Type class constraint inserted as last line in source file

[runeksvendsen]

I'm using the haskell.haskell VSCode plugin (v1.1.0) with VSCode 1.48.1.

When I use the Quick Fix Add <constraint> to the context of the type signature for <function> the constraint(s) are inserted in the bottom of the source file. Please see attached screen recording for an illustration of the issue.

[jhrcek]

Hello, I'm also hitting this issue and couple of other odd behaviors with this context action.
I created a simple reproducer repository https://github.com/jhrcek/hls-add-to-context-broken

Here's a gif illustrating two issues I'm hitting with this feature:

Info about my environment:

$ haskell-language-server --probe-tools
haskell-language-server version: 0.4.0.0 (GHC: 8.8.3) (PATH: /home/jhrcek/.local/bin/haskell-language-server) (GIT hash: b43a8cd78d10d77184a895293d766a0fbceb5573)
Tool versions found on the $PATH
cabal:		3.2.0.0
stack:		2.3.3
ghc:		8.10.2

Could someone please take a look at this?
EDIT:
looks like the implementation of this feature lives in ghcide repo: https://github.com/haskell/ghcide/blob/4937586a2d356156a37f8611b5fa3ff8ece56093/src/Development/IDE/Plugin/CodeAction.hs#L689-L738