Doubles
March 31, 2021Do you have 15 minutes to spare? Sure, what can I do for you? Well, you know I’ve been working on that new feature we were discussing at the whiteboard last week. I’ve finishe...
Read more ...Book Launch: Writing Maintainable Unit Tests
February 17, 2021I’m very happy to announce that I’ve finished writing my first book Writing Maintainable Unit Tests. What an amazing journey it has been. I would never have thought that I woul...
Read more ...Avoid Inheritance For Test Classes
January 6, 2021Using inheritance for test classes is not a desirable thing as it introduces a number of issues. An abstract base class quite often originates from the desire to share and reus...
Read more ...How To Write Unit Tests For Logging
November 11, 2020Once in a while I get asked the question whether one should write solitary tests for logging functionality. My answer to this question is the typical consultant answer: “It dep...
Read more ...Prevent Domain Knowledge From Sneaking Into Solitary Tests
September 30, 2020Previously we discussed why solitary tests should be easy to read. Sometimes, the readability of solitary tests is affected by those developers who overcomplicate or overenginee...
Read more ...Why Solitary Tests Should Be Easy To Read
September 9, 2020Occasionally someone asks me the question whether it’s necessary to test the code of solitary tests? Usually this question is ushered by folks who are opposed to the idea of au...
Read more ...Tales Of TDD: Stressed And Always In A Hurry
August 19, 2020So I noticed that you completed that feature that we’ve been pair programming yesterday? Yes, I was a little bored yesterday evening. So I decided to continue working on it Gr...
Read more ...Dealing With Date/Time In Solitary Tests
August 4, 2020Solitary tests never cross the process boundary in which they are executed. This means that a solitary test never executes code that talks to a database, communicates across the...
Read more ...Announcing Book: Writing Maintainable Unit Tests
July 15, 2020I’m very happy to announce that the first draft of my book Writing Maintainable Unit Tests has been published on LeanPub. It’s the written counterpart of my video course, with ...
Read more ...Only Test Through Public Interfaces
July 1, 2020One of the most commonly asked questions in developer communities regarding Test-Driven Development and unit testing is whether one should write unit tests for private methods,...
Read more ...Inside-Out and Outside-In TDD
June 16, 2020Test-Driven Development is a discipline that exists for about two decades now. Unfortunately, to this very day, it is still not without controversy. Most professional developer...
Read more ...Test Double Heuristics
June 3, 2020In the previous blog post, we’ve talked about avoiding excessive specification of test doubles. This is just one in a series of “good practices” for using test doubles in solit...
Read more ...Excessive Specification of Test Doubles
May 20, 2020Previously we’ve discussed the different kinds of test doubles. By using test doubles in our solitary tests, we also introduce more coupling between the test code and the imple...
Read more ...The Boundaries of Solitary Tests
May 6, 2020When stating the definition of a solitary test, we mentioned that they have two constraints: The code being exercised by these tests never cross the process boundary in whic...
Read more ...Test Doubles
April 8, 2020In the previous blog post, we’ve talked about indirect inputs and outputs when a unit test exercises a Subject Under Test. The examples shown previously demonstrate the use of ...
Read more ...Indirect Inputs and Outputs
April 1, 2020Previously we discussed what state and behaviour verification is about. Depending on the nature of the production code that we’re designing, we might decide to apply one approa...
Read more ...State versus Behaviour Verification
March 25, 2020When reasoning about types of automated tests, I find it quite useful to reason about two different categories, namely solitary and sociable tests. Also see the test pyramid fo...
Read more ...Cascading Failures
March 18, 2020In a previous blog post, we discussed the test pyramid and why it is a useful model to reason about a healthy mix of solitary and sociable tests. I mentioned that at t...
Read more ...The Designing versus Testing Mindset
March 12, 2020Previously, we touched on two different categories of automated tests, namely solitary and sociable tests. Also we discussed how and why the test pyramid is a useful model to ...
Read more ...Why Write Maintainable Unit Tests?
March 4, 2020Last week I published my very first video course titled Writing Maintainable Unit Tests. It surely has been a very learnful experience. Going through the process of creating th...
Read more ...Announcing Video Course: Writing Maintainable Unit Tests
February 26, 2020I’m very proud to announce that my first video course has been published on Udemy. This course teaches software developers how to write maintainable and readable unit tests. It...
Read more ...The Test Pyramid
November 7, 2019In the previous blog post, we touched on two different categories of automated tests, namely solitary and sociable tests. We also mentioned that in order to build maintainable ...
Read more ...A Taxonomy Of Tests
October 8, 2019It’s more than fair to say that the terminology used in the world of automated tests can be a bit overwhelming. Software people have uncovered all sorts of tests in a wide vari...
Read more ...Fast Feedback
September 3, 2019Test-Driven Development is a discipline that exists for almost two decades now. Unfortunately, to this very day, it is still not without controversy. Most professional developer...
Read more ...Debugability Considered Useful
January 3, 2019Developers are lazy. There’s nothing new about that. We even pride ourselves on it. Sometimes being lazy is a good thing, but most of the time it’s not something we should brag ...
Read more ...Blaming Mocks For Bad Design
December 18, 2018A while back I stumbled upon this talk titled Built-in Fake Objects. After I’ve watched the first 20 minutes or so, I was so worked up that I almost threw away my iPad just out ...
Read more ...Listening to the Vital Signs of TDD
November 8, 2018People who know me personally know that I like to go for a long run on a regular basis. I sit and work at a desk all day. So as part of the work I do, labouring the codes, I go ...
Read more ...All in the Name of DRY
September 25, 2018A while back, I was doing a code review. At some point I encountered some constructs that I see quite often. While I was describing and building my case, I was thinking that I ...
Read more ...The Burden of Features in Software
November 21, 2015I’ve been removing a couple of dead features this week. You know, those features that senior people in organisations like to tell epic war stories about. Those mighty conversati...
Read more ...Premature Abstraction
October 17, 2015The first time I read the GoF book, I didn’t understand it. This was because I didn’t had a decent understanding of the principles of object-oriented programming at the time. A...
Read more ...Christmas Light Architectures Are Not That Shiny
December 17, 2010I just want to get something of my chest that is bothering me for quite some time now. It’s not going to be a rant of some sort, but merely a couple of observations for ...
Read more ...Chain of Responsibility Using Castle Windsor and a First Experience With StructureMap - Part 2
November 16, 2008In my previous post, I outlined an issue that I had with Castle Windsor for configuring multiple chains of responsibility. I want to have different ProcessConsumer classes that ...
Read more ...Chain of Responsibility Using Castle Windsor and a First Experience With StructureMap - Part 1
November 16, 2008A couple of months ago, I applied the Chain of Responsibility pattern for the very first time. I've never encountered a scenario before where applying this pattern would be a va...
Read more ...Refactoring Exercise: The Single Responsibility Principle vs Needless Complexity
October 6, 2008Ray Houston has written this post on his blog named Single-Responsibility Versus Needless Complexity. His post contains the following code sample of which he suspects that it po...
Read more ...Properties - A False Sense of Encapsulation
September 26, 2008I'm having more and more mixed feelings about properties in .NET, or accessor methods in general, as properties compile to get_xxx/set_xxx methods behind the covers. I've never ...
Read more ...Ventilation of Thoughts
September 7, 2008Earlier this week I went back to work after a refreshing (and very much needed) vacation. During this past week I participated in some interesting discussions that made me think...
Read more ...What's Wrong with a Data-Driven Approach?
August 29, 2008Suppose we are building yet-another-order-basket-application. We have the requirement for adding items to an order, otherwise the business of our entire company falls down and w...
Read more ...The Onion Architecture
July 29, 2008This is what I consider to be a good architecture for long-lived business applications and how I like to design them. Actually, our current and past two projects apply this desi...
Read more ...A Professional Software Developer Never Says ...
July 28, 2008"Let us cleanup and fix this code later so we can meet our deadline".
Read more ...Three Qualities that Every Piece of Code Should Have ...
July 28, 2008It should solve a problem and thus it must be valuable to its users. In short, it should do what it must do and simply work. It should be very easy to change. Every piece of...
Read more ...It's the little things
July 17, 2008A while ago, I wrote a blog post regarding Test Data Builders Refined. Earlier this week, I wrote a very simple base class that provides an implicit cast operator for the builde...
Read more ...Test Data Builders Refined
April 26, 2008Last year, I blogged about Test Data Builders here and here. I still use them heavily in my unit tests for creating objects with test data. Heck, I also use this pattern for flu...
Read more ...Castle Windsor vs writing your own
April 4, 2008Earlier this week I was in a meeting were someone stated that it was better to write your own IOC container than just using an existing one (the most excellent Castle Windsor in...
Read more ...On Windows Workflow and Biztalk
April 4, 2008From each of these technologies I have a book laying around on my bookshelf somewhere. For WF, I have bought Essential Windows Workflow Foundation about 1 year ago. Since then, ...
Read more ...Castle Dynamic Proxy
March 30, 2008This blog has been silent for a while, and for good reason. Besides experiencing symptoms of writer's block, I've also been playing around with a lot of new stuff (at least new...
Read more ...Test Data Builder
December 23, 2007A while ago, I blogged about using Test Data Builders as opposed to the Object Mother pattern. Here are some links to additional tips and tricks: Tricks with Test Data Builders...
Read more ...ASP.NET MVC Framework at ALT.NET Conf
October 6, 2007Scott Guthrie announced the new ASP.NET MVC framework at the Alt.Net conference today. I blogged about this earlier on. Jeffrey Palermo who is attending the conference has put s...
Read more ...Test Data Builder versus Object Mother
September 30, 2007When writing unit tests, I frequently have an issue with creating objects that contain some test data. One approach is to call the constructor of the class at hand in every test...
Read more ...Article on Dependency Injection
September 29, 2007Mark Monster has written an excellent article on Dependency Injection in the newest .NET Magazine (it's no MSDN magazine, but hey, its free of charge). Nonetheless, there are tw...
Read more ...Improving Applications Design with a Rich Domain Model
September 2, 2007This is the title of an awesome talk that Chris Richardson gave at the Spring One 2007 conference in Antwerp. You can watch this session online. He gives a really nice introduct...
Read more ...Read "Beautiful Code" and make this a better world
July 12, 2007Good code should read like a good book. Combine these two and you get a book like Beautiful Code: Leading Programmers Explain How They Think. I've had it on my wishlist for a wh...
Read more ...Persistence Ignorance. Finally!
June 5, 2007Daniel Simmons, talks about persistence ignorance and how it will be incorporated in next version(s) of the ADO.NET Entity Framework. In a previous post, I already mentioned the...
Read more ...You're not alone
May 30, 2007It seems that Jimmy Nilsson also has a lot of trouble with ASP.NET. As you know (or might not know), I'm not enjoying my experiences with ASP.NET either. Enough with the ASP.NET...
Read more ....NET Domain-Driven Design with C#: Problem-Design-Solution
April 27, 2007A while ago I blogged about Domain-Driven Design and how I like it so much. I mentioned that Tim McCarthy is writing a book that I'm pretty much looking forward to. Today he ann...
Read more ...Build a solid core
April 8, 2007Essential reading from Jean-Paul S. Boodhoo about building a solid core. This post contains a number of truths that I want to point out. Many developers need to spend more time...
Read more ...ASP.NET Model-View-Controller Framework
March 16, 2007This is just about the best thing I've heard in the last couple of years. Scott Guthrie showed a prototype of an MVC framework on the MVP Summit (ship it!). This framework can b...
Read more ...The Underlying Problems of TDD in the .NET World
March 8, 2007This post of Jeremy D. Miller hits it right on the head: In .NET development, and especially ASP.NET WebForms development, you often have to go out of your way to create testa...
Read more ...Domain-Driven Design
March 7, 2007I'm so much into Domain-Driven Design! I already read Applying Domain-Driven Design and Patterns and I just finished reading Domain-Driven Design: Tackling Compl...
Read more ...What's Wrong with ASP.NET (bis)
February 3, 2007Another perspective from Steve Eichert. He claims that developers are not leaving .NET because of what Rails is doing right, but instead because of what .NET is doing wrong. Per...
Read more ...What's wrong with ASP.NET
January 30, 2007While I was doing the dishes today, I was thinking about the programming model of ASP.NET and the fact that I don't like it (just as don't like doing the dishes). The model it u...
Read more ...Maintainable code
January 26, 2007A very nice post by Uncle Bob about rapid software development. We've all done it! Pulling together those quick & dirty hacks in order to meet our deadline. We've created so...
Read more ...
Writing Maintainable
Unit Tests
Watch The Videos
Latest articles
-
Contract Tests - Parameterised Test Cases
June 28, 2023
-
Contract Tests - Abstract Test Cases
April 12, 2023
-
Contract Tests
February 1, 2023
-
The Testing Quadrant
June 15, 2022
-
Tales Of TDD: The Big Refactoring
February 2, 2022
Tags
- .NET
- ALT.NET
- ASP.NET
- Agile
- Announcement
- Architecture
- Behavior-Driven Development
- C++
- CQRS
- Clojure
- CoffeeScript
- Community
- Concurrent Programming
- Conferences
- Continuous Integration
- Core Skills
- CouchDB
- Database
- Design Patterns
- Domain-Driven Design
- Event Sourcing
- F#
- Fluent Interfaces
- Functional Programming
- Hacking
- Humor
- Java
- JavaScript
- Linux
- Microsoft
- NHibernate
- NoSQL
- Node.js
- Object-Relational Mapping
- Open Source
- Reading
- Ruby
- Software Design
- SourceControl
- Test-Driven Development
- Testing
- Tools
- Visual Studio
- Web
- Windows
Disclaimer
The opinions expressed on this blog are my own personal opinions. These do NOT represent anyone else’s view on the world in any way whatsoever.
About
Thank you for visiting my website. I’m a professional software developer since Y2K. A blogger since Y2K+5. Author of Writing Maintainable Unit Tests. Provider of training and coaching in XP practices. Curator of the Awesome Talks list. Thinking and learning about all kinds of technologies since forever.
Latest articles
Contract Tests - Parameterised Test Cases
June 28, 2023
Contract Tests - Abstract Test Cases
April 12, 2023
Contract Tests
February 1, 2023
The Testing Quadrant
June 15, 2022
Contact information
(+32) 496 38 00 82
info@principal-it.be