HIE sometimes doesn't update diagnostics on change

[pikajude]

I'm not sure if this is a problem with the atom plugin or with HIE itself. It's also not very reliable to repro so I'll try to give as specific info as I can.

Here's my most reliable repro:

formatUserMessage (u, dm) =
  blue "<<<" -- delete this line and save the file
    <+> dullyellow (brackets ("user" <+> docUnique u))
    <+> string (show dm)
    <>  hardline

This should introduce a parse error, but diagnostics aren't updated until I start typing (anything) in place of the deleted line.

HIE seems to always update diagnostics correctly when I add lines. When I change lines (add or remove characters to introduce nonexistent identifiers) it usually doesn't pick that up either.

[Tehnix]

There's a similar issue tracked in the VS Code extension here haskell/vscode-haskell#143. I suspect that this is an issue with either HIE or with the LSP UIs not correctly updating the outputs.

In either case, I'll await doing anything until the VS Code issue is resolved, since that will probably indicate more or less the same fix that will be required here :)