Testing Documentation

Master modern testing with Svelte 5 and vitest-browser-svelte. From basic component tests to advanced E2E patterns, this guide covers everything you need to build reliable, well-tested applications.

Documentation Guide

Complete testing documentation for Svelte 5 + vitest-browser-svelte. Start with any section below - all content is dynamically generated and always up-to-date.

Fundamentals

Getting Started

Setup, installation, and your first test

API Reference

Complete testing utilities and helper functions

Test Types

Component Testing

Browser-based component testing patterns

SSR Testing

Server-side rendering test patterns

Server Testing

API routes and server function testing

E2E Testing

End-to-end testing patterns and integration validation

Advanced Patterns

Context Testing

Testing Svelte context and stores

Remote Functions Testing

Testing SvelteKit remote functions

Runes Testing

Testing Svelte 5 runes and reactivity

Testing Patterns

Integration, error handling, and performance testing patterns

Migration & Troubleshooting

Migration Guide

Migrating from @testing-library/svelte

Troubleshooting

Common issues and solutions

DevOps

CI/CD

Production-ready testing pipelines and automation

Best Practices

Advanced patterns and optimization techniques

LLM Documentation

Documentation for LLMs

We support the llms.txt convention for making documentation available to large language models and the applications that make use of them.

Available Formats

We provide documentation in two formats following the llms.txt standard:

  • LLMs Index - Standard llms.txt file with navigation links
  • Full Documentation - Complete testing documentation with all examples and patterns

Using the appropriate format helps LLMs provide more accurate assistance with less token usage, making interactions more efficient and effective.

LLMs Index Full Documentation

📚 Complete Documentation

Jump to any section to master Svelte 5 testing with vitest-browser-svelte. Each guide includes practical examples, best practices, and real-world patterns.

Fundamentals

1

Getting Started

Setup, installation, and your first test

2

API Reference

Complete testing utilities and helper functions

Test Types

1

Component Testing

Browser-based component testing patterns

2

SSR Testing

Server-side rendering test patterns

3

Server Testing

API routes and server function testing

4

E2E Testing

End-to-end testing patterns and integration validation

Advanced Patterns

1

Context Testing

Testing Svelte context and stores

2

Remote Functions Testing

Testing SvelteKit remote functions

3

Runes Testing

Testing Svelte 5 runes and reactivity

4

Testing Patterns

Integration, error handling, and performance testing patterns

Migration & Troubleshooting

1

Migration Guide

Migrating from @testing-library/svelte

2

Troubleshooting

Common issues and solutions

DevOps

1

CI/CD

Production-ready testing pipelines and automation

2

Best Practices

Advanced patterns and optimization techniques

🚀 Need something specific? All documentation pages include:

📋 Copy-paste examples 🔍 Comprehensive API coverage ♿ Accessibility patterns ⚡ Performance tips

Quick Start

Jump right in with these essential testing patterns. Copy and paste these examples to get started immediately.

Essential Imports

Core imports for testing with vitest-browser-svelte

import { describe, expect, test, vi } from 'vitest';
import { render } from 'vitest-browser-svelte';
import { page } from 'vitest-browser/context';

Your First Test

Simple component test example

import { render } from 'vitest-browser-svelte';
import { page } from 'vitest-browser/context';
import { expect, test } from 'vitest';
import Button from './button.svelte';

test('renders button with correct text', async () => {
  render(Button, { props: { text: 'Click me' } });
  
  await expect.element(page.getByRole('button')).toHaveText('Click me');
});

Component Testing

Testing component interactions and events

import { render } from 'vitest-browser-svelte';
import { page } from 'vitest-browser/context';
import { expect, test, vi } from 'vitest';
import Button from './button.svelte';

test('calls on_click when clicked', async () => {
  const on_click = vi.fn();
  render(Button, { props: { on_click } });
  
  await page.getByRole('button').click();
  expect(on_click).toHaveBeenCalled();
});

SSR Testing

Server-side rendering tests

import { render } from 'svelte/server';
import { expect, test } from 'vitest';
import Page from './+page.svelte';

test('renders page content', () => {
  const { body } = render(Page);
  expect(body).toContain('Welcome');
});

Server Testing

Testing API routes and server functions

import { expect, test } from 'vitest';
import { GET } from './+server.ts';

test('returns correct response', async () => {
  const response = await GET();
  const data = await response.json();
  
  expect(data.success).toBe(true);
});

Core Testing Principles

Our testing philosophy emphasizes reliability, accessibility, and developer experience.

100% Test Coverage

Use the "Foundation First" approach - write all describe blocks first, then implement incrementally

Real Browser Testing

Test components in actual browser environment with vitest-browser-svelte

Accessibility First

Use semantic queries and test ARIA attributes for inclusive design

Performance Focused

Test loading states, animations, and user experience patterns

Ready to Start Testing?

Explore our interactive examples and start building reliable, well-tested Svelte applications.

View Examples Component Library
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