text: /*       */
  
  const Transform = require('stream').Transform
  
  export default class TemplateStream extends Transform {
    constructor (
      renderer,
      template,
      context,
    ) {
      super()
      this.started = false
      this.renderer = renderer
      this.template = template
      this.context = context || {}
      this.inject = renderer.inject
    }
  
    _transform (data, encoding, done) {
      if (!this.started) {
        this.emit('beforeStart')
        this.start()
      }
      this.push(data)
      done()
    }
  
    start () {
      this.started = true
      this.push(this.template.head(this.context))
  
      if (this.inject) {
        // inline server-rendered head meta information
        if (this.context.head) {
          this.push(this.context.head)
        }
  
        // inline preload/prefetch directives for initial/async chunks
        const links = this.renderer.renderResourceHints(this.context)
        if (links) {
          this.push(links)
        }
  
        // CSS files and inline server-rendered CSS collected by vue-style-loader
        const styles = this.renderer.renderStyles(this.context)
        if (styles) {
          this.push(styles)
        }
      }
  
      this.push(this.template.neck(this.context))
    }
  
    _flush (done) {
      this.emit('beforeEnd')
  
      if (this.inject) {
        // inline initial store state
        const state = this.renderer.renderState(this.context)
        if (state) {
          this.push(state)
        }
  
        // embed scripts needed
        const scripts = this.renderer.renderScripts(this.context)
        if (scripts) {
          this.push(scripts)
        }
      }
  
      this.push(this.template.tail(this.context))
      done()
    }
  }
  