Exploring Extreme Programming
Recursion means you define something in terms of itself. Some data fits naturally with recursion, e.g., trees. We’ll look at how to use TDD with recursion. We’ll use a tree for our running example. A (binary) tree is either a leaf, Continue reading TDD with Recursion
There’s a tension when you introduce new objects: type checking can help, but it often gets in the way while you’re exploring. If your language supports it, typealias can smooth the transition from untyped to typed. Typealias In Swift, Kotlin, Continue reading Typealias for TDD
Loop unrolling is a performance optimization where you repeat the inside of a loop to reduce the looping overhead. It’s also a way to get rid of loops, and we’ll look at an example from a test. While ⇒ If-While Continue reading Loop Unrolling: While ⇒ If-While
Coupling occurs when one part of a system depends on another part. That is, if one part changes, the other must be adjusted too. Lambda expressions can reduce coupling by needing to refer to fewer things. Dependencies on Objects Consider Continue reading Lambda to Reduce Coupling
Last time (“Extracting” in References), we looked at why you’d use parameterized tests, to reduce duplication, improve clarity, and improve test quality. This time we’ll look at an example parameterized test in three languages: Java, Kotlin, and Swift. Java Example Continue reading Example Parameterized Tests: Java, Kotlin, and Swift
Duplication across tests may not be as harmful as duplication in production code, but a parameterized unit test can reduce duplication and help us create better tests. Judging Tests – The Pause Spotting duplication in tests is like spotting it Continue reading Extracting Parameterized Unit Tests
When we create test data in TDD, we do it to drive out new capabilities. But all test data is not of the same value. If your data has the wrong symmetry, it can mislead you about what’s working. Object Continue reading Avoid Irrelevant Symmetry!
When working with objects, there are different ways you can make them interact. We’ll take a quick look at a variety of connections, what’s needed to test them, and some alternatives you might consider. The connections below are in generally Continue reading Testing Objects and Relationships
Some refactorings (e.g., Extract Method or Extract Class) introduce new elements. Should you revise the tests to take these into account? The classic consultant’s answer applies: It depends. The obvious next question is “Depends on what?”, and we’ll explore some Continue reading Revise Tests While Refactoring? It Depends
Authorization is the process of deciding whether to allow a user can access or use some resource. (Don’t confuse it with authentication, the process of deciding whether a user is who they claim to be.) TDD and Authorization From a Continue reading Authorization – TDD Patterns