#Rsbuild adapter reference

For setup, see the Rsbuild integration overview. This page contains the complete adapter API, configuration mapping, and debugging workflow.

#API

#withRsbuildConfig(options)

Returns a configuration function that loads or accepts Rsbuild config and converts it to Rstest configuration.

#cwd

• Type: string
• Default: process.cwd()

The cwd is passed to Rsbuild's loadConfig function. It's the working directory to resolve the Rsbuild config file.

When your Rsbuild config is in a different directory or you are running tests in a monorepo (where your process.cwd() is not your config directory), you can specify the cwd option to resolve the Rsbuild config file from a different directory.

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

#configPath

• Type: string
• Default: './rsbuild.config.ts'

Path to rsbuild config file.

#config

• Type: RsbuildConfig
• Default: undefined

The inline Rsbuild config object to convert directly. When config is provided, the adapter does not call Rsbuild's loadConfig.

If configPath is also provided, the adapter uses it as config file metadata for forceRerunTriggers and build cache dependency resolution, but the inline config still takes precedence as the config content.

import { defineConfig as defineRsbuildConfig } from '@rsbuild/core';
import { defineConfig } from '@rstest/core';
import { withRsbuildConfig } from '@rstest/adapter-rsbuild';

const rsbuildConfig = defineRsbuildConfig({
  source: {
    define: {
      __DEV__: 'true',
    },
  },
});

export default defineConfig({
  extends: withRsbuildConfig({
    config: rsbuildConfig,
  }),
});

#environmentName

• Type: string
• Default: undefined

The environment name in the environments field to use, which will be merged with the common config. Set to a string to use the environment config with a matching name.

By default, the adapter uses the common configuration from Rsbuild. If your Rsbuild config has multiple environment configurations:

// rsbuild.config.ts
export default {
  source: {
    define: {
      'process.env.NODE_ENV': '"development"',
    },
  },
  environments: {
    test: {
      source: {
        define: {
          'process.env.NODE_ENV': '"test"',
        },
      },
    },
    prod: {
      source: {
        define: {
          'process.env.NODE_ENV': '"production"',
        },
      },
    },
  },
};

You can then reference specific environment configurations in your Rstest config. Rstest will adapt the Rsbuild shared configuration and the environment configuration with a matching environmentName to Rstest format.

// For testing the 'test' environment
export default defineConfig({
  extends: withRsbuildConfig({
    environmentName: 'test',
  }),
  // test-environment-specific config
});

When you need to test multiple parts of your application with different configurations independently, you can define multiple Rstest projects. Each project can extend a specific environment configuration by setting the environmentName option.

export default defineConfig({
  projects: [
    {
      extends: withRsbuildConfig({ environmentName: 'node' }),
      include: ['tests/node/**/*.{test,spec}.?(c|m)[jt]s'],
    },
    {
      extends: withRsbuildConfig({ environmentName: 'react' }),
      include: ['tests/react/**/*.{test,spec}.?(c|m)[jt]s?(x)'],
    },
  ],
});

#modifyRsbuildConfig

• Type: (config: RsbuildConfig) => RsbuildConfig | void
• Default: undefined

Modify the Rsbuild config before it gets converted to Rstest config:

export default defineConfig({
  extends: withRsbuildConfig({
    modifyRsbuildConfig: (rsbuildConfig) => {
      delete rsbuildConfig.source?.define;
      return rsbuildConfig;
    },
  }),
});

#toRstestConfig(options)

Converts an Rsbuild config object to Rstest configuration without loading a config file. Use this when your project or framework already creates an Rsbuild config object in memory.

import type { RsbuildConfig } from '@rsbuild/core';
import { defineConfig } from '@rstest/core';
import { toRstestConfig } from '@rstest/adapter-rsbuild';

const rsbuildConfig: RsbuildConfig = {
  resolve: {
    alias: {
      '@': './src',
    },
  },
};

export default defineConfig({
  extends: toRstestConfig({
    rsbuildConfig,
  }),
});

#rsbuildConfig

• Type: RsbuildConfig

The Rsbuild config object to convert.

#configPath

• Type: string
• Default: undefined

Source file path for the provided rsbuildConfig; it does not load config from this path. The adapter uses it only to add the file to forceRerunTriggers and performance.buildCache.buildDependencies.

#environmentName

• Type: string
• Default: undefined

The environment name in the environments field to merge with the common config.

#modifyRsbuildConfig

• Type: (config: RsbuildConfig) => RsbuildConfig
• Default: undefined

Modify the merged Rsbuild config object before it gets converted to Rstest config.

#Configuration mapping

The adapter automatically maps these Rsbuild options to Rstest:

Only the fields listed below are inherited. Rsbuild options that are not listed are ignored by default, which means test-irrelevant sections such as dev, server, and html are automatically pruned during conversion.

The adapter also removes the rsbuild:type-check plugin because type checking is not part of the test runtime pipeline.

#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 withRsbuildConfig()(user);
    console.log('Extended config:', JSON.stringify(config, null, 2));
    return config;
  },
});

#Related documentation

• Rsbuild configuration overview
• Rstest configuration overview