Exploring Extreme Programming
I’m frustrated when unit tests run slowly. One way to speed them up in Xcode when developing using a simulator: isolate your model to a framework, and run your tests without a host application. Context: Developing a Swift-based app for Continue reading Run Tests Without an App — Step by Step with Xcode
Apple has introduced a new unit testing framework. It has a simpler syntax, much simpler assertions, parameterized testing, and more. Let’s take a look. You can find a bonus cheatsheet at the end of this article. Easier Syntax XCTest (the Continue reading Swift Testing – A New Unit Testing Framework
Test-Driven Development (TDD) depends on assembling well-tested parts into a trustworthy whole. Some design structures make this easier. Today, we’ll look at trees. A tree is a structure consisting of leaf and interior nodes. An interior node contains some number Continue reading Trees – Confidence in Design
The other day, Kent Beck pointed out a skill that test-driven development (TDD) relies on but doesn’t give much guidance about: “behavioral composition”. This is the skill of dividing a big behavior in such a way that we trust the Continue reading Pipelines – Confidence in Design
Some languages (e.g., Swift, C#, Java) support extension methods. These let you add new methods to an existing class, even a system class. Extension methods support testing by providing convenient improvements in control and visibility. Extension Methods I’ll show Swift Continue reading Extension Methods for TDD
An object holds state, and you observe and control it (or both) through its public fields or methods. We’ll look at techniques you can use when an object provides no direct way to observe or control it the way a Continue reading Observe and Control Objects – TDD Patterns
Code that writes code is fun in a meta sort of way, but it requires extra testing. We’ll start by considering generic systems and their tests, then look at testing for code generation. “I’d rather write programs to write programs Continue reading Code That Writes Code Needs Multi-Level Tests
For most sorting problems, we use a pre-existing algorithm. Then, our job is to create a comparator that reflects the desired order. What is Sorting? Suppose you have a sequence of items a[0]…a[n-1], and an operator “<=”. The sorted sequence Continue reading TDD for Sorting, Using Comparators
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