@stylexswc/jest

Jest transformer that enables StyleX SWC integration for JavaScript and TypeScript testing with Jest.

Overview

The @stylexswc/jest package provides a Jest transformer that integrates with the StyleX RS compiler. This allows to transform source code using StyleX during Jest tests, ensuring that styles are correctly processed and applied.

Installation

To install the package, run the following command:

npm install --save-dev @stylexswc/jest

Configuration

To use the transformer, add it to Jest configuration. Here is an example configuration:

// jest.config.js
const path = require('path');

module.exports = {
  transform: {
    '^.+\\.(ts|tsx|js|jsx|mjs|cjs|html)$': [
      '@stylexswc/jest',
      {
        rsOptions: {
          aliases: {
            '@/*': [path.join(__dirname, '*')],
          },
          unstable_moduleResolution: {
            type: 'commonJS',
          },
        },
      },
    ],
  },
  setupFilesAfterEnv: ['<rootDir>/jest.setup.js'],
  testEnvironment: 'jsdom',
};

Options

rsOptions

• Type: Partial<StyleXOptions>
• Optional
• Description: StyleX compiler options that will be passed to the transformer. For standard StyleX options, see the official StyleX documentation.

[!NOTE] New Features: The include and exclude options are exclusive to this NAPI-RS compiler implementation and are not available in the official StyleX Babel plugin.

rsOptions.include

• Type: (string | RegExp)[]
• Optional
• Description: RS-compiler Only An array of glob patterns or regular expressions to include specific files for StyleX transformation. When specified, only files matching at least one of these patterns will be transformed. Patterns are matched against paths relative to the current working directory. Supports regex lookahead/lookbehind for advanced filtering.

rsOptions.exclude

• Type: (string | RegExp)[]
• Optional
• Description: RS-compiler Only An array of glob patterns or regular expressions to exclude specific files from StyleX transformation. Files matching any of these patterns will not be transformed, even if they match an include pattern. Patterns are matched against paths relative to the current working directory. Supports regex lookahead/lookbehind for advanced filtering.

Path Filtering Examples

Include only specific directories:

{
  rsOptions: {
    include: ['src/**/*.{ts,tsx}', 'app/**/*.{ts,tsx}'],
  },
}

Exclude test files:

{
  rsOptions: {
    exclude: ['**/*.test.*', '**/*.spec.*', '**/__tests__/**'],
  },
}

Using RegExp with lookahead/lookbehind - exclude node_modules except specific packages:

{
  rsOptions: {
    // Exclude all node_modules except @stylexjs/open-props
    exclude: [/node_modules(?!\/@stylexjs\/open-props)/],
  },
}

Combined include and exclude:

{
  rsOptions: {
    include: ['src/**/*.{ts,tsx}'],
    exclude: ['**/*.test.*', '**/*.stories.*'],
  },
}

Example

Here is an example of how to use @swc/jest with other transformers:

// jest.config.js
const nextJest = require('next/jest');
const path = require('path');

const createJestConfig = nextJest({
  dir: process.cwd(),
});

const customJestConfig = {
  setupFilesAfterEnv: ['<rootDir>/jest.setup.js'],
  testEnvironment: 'jsdom',
  transform: {
    '^.+\\.(ts|tsx|js|jsx|mjs|cjs|html)$': [
      'jest-chain-transform',
      {
        transformers: [
          [
            '@stylexswc/jest',
            {
              rsOptions: {
                aliases: {
                  '@/*': [path.join(__dirname, '*')],
                },
                unstable_moduleResolution: {
                  type: 'commonJS',
                },
              },
            },
          ],
          [
            '@swc/jest',
            {
              $schema: 'https://json.schemastore.org/swcrc',
              jsc: {
                parser: {
                  syntax: 'typescript',
                  tsx: true,
                  dynamicImport: true,
                  decorators: true,
                  dts: true,
                },
                transform: {
                  react: {
                    useBuiltins: true,
                    runtime: 'automatic',
                  },
                },
                target: 'esnext',
                loose: false,
                externalHelpers: false,
                keepClassNames: true,
                baseUrl: './',
                paths: {
                  '@/*': ['./*'],
                },
              },
              module: {
                type: 'es6',
              },
              minify: false,
            },
          ],
        ],
      },
    ],
  },
};

module.exports = customJestConfig;

Real example can be found in the @stylexswc/next-example

License

This project is licensed under the MIT License. See the LICENSE file for details.