Apply hlint suggestion from a list always applies first

[AlexeyRaga]

#Sometimes there are more than one hlint suggestion for a given line. In this case, when the light bulb is clicked, VSCode shows a popup list of options to chose from.

It looks like currently the choice doesn't matter: clicking on any fix from that list always applies the 1st suggestion.

[txsmith]

It seems like this is a problem with the way vs code sends 'apply quick fix' commands over LSP.
The message received by the HIE server does not contain any info about which fix was applied.
For example, if I have a file with the following on line 6, and apply any of the two possible fixes, this is the corresponding message sent:

q :: [Char]
q = do ("Hello World")

{
  "jsonrpc": "2.0",
  "id": 13,
  "method": "textDocument/codeAction",
  "params": {
    "textDocument": {
      "uri": "file:///home/thomas/dev/Haskell/test-project/src/Main.hs"
    },
    "range": {
      "start": {
        "line": 5,
        "character": 6
      },
      "end": {
        "line": 5,
        "character": 24
      }
    },
    "context": {
      "diagnostics": [
        {
          "range": {
            "start": {
              "line": 5,
              "character": 6
            },
            "end": {
              "line": 5,
              "character": 24
            }
          },
          "message": "Redundant do\nFound:\n  do (\"Hello World\")\nWhy not:\n  (\"Hello World\")\n",
          "severity": 3,
          "source": "hlint"
        },
        {
          "range": {
            "start": {
              "line": 5,
              "character": 9
            },
            "end": {
              "line": 5,
              "character": 24
            }
          },
          "message": "Redundant bracket\nFound:\n  (\"Hello World\")\nWhy not:\n  \"Hello World\"\n",
          "severity": 3,
          "source": "hlint"
        }
      ]
    }
  }
}

I'm not yet sure where in the extension code this could fixed though.

[AlexeyRaga]

I have been lazily investigating this issue here: haskell/haskell-ide-engine#533

[txsmith]

I've seen that :)
Thought I'd post here since I the issue seems to originate from the way vs code sends 'quick fix' messages to HIE. The extension should send which fix was chosen from the list. Right now this is not the case so HIE has no clue which hlint issue you selected to fix.

So the root of this issue is that the vs code extension does not send enough information to HIE. I think we'd need to fix that first and then change the haskell-ide-engine to accommodate this further.