#Rslib

This guide covers how to integrate Rstest with Rslib for seamless testing in your Rslib projects.

#Quick start

#New project

Create a new Rslib + Rstest project. Add the --tools rstest flag when creating:

npx create-rslib --template react-ts --tools rstest --dir my-project

The scaffold includes Rstest and demo tests. Run them with npm run test.

#Existing project

To add Rstest to an existing project, follow the Quick Start to install and set up test scripts.

#Reuse Rslib config

@rstest/adapter-rslib is an official adapter that allows Rstest to automatically inherit configuration from your existing Rslib config file. This ensures your test environment matches your build configuration without duplication.

#Install adapter

npm add @rstest/adapter-rslib -D

yarn add @rstest/adapter-rslib -D

pnpm add @rstest/adapter-rslib -D

bun add @rstest/adapter-rslib -D

deno add npm:@rstest/adapter-rslib -D

#Extend your config

Using the withRslibConfig function from the adapter, you can extend your Rstest configuration from the Rslib config file.

import { defineConfig } from '@rstest/core';
import { withRslibConfig } from '@rstest/adapter-rslib';

export default defineConfig({
  extends: withRslibConfig(),
  // Additional rstest-specific configuration
});

This will automatically:

• Load your rslib.config.ts file
• Map compatible Rslib options to Rstest configuration
• Merge with any additional Rstest config you provide

By default, the adapter uses process.cwd() to resolve the Rslib config. If your config lives elsewhere, set cwd:

export default defineConfig({
  extends: withRslibConfig({
    cwd: './packages/my-lib',
  }),
});

See the @rstest/adapter-rslib documentation for advanced options.

#Configuration mapping

The adapter automatically maps these Rslib options to Rstest:

#Debug config

To see the resolved configuration returned by the adapter, wrap it and log the result:

export default defineConfig({
  extends: async (user) => {
    const config = await withRslibConfig({ libId: 'react' })(user);
    console.log('Extended config:', JSON.stringify(config, null, 2));
    return config;
  },
});

#Related documentation

• @rstest/adapter-rslib documentation
• Rslib configuration overview
• Rstest configuration overview