Test-driving the load function

Now that we’ve decided to implement a load function that returns hardcoded birthday data for Hercules and Athena, the actual change has become very simple.

The load function is a special SvelteKit function that will be invoked when a request comes in for the given route. So, when the user navigates to the /birthdays route, SvelteKit calls the load function in the src/routes/birthdays/+page.server.js file and then renders the component in the src/routes/birthdays/+page.svelte file.

Follow these steps to create the load function using TDD:

1. Create a new Vitest test file named src/routes/birthdays/page.server.test.js and start it off as shown. We are importing the load function from a +page.server.js file that doesn’t yet exist. We call the function in our test and store the result:

   import { describe, it, expect } from 'vitest';
   import { load } from './+page.server.js';
   describe('/birthdays - load'...