Book Image

Svelte with Test-Driven Development

By : Daniel Irvine
Book Image

Svelte with Test-Driven Development

By: Daniel Irvine

Overview of this book

Svelte is a popular front-end framework used for its focus on performance and user-friendliness, and test-driven development (TDD) is a powerful approach that helps in creating automated tests before writing code. By combining them, you can create efficient, maintainable code for modern applications. Svelte with Test-Driven Development will help you learn effective automated testing practices to build and maintain Svelte applications. In the first part of the book, you’ll find a guided walkthrough on building a SvelteKit application using the TDD workflow. You’ll uncover the main concepts for writing effective unit test cases and practical advice for developing solid, maintainable test suites that can speed up application development while remaining effective as the application evolves. In the next part of the book, you’ll focus on refactoring and advanced test techniques, such as using component mocks and writing BDD-style tests with the Cucumber.js framework. In the final part of the book, you’ll explore how to test complex application and framework features, including authentication, Svelte stores, and service workers. By the end of this book, you’ll be well-equipped to build test-driven Svelte applications by employing theoretical and practical knowledge.
Table of Contents (22 chapters)
1
Part 1: Learning the TDD Cycle
8
Part 2: Refactoring Tests and Application Code
16
Part 3: Testing SvelteKit Features

Summary

This chapter has shown you how to write an end-to-end test with Playwright and use that as a scaffold for your Vitest unit tests. The Playwright tests check that all the units are working together, and the framework is doing its job. The Vitest tests check that you are satisfying the contract required from SvelteKit, such as the load function working in the correct fashion.

You’ve also seen how TDD can be used to delay design decisions that aren’t immediately relevant, like how we hardcoded sample data rather than implement any kind of persisted database of birthdays.

In the next chapter, we’ll expand on the same ideas by implementing a SvelteKit form action, enabling you to add new birthdays to the list.