Adding ping message and pong event to RTM client

[gaspardpetit]

Signed-off-by: Gaspard Petit gaspard.petit@eidosmontreal.com

Summary

It seems like the ping and pong message and event are currently missing from the RTM java client. This change makes it possible to sendMessage a PingMessage and subscribe to PongEvent

In theory, the PingMessage could contain any field desired - I am not sure how that can easily be handled especially when reading back the PongEvent without special handling, but most people should be happy with just a time field to check how long it took for Slack to respond.

(Background on this change - I am currently investigating with the RTM client gets disconnected after a long period of idle time. I suspect sending periodic ping will either keep the websocket alive or will help the client detect when it was disconnected as it will fail to send the ping.

Requirements (place an x in each [ ])

• I've read and understood the Contributing Guidelines and have done my best effort to follow them.
• I've read and agree to the Code of Conduct.

[codecov]

Codecov Report

Merging #459 into master will increase coverage by 0.06%.
The diff coverage is n/a.

@@             Coverage Diff              @@
##             master     #459      +/-   ##
============================================
+ Coverage     83.59%   83.65%   +0.06%     
- Complexity     2386     2387       +1     
============================================
  Files           250      250              
  Lines          6442     6442              
  Branches        590      590              
============================================
+ Hits           5385     5389       +4     
+ Misses          694      690       -4     
  Partials        363      363              

Impacted Files	Coverage Δ	Complexity Δ
...pi/methods/metrics/impl/RedisMetricsDatastore.java	89.50% <0.00%> (+2.46%)	38.00% <0.00%> (+1.00%)

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[seratch]

👋 Thanks again! I will check this later when I have a chance. Can you add an integration test here to help me verify the behavior more easily (also for future maintenance)?
https://github.com/slackapi/java-slack-sdk/blob/v1.0.7/slack-api-client/src/test/java/test_with_remote_apis/methods/rtm_Test.java

[seratch]

You don't need to run any other tests under the package (they require some preparations).

[gaspardpetit]

Thank you for pointing me to the right place to add an integration test. It allowed me to fix the PongEvent which was expecting id instead of reply_to.

I am not very familiar with lombok (although finding it very convenient!); it generated getReply_to and setReply_to instead of getReplyTo and setReplyTo for this field. Do you know if there is a way to configure it so it handles snake_case correctly?

[gaspardpetit]

Also, as a side note, I am >24h in and so far, pinging every 30 seconds has maintained my websocket connection opened with Slack with no other interaction. Generally, my connection drops after 6-10 hours. Perhaps periodic ping should be provided as a built-in feature of the RTM client?

[seratch]

Can you define this field as private Long replyTo (camelCase + no need to have final for this) instead? Lombok generates Long getReplyTo() and void setReplyTo(Long) for you.

Regarding the conversion from snake_cased JSON keys, Gson in this project automatically translates snake_case to camelCase. https://github.com/slackapi/java-slack-sdk/blob/v1.0.7/slack-api-client/src/main/java/com/slack/api/rtm/RTMEventsDispatcherImpl.java#L53

[gaspardpetit]

Thanks - good to know!

[seratch]

Also, as a side note, I am >24h in and so far, pinging every 30 seconds has maintained my websocket connection opened with Slack with no other interaction. Generally, my connection drops after 6-10 hours. Perhaps periodic ping should be provided as a built-in feature of the RTM client?

That's fair enough. Actually, the Python SDK does.
https://github.com/slackapi/python-slackclient/blob/v2.6.0rc2/slack/rtm/client.py#L51-L53

If you have time to work on it, it'd be greatly appreciated. Of course, I can work on it after merging this.

[seratch]

I've applied the code formatter and tweaked the test. ac2a010

Thanks for your contribution again!