From ff6f797c9c7f2e8ece00d5409a09f61ec12642db Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Andr=C3=A9=20Slupik?= <andre.slupik@gmail.com>
Date: Thu, 19 Nov 2020 19:25:20 -0500
Subject: [PATCH] Fix unused open type declaration detection

---
 src/fsharp/service/ServiceAnalysis.fs             |  7 ++++---
 vsintegration/tests/UnitTests/UnusedOpensTests.fs | 11 ++++++++++-
 2 files changed, 14 insertions(+), 4 deletions(-)

diff --git a/src/fsharp/service/ServiceAnalysis.fs b/src/fsharp/service/ServiceAnalysis.fs
index f549065fc1cc..71dbdce532af 100644
--- a/src/fsharp/service/ServiceAnalysis.fs
+++ b/src/fsharp/service/ServiceAnalysis.fs
@@ -67,9 +67,9 @@ module UnusedOpens =
                             yield! getModuleAndItsAutoOpens true ent |]
             { OpenedModules = getModuleAndItsAutoOpens false modul }
 
-    /// Represents single open statement.
+    /// Represents a single open statement
     type OpenStatement =
-        { /// All namespaces and modules which this open declaration effectively opens, including the AutoOpen ones
+        { /// All namespaces, modules and types which this open declaration effectively opens, including the AutoOpen ones
           OpenedGroups: OpenedModuleGroup list
 
           /// The range of open statement itself
@@ -90,7 +90,8 @@ module UnusedOpens =
                     if firstId.idText = MangledGlobalName then 
                         None
                     else
-                        Some { OpenedGroups = openDecl.Modules |> List.map OpenedModuleGroup.Create
+                        let openedModulesAndTypes = List.concat [openDecl.Modules; openDecl.Types |> List.map(fun ty -> ty.TypeDefinition)]
+                        Some { OpenedGroups = openedModulesAndTypes |> List.map OpenedModuleGroup.Create
                                Range = range
                                AppliedScope = openDecl.AppliedScope }
                 | _ -> None)
diff --git a/vsintegration/tests/UnitTests/UnusedOpensTests.fs b/vsintegration/tests/UnitTests/UnusedOpensTests.fs
index 28738bfe1cb3..ba474f9561c5 100644
--- a/vsintegration/tests/UnitTests/UnusedOpensTests.fs
+++ b/vsintegration/tests/UnitTests/UnusedOpensTests.fs
@@ -808,4 +808,13 @@ open Nested
 
 let _ = f 1
 """
-    => []
\ No newline at end of file
+    => []
+
+[<Test>]
+let ``open type``() =
+    """
+open type System.Console
+
+WriteLine("Hello World")
+    """
+    => [2, (10, 24)]
\ No newline at end of file