Avoid couple partial functions in lsp-test

[jhrcek]

Was anyone able to figure out why there are sometimes timeout messages (apparently unrelated to actual code changes) of the following king in hls test suite?

Test suite tests: RUNNING...
eval
  Property checking:                                            FAIL (66.02s)
    Timed out waiting to receive a message from the server.
    Last message received:
    {
        "jsonrpc": "2.0",
        "method": "$/progress",
        "params": {
            "token": "28",
            "value": {
                "kind": "end",
                "message": "Finished indexing 5 files"
            }
        }
    }
    Use -p '/Property checking/' to rerun this test only.

U briefly checked how lsp-test works and was surprised by the amount of partial functions used.
Here's a few easy to replace occurrences of fromJust + couple hard-to-resist hlint suggestions.

[jhrcek]

It seems pointless to convert pretty-printed json bytestring to String just to print it.
Wouldn't directly printing ByteString be less resource intensive?

[michaelpj]

I have no idea, but seems sensible

[jhrcek]

updateRequestMap returns Nothing when request with given LspId is already in it.
I don't see how it makes sense to crash in such cases as opposed to returning the origial map unmodified. Similarly in the file below.

[michaelpj]

It's quite bad: that means we've somehow reused an ID which means stuff will break. So I think this probably should throw, but maybe not by using fromJust

[jhrcek]

Alright I'll play around with it locally to see if I can reproduce the me play around with how this works to see if I can reproduce the Timed out waiting to receive a message from the server. locally and then get back to this or close this.

[michaelpj]

Thanks! I do think it's a good idea to blow up somehow if we have reused ids, though.

[jhrcek]

Found this which answers my questions about test flakiness so closing this PR.