From 4427b3b77359f65b3bfb5a147c342d5b8dbecf6c Mon Sep 17 00:00:00 2001
From: Steve Sanderson <SteveSandersonMS@users.noreply.github.com>
Date: Wed, 6 Jun 2018 11:07:01 +0100
Subject: [PATCH] Add more struct readonlyness hints

---
 .../RenderTreeDiffBuilderBenchmark.cs                           | 2 +-
 .../Rendering/BrowserRenderer.cs                                | 2 +-
 .../Components/EventHandlerInvoker.cs                           | 2 +-
 .../Components/ParameterCollectionExtensions.cs                 | 2 +-
 src/Microsoft.AspNetCore.Blazor/RenderTree/RenderTreeBuilder.cs | 2 +-
 .../RenderTree/RenderTreeDiffBuilder.cs                         | 2 +-
 src/Microsoft.AspNetCore.Blazor/Rendering/Renderer.cs           | 2 +-
 .../RazorIntegrationTestBase.cs                                 | 2 +-
 test/Microsoft.AspNetCore.Blazor.Test/RenderTreeBuilderTest.cs  | 2 +-
 .../RenderTreeDiffBuilderTest.cs                                | 2 +-
 test/Microsoft.AspNetCore.Blazor.Test/RendererTest.cs           | 2 +-
 test/shared/TestRenderer.cs                                     | 2 +-
 12 files changed, 12 insertions(+), 12 deletions(-)

diff --git a/benchmarks/Microsoft.AspNetCore.Blazor.Performance/RenderTreeDiffBuilderBenchmark.cs b/benchmarks/Microsoft.AspNetCore.Blazor.Performance/RenderTreeDiffBuilderBenchmark.cs
index 9f81a9042d..4c5dad8b10 100644
--- a/benchmarks/Microsoft.AspNetCore.Blazor.Performance/RenderTreeDiffBuilderBenchmark.cs
+++ b/benchmarks/Microsoft.AspNetCore.Blazor.Performance/RenderTreeDiffBuilderBenchmark.cs
@@ -92,7 +92,7 @@ namespace Microsoft.AspNetCore.Blazor.Performance
             {
             }
 
-            protected override void UpdateDisplay(RenderBatch renderBatch)
+            protected override void UpdateDisplay(in RenderBatch renderBatch)
             {
             }
         }
diff --git a/src/Microsoft.AspNetCore.Blazor.Browser/Rendering/BrowserRenderer.cs b/src/Microsoft.AspNetCore.Blazor.Browser/Rendering/BrowserRenderer.cs
index 0569fffd69..af2ed485e8 100644
--- a/src/Microsoft.AspNetCore.Blazor.Browser/Rendering/BrowserRenderer.cs
+++ b/src/Microsoft.AspNetCore.Blazor.Browser/Rendering/BrowserRenderer.cs
@@ -76,7 +76,7 @@ namespace Microsoft.AspNetCore.Blazor.Browser.Rendering
         }
 
         /// <inheritdoc />
-        protected override void UpdateDisplay(RenderBatch batch)
+        protected override void UpdateDisplay(in RenderBatch batch)
         {
             RegisteredFunction.InvokeUnmarshalled<int, RenderBatch, object>(
                 "renderBatch",
diff --git a/src/Microsoft.AspNetCore.Blazor/Components/EventHandlerInvoker.cs b/src/Microsoft.AspNetCore.Blazor/Components/EventHandlerInvoker.cs
index 40d58a3e29..c73d76fd2f 100644
--- a/src/Microsoft.AspNetCore.Blazor/Components/EventHandlerInvoker.cs
+++ b/src/Microsoft.AspNetCore.Blazor/Components/EventHandlerInvoker.cs
@@ -9,7 +9,7 @@ namespace Microsoft.AspNetCore.Blazor.Components
     /// <summary>
     /// A bound event handler delegate.
     /// </summary>
-    public struct EventHandlerInvoker
+    public readonly struct EventHandlerInvoker
     {
         private readonly MulticastDelegate _delegate;
 
diff --git a/src/Microsoft.AspNetCore.Blazor/Components/ParameterCollectionExtensions.cs b/src/Microsoft.AspNetCore.Blazor/Components/ParameterCollectionExtensions.cs
index d0d9f9cb04..a0e85defbf 100644
--- a/src/Microsoft.AspNetCore.Blazor/Components/ParameterCollectionExtensions.cs
+++ b/src/Microsoft.AspNetCore.Blazor/Components/ParameterCollectionExtensions.cs
@@ -30,7 +30,7 @@ namespace Microsoft.AspNetCore.Blazor.Components
         /// <param name="parameterCollection">The <see cref="ParameterCollection"/>.</param>
         /// <param name="target">An object that has a public writable property matching each parameter's name and type.</param>
         public static void AssignToProperties(
-            this ParameterCollection parameterCollection,
+            in this ParameterCollection parameterCollection,
             object target)
         {
             if (target == null)
diff --git a/src/Microsoft.AspNetCore.Blazor/RenderTree/RenderTreeBuilder.cs b/src/Microsoft.AspNetCore.Blazor/RenderTree/RenderTreeBuilder.cs
index d98602d342..23426dc10d 100644
--- a/src/Microsoft.AspNetCore.Blazor/RenderTree/RenderTreeBuilder.cs
+++ b/src/Microsoft.AspNetCore.Blazor/RenderTree/RenderTreeBuilder.cs
@@ -306,7 +306,7 @@ namespace Microsoft.AspNetCore.Blazor.RenderTree
         /// </summary>
         /// <param name="sequence">An integer that represents the position of the instruction in the source code.</param>
         /// <param name="frame">A <see cref="RenderTreeFrame"/> holding the name and value of the attribute.</param>
-        public void AddAttribute(int sequence, RenderTreeFrame frame)
+        public void AddAttribute(int sequence, in RenderTreeFrame frame)
         {
             if (frame.FrameType != RenderTreeFrameType.Attribute)
             {
diff --git a/src/Microsoft.AspNetCore.Blazor/RenderTree/RenderTreeDiffBuilder.cs b/src/Microsoft.AspNetCore.Blazor/RenderTree/RenderTreeDiffBuilder.cs
index 538accdfed..3ef39edb34 100644
--- a/src/Microsoft.AspNetCore.Blazor/RenderTree/RenderTreeDiffBuilder.cs
+++ b/src/Microsoft.AspNetCore.Blazor/RenderTree/RenderTreeDiffBuilder.cs
@@ -291,7 +291,7 @@ namespace Microsoft.AspNetCore.Blazor.RenderTree
             }
         }
 
-        private static int NextSiblingIndex(RenderTreeFrame frame, int frameIndex)
+        private static int NextSiblingIndex(in RenderTreeFrame frame, int frameIndex)
         {
             switch (frame.FrameType)
             {
diff --git a/src/Microsoft.AspNetCore.Blazor/Rendering/Renderer.cs b/src/Microsoft.AspNetCore.Blazor/Rendering/Renderer.cs
index a6c5431547..8107870561 100644
--- a/src/Microsoft.AspNetCore.Blazor/Rendering/Renderer.cs
+++ b/src/Microsoft.AspNetCore.Blazor/Rendering/Renderer.cs
@@ -62,7 +62,7 @@ namespace Microsoft.AspNetCore.Blazor.Rendering
         /// Updates the visible UI.
         /// </summary>
         /// <param name="renderBatch">The changes to the UI since the previous call.</param>
-        protected abstract void UpdateDisplay(RenderBatch renderBatch);
+        protected abstract void UpdateDisplay(in RenderBatch renderBatch);
 
         /// <summary>
         /// Notifies the specified component that an event has occurred.
diff --git a/test/Microsoft.AspNetCore.Blazor.Build.Test/RazorIntegrationTestBase.cs b/test/Microsoft.AspNetCore.Blazor.Build.Test/RazorIntegrationTestBase.cs
index 4c8c67cab6..fe9a6818fd 100644
--- a/test/Microsoft.AspNetCore.Blazor.Build.Test/RazorIntegrationTestBase.cs
+++ b/test/Microsoft.AspNetCore.Blazor.Build.Test/RazorIntegrationTestBase.cs
@@ -370,7 +370,7 @@ namespace Microsoft.AspNetCore.Blazor.Build.Test
             public void AttachComponent(IComponent component)
                 => AssignComponentId(component);
 
-            protected override void UpdateDisplay(RenderBatch renderBatch)
+            protected override void UpdateDisplay(in RenderBatch renderBatch)
             {
                 LatestBatchReferenceFrames = renderBatch.ReferenceFrames.ToArray();
             }
diff --git a/test/Microsoft.AspNetCore.Blazor.Test/RenderTreeBuilderTest.cs b/test/Microsoft.AspNetCore.Blazor.Test/RenderTreeBuilderTest.cs
index 0c827cb4bf..d7b362c175 100644
--- a/test/Microsoft.AspNetCore.Blazor.Test/RenderTreeBuilderTest.cs
+++ b/test/Microsoft.AspNetCore.Blazor.Test/RenderTreeBuilderTest.cs
@@ -1005,7 +1005,7 @@ namespace Microsoft.AspNetCore.Blazor.Test
             {
             }
 
-            protected override void UpdateDisplay(RenderBatch renderBatch)
+            protected override void UpdateDisplay(in RenderBatch renderBatch)
                 => throw new NotImplementedException();
         }
     }
diff --git a/test/Microsoft.AspNetCore.Blazor.Test/RenderTreeDiffBuilderTest.cs b/test/Microsoft.AspNetCore.Blazor.Test/RenderTreeDiffBuilderTest.cs
index f0aeb8f6cc..fa9a432348 100644
--- a/test/Microsoft.AspNetCore.Blazor.Test/RenderTreeDiffBuilderTest.cs
+++ b/test/Microsoft.AspNetCore.Blazor.Test/RenderTreeDiffBuilderTest.cs
@@ -1496,7 +1496,7 @@ namespace Microsoft.AspNetCore.Blazor.Test
             {
             }
 
-            protected override void UpdateDisplay(RenderBatch renderBatch)
+            protected override void UpdateDisplay(in RenderBatch renderBatch)
             {
             }
         }
diff --git a/test/Microsoft.AspNetCore.Blazor.Test/RendererTest.cs b/test/Microsoft.AspNetCore.Blazor.Test/RendererTest.cs
index 361971ae73..26f8d39f50 100644
--- a/test/Microsoft.AspNetCore.Blazor.Test/RendererTest.cs
+++ b/test/Microsoft.AspNetCore.Blazor.Test/RendererTest.cs
@@ -1080,7 +1080,7 @@ namespace Microsoft.AspNetCore.Blazor.Test
             public new int AssignComponentId(IComponent component)
                 => base.AssignComponentId(component);
 
-            protected override void UpdateDisplay(RenderBatch renderBatch)
+            protected override void UpdateDisplay(in RenderBatch renderBatch)
             {
             }
         }
diff --git a/test/shared/TestRenderer.cs b/test/shared/TestRenderer.cs
index 2817338a8c..269e7001a6 100644
--- a/test/shared/TestRenderer.cs
+++ b/test/shared/TestRenderer.cs
@@ -33,7 +33,7 @@ namespace Microsoft.AspNetCore.Blazor.Test.Helpers
         public T InstantiateComponent<T>() where T : IComponent
             => (T)InstantiateComponent(typeof(T));
 
-        protected override void UpdateDisplay(RenderBatch renderBatch)
+        protected override void UpdateDisplay(in RenderBatch renderBatch)
         {
             OnUpdateDisplay?.Invoke(renderBatch);