Test Asynchronous Code
Explore how to effectively test asynchronous code in Angular applications using Jasmine. Understand async/await syntax and Promise handling to write tests that wait for asynchronous operations, ensuring accurate and dependable test results.
We'll cover the following...
We'll cover the following...
Asynchronous code runs as a callback function, for example, after a timeout or interval. The best way to run asynchronous code in modern JavaScript is using the async/await notation. Jasmine makes this easy to test. Look at the example below, where we await the result of the loadPosts method before making our expectations.
function loadPosts() {
return new Promise(resolve => {
setTimeout(() => {
resolve([{
id: 1,
title: 'First post',
content: 'This is my first post',
}]);
}, 2000);
});
}
describe('Blog page tests', () => {
it('Returns users created in past year', async () => {
let posts;
posts = await loadPosts();
expect(posts.length).toEqual(1);
expect(posts).toEqual([{
id: 1,
title: 'First post',
content: 'This is my first post',
}]);
});
});The async/await syntax
In this example, we have a loadPosts ...