definePlugin() — vite Function Reference

Source Code

packages/vite/src/node/plugins/define.ts lines 14–205

export function definePlugin(config: ResolvedConfig): Plugin {
  const isBundled = config.isBundled
  const isBuild = config.command === 'build'
  const isBuildLib = isBuild && config.build.lib

  // ignore replace process.env in lib build
  const processEnv: Record<string, string> = {}
  if (!isBuildLib) {
    const nodeEnv = process.env.NODE_ENV || config.mode
    Object.assign(processEnv, {
      'process.env': `{}`,
      'global.process.env': `{}`,
      'globalThis.process.env': `{}`,
      'process.env.NODE_ENV': JSON.stringify(nodeEnv),
      'global.process.env.NODE_ENV': JSON.stringify(nodeEnv),
      'globalThis.process.env.NODE_ENV': JSON.stringify(nodeEnv),
    })
  }

  // during dev, import.meta properties are handled by importAnalysis plugin.
  const importMetaKeys: Record<string, string> = {}
  const importMetaEnvKeys: Record<string, string> = {}
  const importMetaFallbackKeys: Record<string, string> = {}
  if (isBuild) {
    importMetaKeys['import.meta.hot'] = `undefined`
  }
  if (isBundled) {
    for (const key in config.env) {
      const val = JSON.stringify(config.env[key])
      importMetaKeys[`import.meta.env.${key}`] = val
      importMetaEnvKeys[key] = val
    }
    // these will be set to a proper value in `generatePattern`
    importMetaKeys['import.meta.env.SSR'] = `undefined`
    importMetaFallbackKeys['import.meta.env'] = `undefined`
  }

  function generatePattern(environment: Environment) {
    const keepProcessEnv = environment.config.keepProcessEnv

    const userDefine: Record<string, string> = {}
    const userDefineEnv: Record<string, any> = {}
    for (const key in environment.config.define) {
      userDefine[key] = handleDefineValue(environment.config.define[key])

      // make sure `import.meta.env` object has user define properties
      if (isBuild && key.startsWith('import.meta.env.')) {
        userDefineEnv[key.slice(16)] = environment.config.define[key]
      }
    }

    const define: Record<string, string> = {
      ...(keepProcessEnv ? {} : processEnv),
      ...importMetaKeys,
      ...userDefine,
      ...importMetaFallbackKeys,
    }

    // Additional define fixes based on `ssr` value
    const ssr = environment.config.consumer === 'server'

    if ('import.meta.env.SSR' in define) {
      define['import.meta.env.SSR'] = ssr + ''
    }
    if ('import.meta.env' in define) {
      define['import.meta.env'] = importMetaEnvMarker
    }

    const importMetaEnvVal = serializeDefine({
      ...importMetaEnvKeys,
      SSR: ssr + '',
      ...userDefineEnv,
    })

    // Create regex pattern as a fast check before running esbuild
    const patternKeys = Object.keys(userDefine)
    if (!keepProcessEnv && Object.keys(processEnv).length) {
      patternKeys.push('process.env')
    }
    if (Object.keys(importMetaKeys).length) {
      patternKeys.push('import.meta.env', 'import.meta.hot')