Make block comments collapsible (#14808)

Thank you for this contribution

Kevin

Author: kerams

src/Compiler/Service/ServiceStructure.fs

@@ -850,7 +850,7 @@ module Structure =
             elif line.StartsWithOrdinal("//") then Some SingleLine
             else None
 
-        let getCommentRanges (lines: string[]) =
+        let getCommentRanges trivia (lines: string[]) =
             let rec loop (lastLineNum, currentComment, result as state) (lines: string list) lineNum =
                 match lines with
                 | [] -> state
@@ -904,6 +904,18 @@ module Structure =
                 })
             |> acc.AddRange
 
+            for trivia in trivia do
+                match trivia with
+                | CommentTrivia.BlockComment m when m.StartLine <> m.EndLine ->
+                    {
+                        Scope = Scope.Comment
+                        Collapse = Collapse.Same
+                        Range = m
+                        CollapseRange = m
+                    }
+                    |> acc.Add
+                | _ -> ()
+
         //=======================================//
         //     Signature File AST Traversal      //
         //=======================================//
@@ -1107,10 +1119,10 @@ module Structure =
         | ParsedInput.ImplFile file ->
             file.Contents |> List.iter parseModuleOrNamespace
             collectConditionalDirectives file.Trivia.ConditionalDirectives sourceLines
-            getCommentRanges sourceLines
+            getCommentRanges file.Trivia.CodeComments sourceLines
         | ParsedInput.SigFile file ->
             file.Contents |> List.iter parseModuleOrNamespaceSigs
             collectConditionalDirectives file.Trivia.ConditionalDirectives sourceLines
-            getCommentRanges sourceLines
+            getCommentRanges file.Trivia.CodeComments sourceLines
 
         acc :> seq<_>