vite-plugin-testem

Vite plugin and Testem middleware helper for browser unit tests.

Install

npm install vite-plugin-testem --save-dev

You must also install a compatible Vite version (peer dependency: ^7.0.0 || ^8.0.0).

To run browser tests with Testem, install Testem in your project (optional peer dependency: ^3.20.0):

npm install testem@^3.20.0 --save-dev

vitePluginTestem(options)

Vite plugin that injects the Testem client script (/testem.js) into index.html. For TAP-style runners it can inject the usual Testem.handleConsoleMessage bridge.

Options

• framework: 'tap' (default), 'mocha', or 'none'
• injectTapBridge: override whether the TAP console bridge is injected (defaults to on when framework === 'tap')

createTestemViteMiddleware(inlineConfig)

Returns a Promise of { middleware, close }. Use middleware in Testem’s middleware array so Vite runs in middleware mode ahead of Testem’s own routes. The helper skips /testem.js, /testem/*, and /socket.io so Testem still serves its client and Socket.IO on the same origin.

Pass Vite InlineConfig fields as needed (for example root: __dirname). Set configFile: false if you do not want Vite to load vite.config.js.

Recommended: on_exit and close()

Vite’s dev server registers file watchers and keeps resources open. If you only register the middleware and exit Testem, those handles can prevent the process from exiting cleanly or leave watcher noise in the background.

Call the close() function returned with the middleware from Testem’s on_exit hook. That shuts down the Vite server the same way as stopping the CLI dev server.

Example testem.js:

const { createTestemViteMiddleware } = require('vite-plugin-testem');

let viteClose;

module.exports = async function testemConfig() {
  const { middleware, close } = await createTestemViteMiddleware({
    root: __dirname,
  });
  viteClose = close;

  return {
    middleware: [middleware],
    test_page: 'index.html',
    on_exit(config, data, callback) {
      if (!viteClose) {
        return callback(null);
      }
      viteClose()
        .then(() => callback(null))
        .catch(callback);
    },
  };
};

License

MIT