Ensure exit notification is sent before closing connection

[dsherret]

Currently the exit notification is not sent because the connection gets closed before the message is sent (at least on my machine in WSL). This change waits for the exit notification to be sent before closing the connection.

Fixes #726 (exit notification not received part).

[dbaeumer]

Good catch. Thanks for the PR.

[bknaysi]

Hello @dbaeumer and @dsherret, the fix doesn't appear to be in the 7.0.0 client release or 7.1.0.next.5 tag. When do you think there will be a client release at version 7.0.0 or higher containing this fix?

[dbaeumer]

The fix is in the 8.x-next.y release of the library

[bknaysi]

@dbaeumer Thanks for the reply. It looks like 8.x-next.y requires the 3.17.0 LSP Protocol. However, there doesn't exist an LSP4J release supporting it yet, which we use to implement our server. Would it be possible for our client to use 8.x-next.y while our server only supports the 3.16.0 LSP Protocol? I'm not sure which direction the backwards compatibility exist. For example, could a client on an older protocol work with a server on a newer protocol? Likewise, could a server on an older protocol work with a client on a newer protocol?

If the later is not true, it would be amazing if this exit notification fix could be added to the future 7.1.0 release. I'm not sure we'll want to adopt any transitory next releases, but we can wait until another official one.

[dbaeumer]

I think the 8.x-next.y client should be able to talk to a 3.16 server. The protocol is compatible if the server correctly handles capability flags.

[bknaysi]

I think we'll wait for the official 8.0.0 release before adopting it into our product, but it's good to know they should be compatible. In general, how stable are the intermittent -next releases?

[dbaeumer]

I usually adopt them in ESLint. The proposed feature might still change. All the other stuff is fairly stable.