vitest-browser-svelte

Render Svelte components in Vitest Browser Mode. This library follows testing-library principles and exposes only locators and utilities that encourage you to write tests that closely resemble how your Svelte components are used.

Requires vitest 4.0.0 or higher.

``tsx
import { render } from 'vitest-browser-svelte'
import { expect, test } from 'vitest'
import Component from './Component.svelte'

test('counter button increments the count', async () => {
const screen = render(Component, {
initialCount: 1,
})

await screen.getByRole('button', { name: 'Increment' }).click()

await expect.element(screen.getByText('Count is 2')).toBeVisible()
})
`

> [!NOTE]
> This library doesn't expose or use act. Instead, you should use Vitest's locators and expect.element API that have retry-ability mechanism baked in.

vitest-browser-svelte also automatically injects render and cleanup methods on the page. Example:

`ts
// vitest.config.ts
import { defineConfig } from 'vitest/config'

export default defineConfig({
test: {
// if the types are not picked up, add vitest-browser-svelte to
// "compilerOptions.types" in your tsconfig or
// import vitest-browser-svelte manually so TypeScript can pick it up
setupFiles: ['vitest-browser-svelte'],
browser: {
// ... your browser config
},
},
})
`

`tsx
import { page } from 'vitest/browser'
import Component from './Component.svelte'

test('counter button increments the count', async () => {
const screen = page.render(Component, {
initialCount: 1,
})

screen.cleanup()
})
`

Unlike @testing-library/svelte, vitest-browser-svelte cleans up the component before the test starts instead of after, so you can see the rendered result in your UI. To avoid auto-cleanup, import the render function from vitest-browser-svelte/pure.

Special thanks

- Forked from @testing-library/svelte`