Exploring Extreme Programming
Refactoring improves the design of code without changing its observable behavior. But what is observable behavior? We’ll look at how language semantics affect that. When you devise new refactorings, you have to take semantics into account. The Simple View is Continue reading Refactoring and Programming Language Semantics
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
Several mainstream languages have added better support for lambda expressions (including lighter syntax) in the last few years. This can let you define new forms of control structures, and reduce duplication in a different way than say extracting a common Continue reading Lambda for Control Structures, a Refactoring
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
Automated refactoring tools are great, but sometimes the tool doesn’t make the best choice. We can often nudge the tool to a better choice. Why Bother? Why bother nudging? Couldn’t you do the refactoring manually just as quickly? You could Continue reading Refactoring: Forcing the Right Extract Method
In incremental development, we grow a system by adding capabilities one at a time. Our bet is that we won’t often hit a dead end, but if we do, the time we’ve already saved will let us dig our way Continue reading Disaster Strikes! A Design Dead End
How do you know if two objects are equal? One breakdown is to classify objects as value objects or reference objects. Value objects compare as equal when their component values are equal. Reference objects compare as equal only when it’s Continue reading Value Objects – TDD Patterns
A Builder (design pattern) lets you create an object piecemeal rather than requiring the data all at once. Let’s look at what’s involved in testing one into existence. Builder A builder has a constructor, methods that gather information, and a Continue reading Building a Builder – TDD Patterns
Evolutionary design is a strategy to enable incremental delivery of capabilities. Consider two delivery strategies. In one, we plan everything we need, develop, then deliver when everything is ready. In the other, an incremental strategy, we first deliver a minimal Continue reading Evolutionary Design: Techniques and Example