Function transform

playground/transform-plugin/vite.config.js:15–27

(code, id)

    }
  },
  transform(code, id) {
    if (id === file) {
      // Ensure `index.js` is reevaluated if 'plugin-dep.js' is changed
      this.addWatchFile('./plugin-dep.js')

      return `
        // Inject TRANSFORM_COUNT
        let TRANSFORM_COUNT = ${transformCount++};

        ${code}
      `
    }
  },
}

const moduleTypePlugins = [