Add "Add type annotation to parameter" refactoring + remove dangling file lost in recent refactorings (#10937)

Co-authored-by: Chet Husk <[email protected]>

Author: cartermp

src/fsharp/service/FSharpParseFileResults.fs

@@ -359,6 +359,50 @@ type FSharpParseFileResults(diagnostics: FSharpDiagnostic[], input: ParsedInput,
                         None
             })
         result.IsSome
+
+    member _.IsTypeAnnotationGivenAtPosition pos =
+        let result =
+            SyntaxTraversal.Traverse(pos, input, { new SyntaxVisitorBase<_>() with 
+                member _.VisitExpr(_path, _traverseSynExpr, defaultTraverse, expr) =
+                    match expr with
+                    | SynExpr.Typed (_expr, _typeExpr, range) when Position.posEq range.Start pos ->
+                        Some range
+                    | _ -> defaultTraverse expr
+
+                override _.VisitSimplePats(_path, pats) =
+                    match pats with
+                    | [] -> None
+                    | _ ->
+                        let exprFunc pat =
+                            match pat with
+                            | SynSimplePat.Typed (_pat, _targetExpr, range) when Position.posEq range.Start pos ->
+                                Some range
+                            | _ ->
+                                None
+
+                        pats |> List.tryPick exprFunc
+
+                override _.VisitPat(_path, defaultTraverse, pat) =
+                    match pat with
+                    | SynPat.Typed (_pat, _targetType, range) when Position.posEq range.Start pos ->
+                        Some range
+                    | _ -> defaultTraverse pat })
+        result.IsSome
+
+        member _.IsBindingALambdaAtPosition pos =
+            let result =
+                SyntaxTraversal.Traverse(pos, input, { new SyntaxVisitorBase<_>() with 
+                    member _.VisitExpr(_path, _traverseSynExpr, defaultTraverse, expr) =
+                        defaultTraverse expr
+
+                    override _.VisitBinding(_path, defaultTraverse, binding) =
+                        match binding with
+                        | SynBinding.SynBinding(_, _, _, _, _, _, _, _, _, expr, range, _) when Position.posEq range.Start pos ->
+                            match expr with
+                            | SynExpr.Lambda _ -> Some range
+                            | _ -> None
+                        | _ -> defaultTraverse binding })
+            result.IsSome
 
     /// Get declared items and the selected item at the specified location
     member _.GetNavigationItemsImpl() =

src/fsharp/service/FSharpParseFileResults.fsi

@@ -52,6 +52,12 @@ type public FSharpParseFileResults =
     /// Determines if the given position is contained within a curried parameter in a binding.
     member IsPositionContainedInACurriedParameter: pos: pos -> bool
 
+    /// Determines if the expression or pattern at the given position has a type annotation
+    member IsTypeAnnotationGivenAtPosition: pos -> bool
+
+    /// Determines if the binding at the given position is bound to a lambda expression
+    member IsBindingALambdaAtPosition: pos -> bool
+
     /// Name of the file for which this information were created
     member FileName: string