Unit testing logic in Svelte - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is unit testing in Svelte?

Unit testing in Svelte means checking small parts of your app, like functions or components, to make sure they work right by themselves.

beginner

Why do we write unit tests for logic in Svelte components?

We write unit tests to catch mistakes early, make sure our code works as expected, and help us change code safely without breaking things.

intermediate

How do you test a function inside a Svelte component?

You can export the function from the component and import it in your test file, then write tests to check if it returns the right results for different inputs.

beginner

What tool is commonly used for unit testing Svelte logic?

Vitest or Jest are popular tools to run unit tests for Svelte logic because they are fast and easy to set up.

intermediate

What does a good unit test for logic include?

A good unit test checks one thing clearly, uses simple inputs, and expects a specific output or behavior.

What is the main goal of unit testing logic in Svelte?

A To check small parts of code work correctly

B To test the whole app at once

C To improve app design only

D To speed up the app

Unit testing focuses on small parts like functions or components to ensure they work correctly on their own.

Which tool can you use to run unit tests in Svelte projects?

A WordPress

B Photoshop

C Excel

D Vitest

Vitest is a testing tool designed for JavaScript frameworks like Svelte.

How do you test a function inside a Svelte component?

A Rewrite the function in the test file

B Test only the HTML markup

C Export the function and import it in the test file

D Use CSS to test the function

Exporting the function allows you to import and test it directly in your test files.

What should a unit test NOT do?

A Test multiple unrelated things at once

B Use simple inputs

C Test one thing clearly

D Expect a specific output

Unit tests should focus on one thing to keep tests clear and easy to understand.

Why is unit testing logic helpful when changing code?

A It makes the app load faster

B It helps catch errors early and keeps code safe

C It changes the app design automatically

D It removes all bugs without writing code

Unit tests help find mistakes early and ensure changes don't break existing code.

Explain how you would write a unit test for a simple function inside a Svelte component.

Think about how to access the function and what to check.

Describe why unit testing logic is important in Svelte development.

Consider benefits for developers and app quality.