From dbba347f20d2d56e3a23e41f2c03caf1b7dd9e17 Mon Sep 17 00:00:00 2001
From: Pranav K <prkrishn@hotmail.com>
Date: Wed, 9 Dec 2020 13:06:05 -0800
Subject: [PATCH] Provide a better error message if a blazorwasm app references
 ASP.NET Core (#28493)

Fixes https://github.com/dotnet/aspnetcore/issues/28478
---
 .../WasmBuildIntegrationTest.cs               | 10 ++++++
 ....NET.Sdk.BlazorWebAssembly.Current.targets |  7 +++++
 .../RestoreBlazorWasmTestProjects.csproj      |  1 +
 .../Sdk/testassets/blazorwasm-fxref/App.razor |  1 +
 .../testassets/blazorwasm-fxref/Program.cs    | 11 +++++++
 .../blazorwasm-fxref/blazorwasm-fxref.csproj  | 31 +++++++++++++++++++
 6 files changed, 61 insertions(+)
 create mode 100644 src/Components/WebAssembly/Sdk/testassets/blazorwasm-fxref/App.razor
 create mode 100644 src/Components/WebAssembly/Sdk/testassets/blazorwasm-fxref/Program.cs
 create mode 100644 src/Components/WebAssembly/Sdk/testassets/blazorwasm-fxref/blazorwasm-fxref.csproj

diff --git a/src/Components/WebAssembly/Sdk/integrationtests/WasmBuildIntegrationTest.cs b/src/Components/WebAssembly/Sdk/integrationtests/WasmBuildIntegrationTest.cs
index 2a0e92fcc6..df9a036a84 100644
--- a/src/Components/WebAssembly/Sdk/integrationtests/WasmBuildIntegrationTest.cs
+++ b/src/Components/WebAssembly/Sdk/integrationtests/WasmBuildIntegrationTest.cs
@@ -335,6 +335,16 @@ namespace Microsoft.AspNetCore.Razor.Design.IntegrationTests
             Assert.BuildPassed(result);
         }
 
+        [Fact]
+        public async Task Build_WithAspNetCoreFrameworkReference_Fails()
+        {
+            // Arrange
+            using var project = ProjectDirectory.Create("blazorwasm-fxref");
+
+            var result = await MSBuildProcessManager.DotnetMSBuild(project);
+            Assert.BuildError(result, "BLAZORSDK1001");
+        }
+
         private static BootJsonData ReadBootJsonData(MSBuildResult result, string path)
         {
             return JsonSerializer.Deserialize<BootJsonData>(
diff --git a/src/Components/WebAssembly/Sdk/src/targets/Microsoft.NET.Sdk.BlazorWebAssembly.Current.targets b/src/Components/WebAssembly/Sdk/src/targets/Microsoft.NET.Sdk.BlazorWebAssembly.Current.targets
index e1e0a3c807..d8be7b59b1 100644
--- a/src/Components/WebAssembly/Sdk/src/targets/Microsoft.NET.Sdk.BlazorWebAssembly.Current.targets
+++ b/src/Components/WebAssembly/Sdk/src/targets/Microsoft.NET.Sdk.BlazorWebAssembly.Current.targets
@@ -631,6 +631,13 @@ Copyright (c) .NET Foundation. All rights reserved.
     </ItemGroup>
   </Target>
 
+  <Target Name="_FailIfReferencingAspNetCoreApp" BeforeTargets="ResolveRuntimePackAssets">
+    <Error
+      Code="BLAZORSDK1001"
+      Text="The project references the ASP.NET Core shared framework, which is not supported by Blazor WebAssembly apps. Remove the framework reference if directly referenced, or the package reference that adds the framework reference."
+      Condition="'@(FrameworkReference->WithMetadataValue('Identity', 'Microsoft.AspNetCore.App')->Count())' != '0'" />
+  </Target>
+
   <!--
     This is a hook to import a set of targets after the Blazor WebAssembly targets. By default this is unused.
   -->
diff --git a/src/Components/WebAssembly/Sdk/testassets/RestoreBlazorWasmTestProjects/RestoreBlazorWasmTestProjects.csproj b/src/Components/WebAssembly/Sdk/testassets/RestoreBlazorWasmTestProjects/RestoreBlazorWasmTestProjects.csproj
index 46b847139d..2af6c265d4 100644
--- a/src/Components/WebAssembly/Sdk/testassets/RestoreBlazorWasmTestProjects/RestoreBlazorWasmTestProjects.csproj
+++ b/src/Components/WebAssembly/Sdk/testassets/RestoreBlazorWasmTestProjects/RestoreBlazorWasmTestProjects.csproj
@@ -8,6 +8,7 @@
     <ProjectReference Include="..\blazorhosted-rid\blazorhosted-rid.csproj" />
     <ProjectReference Include="..\blazorwasm\blazorwasm.csproj" />
     <ProjectReference Include="..\blazorwasm-minimal\blazorwasm-minimal.csproj" />
+    <ProjectReference Include="..\blazorwasm-fxref\blazorwasm-fxref.csproj" />
   </ItemGroup>
 
 </Project>
diff --git a/src/Components/WebAssembly/Sdk/testassets/blazorwasm-fxref/App.razor b/src/Components/WebAssembly/Sdk/testassets/blazorwasm-fxref/App.razor
new file mode 100644
index 0000000000..0c55cf88d2
--- /dev/null
+++ b/src/Components/WebAssembly/Sdk/testassets/blazorwasm-fxref/App.razor
@@ -0,0 +1 @@
+Hello from App
\ No newline at end of file
diff --git a/src/Components/WebAssembly/Sdk/testassets/blazorwasm-fxref/Program.cs b/src/Components/WebAssembly/Sdk/testassets/blazorwasm-fxref/Program.cs
new file mode 100644
index 0000000000..3ebadb8b76
--- /dev/null
+++ b/src/Components/WebAssembly/Sdk/testassets/blazorwasm-fxref/Program.cs
@@ -0,0 +1,11 @@
+using System;
+
+namespace standalone
+{
+    public class Program
+    {
+        public static void Main(string[] args)
+        {
+        }
+    }
+}
diff --git a/src/Components/WebAssembly/Sdk/testassets/blazorwasm-fxref/blazorwasm-fxref.csproj b/src/Components/WebAssembly/Sdk/testassets/blazorwasm-fxref/blazorwasm-fxref.csproj
new file mode 100644
index 0000000000..b9708e7e15
--- /dev/null
+++ b/src/Components/WebAssembly/Sdk/testassets/blazorwasm-fxref/blazorwasm-fxref.csproj
@@ -0,0 +1,31 @@
+<Project Sdk="Microsoft.NET.Sdk.BlazorWebAssembly">
+
+  <PropertyGroup>
+    <TargetFramework>net5.0</TargetFramework>
+    <RuntimeIdentifier>browser-wasm</RuntimeIdentifier>
+    <RazorSdkDirectoryRoot>$(RazorSdkArtifactsDirectory)$(Configuration)\sdk-output\</RazorSdkDirectoryRoot>
+    <BlazorWebAssemblySdkDirectoryRoot>$(BlazorWebAssemblySdkArtifactsDirectory)$(Configuration)\sdk-output\</BlazorWebAssemblySdkDirectoryRoot>
+  </PropertyGroup>
+
+  <!-- Test Placeholder -->
+
+  <PropertyGroup Condition="'$(RunningAsTest)' == ''">
+    <!-- We don't want to run build server when not running as tests. -->
+    <UseRazorBuildServer>false</UseRazorBuildServer>
+  </PropertyGroup>
+
+  <PropertyGroup Condition="'$(BinariesRoot)'==''">
+    <!-- In test scenarios $(BinariesRoot) is defined in a generated Directory.Build.props file -->
+    <BinariesRoot>$(RepoRoot)artifacts\bin\Microsoft.AspNetCore.Razor.Test.MvcShim.ClassLib\$(Configuration)\netstandard2.0\</BinariesRoot>
+  </PropertyGroup>
+
+  <!-- DO NOT add addition references here. This is meant to simulate a non-MVC library -->
+  <ItemGroup Condition="'$(BinariesRoot)'!=''">
+    <Reference Include="$(BinariesRoot)\Microsoft.AspNetCore.Razor.Test.ComponentShim.dll"/>
+  </ItemGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Microsoft.AspNetCore.Authentication.JwtBearer" Version="5.0.0" />
+  </ItemGroup>
+
+</Project>