There’s a Catch-22 hidden in the arguments that many people use to rationalize not writing tests. The Catch A Catch-22 is a situation that you can’t escape out of due to contradictory rules or limitations. In case of automated tests for software, the arguments often go like this. At the start of the project, both developers and managers say that the project is too young and changing all the time. There’s also market pressure to get something minimal out there

I’ve written about Property-Based Testing for .NET previously. It’s a way of writing unit tests with random (but constrained) inputs. This means your tests are run multiple times with different inputs and your code is tested more thoroughly. You might even find bugs you didn’t know were there. As I’m working quite a bit with TypeScript these days, I decided to look into property-based Testing with TypeScript. At my current client, we use Mocha for our unit tests, so let’s

If you’ve been following this blog for some time, you know I develop software mostly using test-driven development AKA TDD. But while this mostly means unit tests, it shouldn’t be limited to only unit tests. At one of my current clients, we use AWS Lambda functions written in TypeScript. These are (usually) relatively small blocks of code that can be invoked by a HTTP call. The function has a very limited scope of what it can be used for, i.e.

This post was written for the NCrunch blog. You can find the original here. Unit tests help developers write better code and provide a faster way of getting feedback compared to testing manually. But unit tests are also another piece of code that must be maintained and taken care of. Unit tests can become a mess just like production code can. Here are some tips on how to improve your tests and avoid such a situation. Keep Your Tests Small

This post was written for the NCrunch blog. You can find the original here. There are many ways of testing your application or library. The test pyramid provides a good starting point to the most common types of tests—unit tests, integration tests, end-to-end tests, and manual tests. But there are other types of tests, like contract tests, load tests, smoke tests, and what we’ll be looking at in this article—property-based tests. What’s the Idea? Property-based testing is where you test

This post was written for the NCrunch blog. You can find the original here. Test-driven development is a technique to drive the development of your project. TDD enables you to verify your code, it provides confidence for refactoring, and it enables a cleaner architecture. But what if you already have an existing codebase that wasn’t developed with TDD? How can you get started with TDD in such a (legacy) project? There are several approaches to this, so let’s dive in! The Situation

This post was written for the NCrunch blog. You can find the original here. When you dive into automated testing and test-driven development, it won’t take long before you learn about the testing pyramid. If you’ve never heard of it, don’t worry. I’ll explain what it is first, then go into some variants, and finally explain how you should use it as a guide toward a quality test suite. What Is the Testing Pyramid? Mike Cohn first came up with

This post was written for the NCrunch blog. You can find the original here. In 2018, just about every developer has at least heard of test-driven development. But that doesn’t mean every team is doing it or that every project has an extensive suite of tests. It doesn’t even mean everyone likes it or believes in it. Join me as I start out with some basic facts that no one should be able to deny. From there, I’ll work towards

This post was written for the NCrunch blog. You can find the original here. I once worked at a client site where the technical lead told me not to waste time writing tests. Speed was important and writing tests was a waste of time. Besides the fact that that’s a fallacy (I write code better and faster when I include tests), it also implied I needed his permission to write tests. And it wasn’t a good time for writing tests.