From cf237707f9396e420cc99270f20bdd208bbf84d3 Mon Sep 17 00:00:00 2001
From: Steve Sanderson <SteveSandersonMS@users.noreply.github.com>
Date: Tue, 20 Mar 2018 21:36:12 +0000
Subject: [PATCH] Log info message if IL linking is disabled. Fixes #302

---
 .../src/Boot.ts                                 |  5 +++++
 .../Cli/Commands/BuildIndexHtmlCommand.cs       |  5 +++++
 .../Core/IndexHtmlWriter.cs                     | 17 +++++++++++++++--
 .../targets/Blazor.MonoRuntime.targets          | 10 +++++++---
 .../IndexHtmlWriterTest.cs                      |  6 ++++--
 5 files changed, 36 insertions(+), 7 deletions(-)

diff --git a/src/Microsoft.AspNetCore.Blazor.Browser.JS/src/Boot.ts b/src/Microsoft.AspNetCore.Blazor.Browser.JS/src/Boot.ts
index 28d395decc..065c711523 100644
--- a/src/Microsoft.AspNetCore.Blazor.Browser.JS/src/Boot.ts
+++ b/src/Microsoft.AspNetCore.Blazor.Browser.JS/src/Boot.ts
@@ -9,6 +9,7 @@ async function boot() {
   // Read startup config from the <script> element that's importing this file
   const allScriptElems = document.getElementsByTagName('script');
   const thisScriptElem = (document.currentScript || allScriptElems[allScriptElems.length - 1]) as HTMLScriptElement;
+  const isLinkerEnabled = thisScriptElem.getAttribute('linker-enabled') === 'true';
   const entryPointDll = getRequiredBootScriptAttribute(thisScriptElem, 'main');
   const entryPointMethod = getRequiredBootScriptAttribute(thisScriptElem, 'entrypoint');
   const entryPointAssemblyName = getAssemblyNameFromUrl(entryPointDll);
@@ -18,6 +19,10 @@ async function boot() {
     .map(s => s.trim())
     .filter(s => !!s);
 
+  if (!isLinkerEnabled) {
+    console.info('Blazor is running in dev mode without IL stripping. To make the bundle size significantly smaller, publish the application or see https://go.microsoft.com/fwlink/?linkid=870414');
+  }
+
   // Determine the URLs of the assemblies we want to load
   const loadAssemblyUrls = [entryPointDll]
     .concat(referenceAssemblies)
diff --git a/src/Microsoft.AspNetCore.Blazor.Build/Cli/Commands/BuildIndexHtmlCommand.cs b/src/Microsoft.AspNetCore.Blazor.Build/Cli/Commands/BuildIndexHtmlCommand.cs
index d689c59ffb..5f160d64f9 100644
--- a/src/Microsoft.AspNetCore.Blazor.Build/Cli/Commands/BuildIndexHtmlCommand.cs
+++ b/src/Microsoft.AspNetCore.Blazor.Build/Cli/Commands/BuildIndexHtmlCommand.cs
@@ -33,6 +33,10 @@ namespace Microsoft.AspNetCore.Blazor.Build.Cli.Commands
             var mainAssemblyPath = command.Argument("assembly",
                 "Path to the assembly containing the entry point of the application.");
 
+            var linkerEnabledFlag = command.Option("--linker-enabled",
+                "If set, specifies that the application is being built with linking enabled.",
+                CommandOptionType.NoValue);
+
             command.OnExecute(() =>
             {
                 if (string.IsNullOrEmpty(mainAssemblyPath.Value) ||
@@ -50,6 +54,7 @@ namespace Microsoft.AspNetCore.Blazor.Build.Cli.Commands
                         references.Values.ToArray(),
                         jsReferences.Values.ToArray(),
                         cssReferences.Values.ToArray(),
+                        linkerEnabledFlag.HasValue(),
                         outputPath.Value());
                     return 0;
                 }
diff --git a/src/Microsoft.AspNetCore.Blazor.Build/Core/IndexHtmlWriter.cs b/src/Microsoft.AspNetCore.Blazor.Build/Core/IndexHtmlWriter.cs
index a9e022439f..d8c7bf9c74 100644
--- a/src/Microsoft.AspNetCore.Blazor.Build/Core/IndexHtmlWriter.cs
+++ b/src/Microsoft.AspNetCore.Blazor.Build/Core/IndexHtmlWriter.cs
@@ -21,6 +21,7 @@ namespace Microsoft.AspNetCore.Blazor.Build
             IEnumerable<string> assemblyReferences,
             IEnumerable<string> jsReferences,
             IEnumerable<string> cssReferences,
+            bool linkerEnabled,
             string outputPath)
         {
             var template = GetTemplate(path);
@@ -30,7 +31,7 @@ namespace Microsoft.AspNetCore.Blazor.Build
             }
             var assemblyName = Path.GetFileNameWithoutExtension(assemblyPath);
             var entryPoint = GetAssemblyEntryPoint(assemblyPath);
-            var updatedContent = GetIndexHtmlContents(template, assemblyName, entryPoint, assemblyReferences, jsReferences, cssReferences);
+            var updatedContent = GetIndexHtmlContents(template, assemblyName, entryPoint, assemblyReferences, jsReferences, cssReferences, linkerEnabled);
             var normalizedOutputPath = Normalize(outputPath);
             Console.WriteLine("Writing index to: " + normalizedOutputPath);
             File.WriteAllText(normalizedOutputPath, updatedContent);
@@ -101,7 +102,8 @@ namespace Microsoft.AspNetCore.Blazor.Build
             string assemblyEntryPoint,
             IEnumerable<string> assemblyReferences,
             IEnumerable<string> jsReferences,
-            IEnumerable<string> cssReferences)
+            IEnumerable<string> cssReferences,
+            bool linkerEnabled)
         {
             var resultBuilder = new StringBuilder();
 
@@ -141,6 +143,7 @@ namespace Microsoft.AspNetCore.Blazor.Build
                                     assemblyName,
                                     assemblyEntryPoint,
                                     assemblyReferences,
+                                    linkerEnabled,
                                     tag.Attributes);
 
                                 // Emit tags to reference any specified JS/CSS files
@@ -198,6 +201,7 @@ namespace Microsoft.AspNetCore.Blazor.Build
             string assemblyName,
             string assemblyEntryPoint,
             IEnumerable<string> binFiles,
+            bool linkerEnabled,
             List<KeyValuePair<string, string>> attributes)
         {
             var assemblyNameWithExtension = $"{assemblyName}.dll";
@@ -211,6 +215,15 @@ namespace Microsoft.AspNetCore.Blazor.Build
             attributesDict["entrypoint"] = assemblyEntryPoint;
             attributesDict["references"] = referencesAttribute;
 
+            if (linkerEnabled)
+            {
+                attributesDict["linker-enabled"] = "true";
+            }
+            else
+            {
+                attributesDict.Remove("linker-enabled");
+            }
+
             resultBuilder.Append("<script");
             foreach (var attributePair in attributesDict)
             {
diff --git a/src/Microsoft.AspNetCore.Blazor.Build/targets/Blazor.MonoRuntime.targets b/src/Microsoft.AspNetCore.Blazor.Build/targets/Blazor.MonoRuntime.targets
index 7f140c6125..ad8453459a 100644
--- a/src/Microsoft.AspNetCore.Blazor.Build/targets/Blazor.MonoRuntime.targets
+++ b/src/Microsoft.AspNetCore.Blazor.Build/targets/Blazor.MonoRuntime.targets
@@ -260,8 +260,8 @@
       <_BlazorCommonInput Include="@(IntermediateAssembly)" />
       <_BlazorCommonInput Include="@(_BlazorDependencyInput)" />
       <_BlazorCommonInput Include="$(_BlazorShouldLinkApplicationAssemblies)" />
-      <_BlazorLinkingOption Condition="_BlazorShouldLinkApplicationAssemblies == ''" Include="false" />
-      <_BlazorLinkingOption Condition="_BlazorShouldLinkApplicationAssemblies != ''" Include="true" />
+      <_BlazorLinkingOption Condition="'$(_BlazorShouldLinkApplicationAssemblies)' == ''" Include="false" />
+      <_BlazorLinkingOption Condition="'$(_BlazorShouldLinkApplicationAssemblies)' != ''" Include="true" />
     </ItemGroup>
 
     <Hash ItemsToHash="@(_BlazorCommonInput)">
@@ -570,6 +570,7 @@
       <BlazorIndexHtmlInput Include="@(BlazorItemOutput->WithMetadataValue('Type','Assembly')->'%(FullPath)')" />
       <BlazorIndexHtmlInput Include="@(BlazorPackageJsRef->'%(FullPath)')" />
       <BlazorIndexHtmlInput Include="@(BlazorPackageCssRef->'%(FullPath)')" />
+      <BlazorIndexHtmlInput Include="@(_BlazorLinkingOption)" />
     </ItemGroup>
 
     <WriteLinesToFile
@@ -594,8 +595,11 @@
       <_JsReferences Include="@(BlazorPackageJsRef->'_content/%(SourcePackage)/%(RecursiveDir)%(FileName)%(Extension)')" />
       <_CssReferences Include="@(BlazorPackageCssRef->'_content/%(SourcePackage)/%(RecursiveDir)%(FileName)%(Extension)')" />
     </ItemGroup>
+    <PropertyGroup>
+      <_LinkerEnabledFlag Condition="'$(_BlazorShouldLinkApplicationAssemblies)' != ''">--linker-enabled</_LinkerEnabledFlag>
+    </PropertyGroup>
 
-    <Exec Command="$(BlazorBuildExe) build @(IntermediateAssembly) --html-page &quot;$(BlazorIndexHtml)&quot; @(_AppReferences->'--reference &quot;%(Identity)&quot;', ' ') @(_JsReferences->'--js &quot;%(Identity)&quot;', ' ') @(_CssReferences->'--css &quot;%(Identity)&quot;', ' ') --output &quot;$(BlazorIndexHtmlOutputPath)&quot;" />
+    <Exec Command="$(BlazorBuildExe) build @(IntermediateAssembly) --html-page &quot;$(BlazorIndexHtml)&quot; @(_AppReferences->'--reference &quot;%(Identity)&quot;', ' ') @(_JsReferences->'--js &quot;%(Identity)&quot;', ' ') @(_CssReferences->'--css &quot;%(Identity)&quot;', ' ') $(_LinkerEnabledFlag) --output &quot;$(BlazorIndexHtmlOutputPath)&quot;" />
 
     <ItemGroup Condition="Exists('$(BlazorIndexHtmlOutputPath)')">
       <_BlazorIndex Include="$(BlazorIndexHtmlOutputPath)" />
diff --git a/test/Microsoft.AspNetCore.Blazor.Build.Test/IndexHtmlWriterTest.cs b/test/Microsoft.AspNetCore.Blazor.Build.Test/IndexHtmlWriterTest.cs
index 8442204332..6b5bdae3a1 100644
--- a/test/Microsoft.AspNetCore.Blazor.Build.Test/IndexHtmlWriterTest.cs
+++ b/test/Microsoft.AspNetCore.Blazor.Build.Test/IndexHtmlWriterTest.cs
@@ -35,7 +35,8 @@ namespace Microsoft.AspNetCore.Blazor.Build.Test
                 "MyNamespace.MyType::MyMethod",
                 assemblyReferences,
                 jsReferences,
-                cssReferences);
+                cssReferences,
+                linkerEnabled: true);
 
             // Act & Assert: Start and end is not modified (including formatting)
             Assert.StartsWith(htmlTemplatePrefix, instance);
@@ -55,6 +56,7 @@ namespace Microsoft.AspNetCore.Blazor.Build.Test
             Assert.False(scriptElem.HasAttribute("type"));
             Assert.Equal(string.Empty, scriptElem.Attributes["custom1"].Value);
             Assert.Equal("value", scriptElem.Attributes["custom2"].Value);
+            Assert.Equal("true", scriptElem.Attributes["linker-enabled"].Value);
 
             // Assert: Also contains script tags referencing JS files
             Assert.Equal(
@@ -77,7 +79,7 @@ namespace Microsoft.AspNetCore.Blazor.Build.Test
             var cssReferences = new string[] { "my/styles.css" };
 
             var content = IndexHtmlWriter.GetIndexHtmlContents(
-                htmlTemplate, "MyApp.Entrypoint", "MyNamespace.MyType::MyMethod", assemblyReferences, jsReferences, cssReferences);
+                htmlTemplate, "MyApp.Entrypoint", "MyNamespace.MyType::MyMethod", assemblyReferences, jsReferences, cssReferences, linkerEnabled: true);
 
             // Assert
             Assert.Equal(htmlTemplate, content);