README.mdx

Shared assets

There are two types of test setup you can have: global and local. The global setup applies to all tests, while the local one can be introduced on a test suite or a test case basis. I would like to include some shared assets, like styles, to apply to all component tests, which means I need a global setup.

I will start by creating a vitest.browser.setup.ts file. The naming here doesn't matter that much, but I like to keep Vitest-related files starting with vitest.*.

In that file, I will import the assets I want to include when rendering any component:

import './src/index.css'

To make Vite process this file the same way it does the rest of my application, I need to include a type reference to vite-env.d.ts:

/// <reference path="./src/vite-env.d.ts" />
import './src/index.css'

Since we added this new file, we have to tell TypeScript how it should be handled. In tsconfig.test.json, add vitest.browser.setup.ts to the compilerOptions.include array:

{
	"extends": "./tsconfig.app.json",
	"include": [
		// The setup file runs in the browser just like the test suite.
		"vitest.browser.setup.ts",
		"src/**/*",
		"src/**/*.test.ts*"
	],
	"exclude": [],
	"compilerOptions": {
		"types": ["vitest/globals", "@vitest/browser/providers/playwright"]
	}
}

Now all that remains is to tell Vitest to use this file as the global setup for the Browser Mode.

In vite.config.ts, I will provide the path to this setup file as the value for the setupFiles property on the current browser instance:

/// <reference types="vitest" />
import { defineConfig } from 'vite'
import react from '@vitejs/plugin-react'
import tailwindcss from '@tailwindcss/vite'

export default defineConfig({
	plugins: [react(), tailwindcss()],
	test: {
		globals: true,
		browser: {
			enabled: true,
			provider: 'playwright',
			instances: [
				{
					browser: 'chromium',
					setupFiles: ['./vitest.browser.setup.ts'],
				},
			],
		},
	},
})

If I run my tests now, I will see that the styles are applied to the rendered component correctly! 🎉