From d48da25976ae5406eca754cb74ade7eb8f921759 Mon Sep 17 00:00:00 2001
From: Eugene Auduchinok <eugene.auduchinok@jetbrains.com>
Date: Fri, 24 May 2019 17:16:46 +0300
Subject: [PATCH 1/2] Fix unused opens false positive for record fields

---
 src/fsharp/service/ServiceAnalysis.fs | 9 +++++++++
 tests/service/ProjectAnalysisTests.fs | 8 ++++++++
 2 files changed, 17 insertions(+)

diff --git a/src/fsharp/service/ServiceAnalysis.fs b/src/fsharp/service/ServiceAnalysis.fs
index f66d372bc28..831dcc7d828 100644
--- a/src/fsharp/service/ServiceAnalysis.fs
+++ b/src/fsharp/service/ServiceAnalysis.fs
@@ -99,17 +99,26 @@ module UnusedOpens =
              | :? FSharpMemberOrFunctionOrValue as fv when fv.IsExtensionMember -> 
                 // Extension members should be taken into account even though they have a prefix (as they do most of the time)
                 true
+
              | :? FSharpMemberOrFunctionOrValue as fv when not fv.IsModuleValueOrMember -> 
                 // Local values can be ignored
                 false
+
              | :? FSharpMemberOrFunctionOrValue when su.IsFromDefinition -> 
                 // Value definitions should be ignored
                 false
+
              | :? FSharpGenericParameter -> 
                 // Generic parameters can be ignored, they never come into scope via 'open'
                 false
+
              | :? FSharpUnionCase when su.IsFromDefinition -> 
                 false
+
+             | :? FSharpField ->
+                // Record fields are used in name resolution
+                true
+
              | _ ->
                 // For the rest of symbols we pick only those which are the first part of a long ident, because it's they which are
                 // contained in opened namespaces / modules. For example, we pick `IO` from long ident `IO.File.OpenWrite` because
diff --git a/tests/service/ProjectAnalysisTests.fs b/tests/service/ProjectAnalysisTests.fs
index 08f19cbe708..9dca0cd56f6 100644
--- a/tests/service/ProjectAnalysisTests.fs
+++ b/tests/service/ProjectAnalysisTests.fs
@@ -5523,6 +5523,14 @@ type UseTheThings(i:int) =
     member x.UseSomeUsedModuleContainingActivePattern(ActivePattern g) = g
     member x.UseSomeUsedModuleContainingExtensionMember() = (3).Q
     member x.UseSomeUsedModuleContainingUnion() = A
+
+module M1 =
+    type R = { Field: int }
+
+module M2 =
+    open M1
+
+    let foo x = x.Field
 """
     let fileSource1 = FSharp.Compiler.Text.SourceText.ofString fileSource1Text
     File.WriteAllText(fileName1, fileSource1Text)

From 237e587380716e5ab7dd092d0c3b88a5116cb126 Mon Sep 17 00:00:00 2001
From: Eugene Auduchinok <eugene.auduchinok@jetbrains.com>
Date: Fri, 24 May 2019 17:27:39 +0300
Subject: [PATCH 2/2] Add record check

---
 src/fsharp/service/ServiceAnalysis.fs | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/fsharp/service/ServiceAnalysis.fs b/src/fsharp/service/ServiceAnalysis.fs
index 831dcc7d828..e4f942b657a 100644
--- a/src/fsharp/service/ServiceAnalysis.fs
+++ b/src/fsharp/service/ServiceAnalysis.fs
@@ -115,7 +115,8 @@ module UnusedOpens =
              | :? FSharpUnionCase when su.IsFromDefinition -> 
                 false
 
-             | :? FSharpField ->
+             | :? FSharpField as field when
+                     field.DeclaringEntity.IsSome && field.DeclaringEntity.Value.IsFSharpRecord ->
                 // Record fields are used in name resolution
                 true