Add info tooltip to inlay hints

src/FsAutoComplete/FsAutoComplete.Lsp.fs

@@ -2571,6 +2571,40 @@ type FSharpLspServer(state: State, lspClient: FSharpLspClient) =
             showParameterHints = config.InlayHints.parameterNames
           )
 
+        let getTooltip (h: InlayHints.Hint) =
+          let hideTypeAnnotations = "fsharp.inlayHints.hideTypeAnnotations"
+          let hideParameterNames = "fsharp.inlayHints.hideParameterNames"
+          let hideAll = "fsharp.inlayHints.hideAll"
+          let setToToggle = "fsharp.inlayHints.setToToggle"
+          let disableLongTooltip = "fsharp.inlayHints.disableLongTooltip"
+
+          if config.InlayHints.disableLongTooltip then
+            h.Tooltip |> Option.map (InlayHintTooltip.String)
+          else
+            let lines = ResizeArray()
+
+            let hideCommand =
+              match h.Kind with
+              | InlayHints.HintKind.Type -> hideTypeAnnotations
+              | InlayHints.HintKind.Parameter -> hideParameterNames
+
+            lines.Add $"To hide these hints, [click here](command:{hideCommand})."
+            lines.Add $"To hide *ALL* hints, [click here](command:{hideAll})."
+
+            // We don't have access to generic VSCode config so we don't know what inlay hints mode is used
+            // if not isSetToToggle && toggleSupported then
+            lines.Add
+              $"Hints can also be hidden by default, and shown when Ctrl/Cmd+Alt is pressed. To do this, [click here](command:{setToToggle})."
+
+            lines.Add $"Finally, to dismiss this long tooltip forever, [click here](command:{disableLongTooltip})."
+
+            h.Tooltip
+            |> Option.iter (fun t ->
+              lines.Add ""
+              lines.Add(t))
+
+            String.concat "\n" lines |> markdown |> InlayHintTooltip.Markup |> Some
+
         let hints: InlayHint[] =
           hints
           |> Array.map (fun h ->
@@ -2590,7 +2624,7 @@ type FSharpLspServer(state: State, lspClient: FSharpLspClient) =
                     { Range = fcsPosToProtocolRange insertion.Pos
                       NewText = insertion.Text })
                   |> Some
-              Tooltip = h.Tooltip |> Option.map (InlayHintTooltip.String)
+              Tooltip = getTooltip h
               PaddingLeft =
                 match h.Kind with
                 | InlayHints.HintKind.Type -> Some true

src/FsAutoComplete/LspHelpers.fs

@@ -590,7 +590,8 @@ type CodeLensConfigDto =
 
 type InlayHintDto =
   { typeAnnotations: bool option
-    parameterNames: bool option }
+    parameterNames: bool option
+    disableLongTooltip: bool option }
 
 type FSharpConfigDto =
   { AutomaticWorkspaceInit: bool option
@@ -641,11 +642,13 @@ type CodeLensConfig =
 
 type InlayHintsConfig =
   { typeAnnotations: bool
-    parameterNames: bool }
+    parameterNames: bool
+    disableLongTooltip: bool }
 
   static member Default =
     { typeAnnotations = true
-      parameterNames = true }
+      parameterNames = true
+      disableLongTooltip = true }
 
 type FSharpConfig =
   { AutomaticWorkspaceInit: bool
@@ -774,7 +777,8 @@ type FSharpConfig =
         | None -> InlayHintsConfig.Default
         | Some ihDto ->
           { typeAnnotations = defaultArg ihDto.typeAnnotations true
-            parameterNames = defaultArg ihDto.parameterNames true } }
+            parameterNames = defaultArg ihDto.parameterNames true
+            disableLongTooltip = defaultArg ihDto.disableLongTooltip true } }
 
 
   /// called when a configuration change takes effect, so None-valued members here should revert options
@@ -842,7 +846,8 @@ type FSharpConfig =
         | None -> InlayHintsConfig.Default
         | Some ihDto ->
           { typeAnnotations = defaultArg ihDto.typeAnnotations x.InlayHints.typeAnnotations
-            parameterNames = defaultArg ihDto.parameterNames x.InlayHints.parameterNames } }
+            parameterNames = defaultArg ihDto.parameterNames x.InlayHints.parameterNames
+            disableLongTooltip = defaultArg ihDto.disableLongTooltip x.InlayHints.disableLongTooltip } }
 
   member x.ScriptTFM =
     match x.UseSdkScripts with

test/FsAutoComplete.Tests.Lsp/Helpers.fs

@@ -210,7 +210,8 @@ let defaultConfigDto: FSharpConfigDto =
     InlayHints =
       Some
         { typeAnnotations = Some true
-          parameterNames = Some true } }
+          parameterNames = Some true
+          disableLongTooltip = Some true } }
 
 let clientCaps: ClientCapabilities =
   let dynCaps: DynamicCapabilities = { DynamicRegistration = Some true }

test/FsAutoComplete.Tests.Lsp/InlayHintTests.fs

@@ -176,8 +176,9 @@ module private LspInlayHints =
       let mkDummyEdits o = o |> Option.bind (fun _ -> Some [||])
       let ignoreData (hint: InlayHint) = { hint with Data = None }
 
+      // we remove edits and tooltips because they are too hard atm.
       let actualWithoutEdits =
-        { actual with TextEdits = mkDummyEdits actual.TextEdits }
+        { actual with TextEdits = mkDummyEdits actual.TextEdits; }
         |> ignoreData
 
       let expectedWithoutExpected =