How to make LS tooltip windows "pretty" w/ colors

[jaydenseric]

If the language server returns the right type of hover contents, Nova can syntax highlight code in the tooltip:

https://microsoft.github.io/language-server-protocol/specifications/specification-3-17/#hover

There are a few ways to do it, either by making sure the content string is markdown with fenced code blocks annotated with the syntax, or like this…

LSP request:

{
  "jsonrpc": "2.0",
  "id": 442,
  "method": "textDocument\\/hover",
  "params": {
    "textDocument": {
      "uri": "file:\\/\\/[redacted]\\/foo.ts"
    },
    "position": {
      "line": 1,
      "character": 9
    }
  }
}

LSP response:

{
  "jsonrpc": "2.0",
  "id": 442,
  "result": {
    "contents": [
      {
        "language": "typescript",
        "value": "function foo(): void"
      },
      "Description."
    ],
    "range": {
      "start": {
        "line": 1,
        "character": 9
      },
      "end": {
        "line": 1,
        "character": 12
      }
    }
  }
}

Note that the Description. text isn’t displaying in the hover tooltip due to a Nova bug, see:

Nova doesn't display all editor hover content

If a LSP textDocument/hover method response field result.contents looks like this: [ { "language": "typescript", "value": "type Foo = any" }, "Description here." ] The first content item will render in the editor hover tooltip, but not the second markdown string: [Screen Shot 2021-08-18 at 12.32.06 pm] See this detailed Deno extension investigation of this Nova bug causing type JSDoc descriptions to not display on hover: