Method sendPing

packages/rtm-api/src/KeepAlive.ts:162–223

* Sends a ping and manages the timer to wait for a pong.

()

   * Sends a ping and manages the timer to wait for a pong.
   */
  private sendPing(): void {
    try {
      if (this.client === undefined) {
        if (!this.isMonitoring) {
          // if monitoring stopped before the ping timer fires, its safe to return
          this.logger.debug('stopped monitoring before ping timer fired');
          return;
        }
        const error = new Error('no client found');
        (error as CodedError).code = ErrorCode.KeepAliveInconsistentState;
        throw error;
      }
      this.logger.debug('ping timer expired, sending ping');
      this.client.send('ping')
        .then((messageId) => {
          if (this.client === undefined) {
            if (!this.isMonitoring) {
              // if monitoring stopped before the ping is sent, its safe to return
              this.logger.debug('stopped monitoring before outgoing ping message was finished');
              return;
            }
            const error = new Error('no client found');
            (error as CodedError).code = ErrorCode.KeepAliveInconsistentState;
            throw error;
          }

          this.lastPing = messageId;

          this.logger.debug('setting pong timer');

          this.pongTimer = setTimeout(
            () => {
              if (this.client === undefined) {
                // if monitoring stopped before the pong timer fires, its safe to return
                if (!this.isMonitoring) {
                  this.logger.debug('stopped monitoring before pong timer fired');
                  return;
                }
                const error = new Error('no client found');
                (error as CodedError).code = ErrorCode.KeepAliveInconsistentState;
                throw error;
              }
              // signal that this pong is done being handled
              this.client.off('slack_event', this.attemptAcknowledgePong);

              // no pong received to acknowledge the last ping within the serverPongTimeout
              this.logger.debug('pong timer expired, recommend reconnect');
              this.recommendReconnect = true;
              this.emit('recommend_reconnect');
            },
            this.serverPongTimeout,
          );

          this.client.on('slack_event', this.attemptAcknowledgePong, this);
        })
        .catch((error) => {
          this.logger.error(`Unhandled error: ${error.message}. Please report to @slack/rtm-api package maintainers.`);
        });