Add a test for #1376

[pepeiborra]

The test passes, and I cannot repro the issue with VSCode, so the issue must be down to a difference in how CoC and VSCode implement the LSP spec.

I believe it worked before the lsp-1.0 upgrade, which means that something has changed between haskell-lsp and lsp in how the initial configuration is handled.

The full LSP log (see the Gist below) from the test shows that lsp-test generates a workspace/didChangeConfiguration with the formatter config. It could be that CoC doesn't send this notification, and instead expects the server to request the config. @wz1000 @bubba is it possible that haskell-lsp does request the config at startup, whereas lsp does not?

https://gist.github.com/pepeiborra/fcad435bdf8717ceeecf392549329c19

There's nothing else to do here, so this closes #1376. The next step is to either teach lsp to request the config at startup, or get CoC to send the workspace/didChangeConfiguration as VSCode does. /cc @andys8

I also took the chance to remove an unnecessary use of the AGPL flag in the test suite

[wz1000]

Ahh, I see the problem. Your diagnosis is very helpful.

VSCode doesn't actually send any config on startup with the initialize request (as I believe this is depreciated in the LSP spec), so with lsp-1.0, we stopped trying to parse the configuration from the initialization. VSCode does send a workspace/didChangeConfiguration immediately after startup, which we still do parse.

The short-term solution would be restoring the original behavior of lsp, to parse the configuration from the initial request. I will implement this today. I believe CoC must still be following the old model and including the configuration as part of initialize.

However in the long term, I believe that relying on this behavior is deprecated by the spec, and we should be requesting the config explicitly using workspace/configuration. The trouble with that is that the spec is really unclear on what the semantics of that request actually are.

microsoft/language-server-protocol#972 (comment)

[wz1000]

haskell/lsp#285