Method #connect

deps/undici/src/lib/web/eventsource/eventsource.js:210–305

()

  }

  #connect () {
    if (this.#readyState === CLOSED) return

    this.#readyState = CONNECTING

    const fetchParams = {
      request: this.#request,
      dispatcher: this.#dispatcher
    }

    // 14. Let processEventSourceEndOfBody given response res be the following step: if res is not a network error, then reestablish the connection.
    const processEventSourceEndOfBody = (response) => {
      if (!isNetworkError(response)) {
        return this.#reconnect()
      }
    }

    // 15. Fetch request, with processResponseEndOfBody set to processEventSourceEndOfBody...
    fetchParams.processResponseEndOfBody = processEventSourceEndOfBody

    // and processResponse set to the following steps given response res:
    fetchParams.processResponse = (response) => {
      // 1. If res is an aborted network error, then fail the connection.

      if (isNetworkError(response)) {
        // 1. When a user agent is to fail the connection, the user agent
        // must queue a task which, if the readyState attribute is set to a
        // value other than CLOSED, sets the readyState attribute to CLOSED
        // and fires an event named error at the EventSource object. Once the
        // user agent has failed the connection, it does not attempt to
        // reconnect.
        if (response.aborted) {
          this.close()
          this.dispatchEvent(new Event('error'))
          return
          // 2. Otherwise, if res is a network error, then reestablish the
          // connection, unless the user agent knows that to be futile, in
          // which case the user agent may fail the connection.
        } else {
          this.#reconnect()
          return
        }
      }

      // 3. Otherwise, if res's status is not 200, or if res's `Content-Type`
      // is not `text/event-stream`, then fail the connection.
      const contentType = response.headersList.get('content-type', true)
      const mimeType = contentType !== null ? parseMIMEType(contentType) : 'failure'
      const contentTypeValid = mimeType !== 'failure' && mimeType.essence === 'text/event-stream'
      if (
        response.status !== 200 ||
        contentTypeValid === false
      ) {
        this.close()
        this.dispatchEvent(new Event('error'))
        return
      }