Websocket i/o timeout fix

[RobinCPel]

Description

When configuring a ping-pong interval on a web socket, it requires each web socket connection to send pings, and receive pongs. To make sure that gqlgen receives the pongs in time, a read deadline is set on the websocket connection. This functions fine as long as the graphql-transport-ws sub protocol is used. However, when using the graphql-ws sub protocol, it causes i/o timeout errors.

The reason that there are timeout errors when graphql-ws is used with a configured ping-pong interval is quite simple; graphql-ws does not support ping-pong messages.

So, to fix this, we just disable the whole ping-pong mechanism when using graphql-ws!

What does this PR exactly do?

• Fixes a typo (pingMesageType => pingMessageType)
• Slightly refactors the code in the websocket_graphqlws.go file to look more like the code in the websocket_graphql_transport_ws.go file (for the sake of consistency)
• Added two extra if statements in the websocket code that make sure that the keepAlive messages, as well as the ping messages, only get send when their corresponding sub protocol is selected (keep-alive => graphql-transport-ws, ping => graphql-ws)

Some extra details

The full server error is read tcp x.x.x.x:x->x.x.x.x:x: i/o timeout, and the full client error is invalid close code.

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I have:

• Added tests covering the bug / feature (see testing)

Not needed:

• Updated any relevant documentation (see docs)

[coveralls]

Coverage decreased (-0.1%) to 74.294% when pulling 0ede73a on RobinCPel:websocket-io-timeout-fix into d7da5b0 on 99designs:master.

[soenkehahn]

We also just (independently of @RobinCPel) ran into this exact bug. Thanks a lot for putting up the PR, @RobinCPel! We would love to see this merged!

[StevenACoffman]

Thanks!