.env在mode文件中如何添加注释详解

NODE_ENV='production'
VUE_APP_PATH='./'
VUE_APP_RUNTIME='prod'

const dotenv = require('dotenv');
// ...
loadEnv (mode) {
    const logger = debug('vue:env')
    const basePath = path.resolve(this.context, `.env${mode ? `.${mode}` : ``}`)
    const localPath = `${basePath}.local`
    const load = envPath => {
      try {
        const env = dotenv.config({ path: envPath, debug: process.env.DEBUG })
        dotenvExpand(env)
        logger(envPath, env)
      } catch (err) {
        // only ignore error if file is not found
        if (err.toString().indexOf('ENOENT') < 0) {
          error(err)
        }
      }
    }
    load(localPath)
    load(basePath)
    // by default, NODE_ENV and BABEL_ENV are set to "development" unless mode
    // is production or test. However the value in .env files will take higher
    // priority.
    if (mode) {
      // always set NODE_ENV during tests
      // as that is necessary for tests to not be affected by each other
      const shouldForceDefaultEnv = (
        process.env.VUE_CLI_TEST &&
        !process.env.VUE_CLI_TEST_TESTING_ENV
      )
      const defaultNodeEnv = (mode === 'production' || mode === 'test')
        ? mode
        : 'development'
      if (shouldForceDefaultEnv || process.env.NODE_ENV == null) {
        process.env.NODE_ENV = defaultNodeEnv
      }
      if (shouldForceDefaultEnv || process.env.BABEL_ENV == null) {
        process.env.BABEL_ENV = defaultNodeEnv
      }
    }
  }

NODE_ENV='production'
# VUE_APP_PATH='/pc/'
VUE_APP_PATH='./'
VUE_APP_RUNTIME='prod'

"scripts": {
    "build": "vue-cli-service build --mode prod",
  },