From 608da4c78b666fefcc7b6e1d74e6d3f7d25e0e25 Mon Sep 17 00:00:00 2001
From: Steve Sanderson <SteveSandersonMS@users.noreply.github.com>
Date: Mon, 19 Feb 2018 14:22:03 +0000
Subject: [PATCH] Specifying entrypoint: Add tests and other stylistic tweaks

---
 samples/StandaloneApp/Program.cs              | 10 +-----
 samples/StandaloneApp/StandaloneApp.csproj    |  1 -
 .../src/Boot.ts                               | 18 +++++++----
 .../src/Platform/Mono/MonoPlatform.ts         | 32 ++++++++-----------
 .../src/Platform/Platform.ts                  |  2 +-
 .../Core/FileSystem/ClientFileProvider.cs     | 25 +++++++++------
 .../Core/FileSystem/IndexHtmlFileProvider.cs  |  2 +-
 .../IndexHtmlFileProviderTest.cs              | 11 ++++---
 .../ReferencedAssemblyFileProviderTest.cs     |  2 +-
 .../Tests/StandaloneAppTest.cs                |  4 +--
 10 files changed, 53 insertions(+), 54 deletions(-)

diff --git a/samples/StandaloneApp/Program.cs b/samples/StandaloneApp/Program.cs
index c5a4bbba2d..1244342d11 100644
--- a/samples/StandaloneApp/Program.cs
+++ b/samples/StandaloneApp/Program.cs
@@ -5,15 +5,7 @@ using Microsoft.AspNetCore.Blazor.Browser.Rendering;
 
 namespace StandaloneApp
 {
-    public class ProgramX
-    {
-        public static void Main(string[] args)
-        {
-            new BrowserRenderer().AddComponent<Home>("app");
-        }
-    }
-
-    public class ProgramY
+    public class Program
     {
         public static void Main(string[] args)
         {
diff --git a/samples/StandaloneApp/StandaloneApp.csproj b/samples/StandaloneApp/StandaloneApp.csproj
index 2c16743b73..558911261e 100644
--- a/samples/StandaloneApp/StandaloneApp.csproj
+++ b/samples/StandaloneApp/StandaloneApp.csproj
@@ -6,7 +6,6 @@
     <!-- Local alternative to <RunArguments>blazor serve</RunArguments> -->
     <RunCommand>dotnet</RunCommand>
     <RunArguments>run --project ../../src/Microsoft.AspNetCore.Blazor.DevHost serve</RunArguments>
-    <StartupObject>StandaloneApp.ProgramY</StartupObject>
   </PropertyGroup>
 
   <ItemGroup>
diff --git a/src/Microsoft.AspNetCore.Blazor.Browser.JS/src/Boot.ts b/src/Microsoft.AspNetCore.Blazor.Browser.JS/src/Boot.ts
index 6a77d6a3dc..1c62684cc4 100644
--- a/src/Microsoft.AspNetCore.Blazor.Browser.JS/src/Boot.ts
+++ b/src/Microsoft.AspNetCore.Blazor.Browser.JS/src/Boot.ts
@@ -6,13 +6,9 @@ import './GlobalExports';
 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];
-  const entryPointDll = thisScriptElem.getAttribute('main');
-  if (!entryPointDll) {
-    throw new Error('Missing "main" attribute on Blazor script tag.');
-  }
-  // TODO:  should method be a required, non-empty field or just an optional *hint*?
-  const entryPointMethod = thisScriptElem.getAttribute('entry-point');
+  const thisScriptElem = (document.currentScript || allScriptElems[allScriptElems.length - 1]) as HTMLScriptElement;
+  const entryPointDll = getRequiredBootScriptAttribute(thisScriptElem, 'main');
+  const entryPointMethod = getRequiredBootScriptAttribute(thisScriptElem, 'entrypoint');
   const entryPointAssemblyName = getAssemblyNameFromUrl(entryPointDll);
   const referenceAssembliesCommaSeparated = thisScriptElem.getAttribute('references') || '';
   const referenceAssemblies = referenceAssembliesCommaSeparated
@@ -35,4 +31,12 @@ async function boot() {
   platform.callEntryPoint(entryPointAssemblyName, entryPointMethod, []);
 }
 
+function getRequiredBootScriptAttribute(elem: HTMLScriptElement, attributeName: string): string {
+  const result = elem.getAttribute(attributeName);
+  if (!result) {
+    throw new Error(`Missing "${attributeName}" attribute on Blazor script tag.`);
+  }
+  return result;
+}
+
 boot();
diff --git a/src/Microsoft.AspNetCore.Blazor.Browser.JS/src/Platform/Mono/MonoPlatform.ts b/src/Microsoft.AspNetCore.Blazor.Browser.JS/src/Platform/Mono/MonoPlatform.ts
index 6fa6ccdc7d..4def049f99 100644
--- a/src/Microsoft.AspNetCore.Blazor.Browser.JS/src/Platform/Mono/MonoPlatform.ts
+++ b/src/Microsoft.AspNetCore.Blazor.Browser.JS/src/Platform/Mono/MonoPlatform.ts
@@ -45,25 +45,21 @@ export const monoPlatform: Platform = {
     return methodHandle;
   },
 
-  callEntryPoint: function callEntryPoint(assemblyName: string, methodName: string | null, args: System_Object[]): void {
-    // TODO: There should be a proper way of running whatever counts as the entrypoint without
-    // having to specify what method it is, but I haven't found it. The code here assumes
-    // that the entry point is "<assemblyname>.Program.Main" (i.e., namespace == assembly name).
-    if (!methodName)
-        methodName = assemblyName + ".Program::Main";
+  callEntryPoint: function callEntryPoint(assemblyName: string, entrypointMethod: string, args: System_Object[]): void {
+    // Parse the entrypointMethod, which is of the form MyApp.MyNamespace.MyTypeName::MyMethodName
+    // Note that we don't support specifying a method overload, so it has to be unique
+    const entrypointSegments = entrypointMethod.split("::");
+    if (entrypointSegments.length != 2) {
+      throw new Error("malformed entry point method name; could not resolve class name and method name");
+    }
+    const typeFullName = entrypointSegments[0];
+    const methodName = entrypointSegments[1];
+    const lastDot = typeFullName.lastIndexOf('.');
+    const namespace = lastDot > -1 ? typeFullName.substring(0, lastDot) : '';
+    const typeShortName = lastDot > -1 ? typeFullName.substring(lastDot + 1) : typeFullName;
 
-    var classAndMethod = methodName.split("::");
-    if (classAndMethod.length != 2)
-        throw new Error("malformed entry point method name; could not resolve class name and method name");
-
-    methodName = classAndMethod[1];
-    const nsAndClass = classAndMethod[0];
-    const lastDot = nsAndClass.lastIndexOf(".");
-    // It's possible the entry point method has no namespace
-    const namespace = lastDot > -1 ? classAndMethod[0].substring(0, lastDot) : "";
-    const className = lastDot > -1 ? classAndMethod[0].substring(lastDot + 1) : classAndMethod[0];
-    const entryPointMethod = monoPlatform.findMethod(assemblyName, namespace, className, methodName);
-    monoPlatform.callMethod(entryPointMethod, null, args);
+    const entryPointMethodHandle = monoPlatform.findMethod(assemblyName, namespace, typeShortName, methodName);
+    monoPlatform.callMethod(entryPointMethodHandle, null, args);
   },
 
   callMethod: function callMethod(method: MethodHandle, target: System_Object, args: System_Object[]): System_Object {
diff --git a/src/Microsoft.AspNetCore.Blazor.Browser.JS/src/Platform/Platform.ts b/src/Microsoft.AspNetCore.Blazor.Browser.JS/src/Platform/Platform.ts
index 38cad75f7c..1e1272152e 100644
--- a/src/Microsoft.AspNetCore.Blazor.Browser.JS/src/Platform/Platform.ts
+++ b/src/Microsoft.AspNetCore.Blazor.Browser.JS/src/Platform/Platform.ts
@@ -1,7 +1,7 @@
 export interface Platform {
   start(loadAssemblyUrls: string[]): Promise<void>;
 
-  callEntryPoint(assemblyName: string, assemblyMethod: string | null, args: System_Object[]);
+  callEntryPoint(assemblyName: string, entrypointMethod: string, args: System_Object[]);
   findMethod(assemblyName: string, namespace: string, className: string, methodName: string): MethodHandle;
   callMethod(method: MethodHandle, target: System_Object | null, args: System_Object[]): System_Object;
 
diff --git a/src/Microsoft.AspNetCore.Blazor.Build/Core/FileSystem/ClientFileProvider.cs b/src/Microsoft.AspNetCore.Blazor.Build/Core/FileSystem/ClientFileProvider.cs
index 2f7d4a7117..8ff6e301e7 100644
--- a/src/Microsoft.AspNetCore.Blazor.Build/Core/FileSystem/ClientFileProvider.cs
+++ b/src/Microsoft.AspNetCore.Blazor.Build/Core/FileSystem/ClientFileProvider.cs
@@ -4,6 +4,7 @@
 using Microsoft.AspNetCore.Blazor.Internal.Common.FileProviders;
 using Microsoft.Extensions.FileProviders;
 using Mono.Cecil;
+using System;
 using System.Collections.Generic;
 using System.IO;
 
@@ -51,16 +52,8 @@ namespace Microsoft.AspNetCore.Blazor.Build.Core.FileSystem
                 {
                     var template = File.ReadAllText(path);
                     var assemblyName = Path.GetFileNameWithoutExtension(assemblyPath);
-                    var assemblyEntryPoint = string.Empty;
+                    var assemblyEntryPoint = GetAssemblyEntryPoint(assemblyPath);
                     var binFiles = frameworkFileProvider.GetDirectoryContents("/_bin");
-
-                    using (var asmDef = AssemblyDefinition.ReadAssembly(assemblyPath))
-                    {
-                        var ep = asmDef.EntryPoint;
-                        if (ep != null)
-                            assemblyEntryPoint = $"{ep.DeclaringType.FullName}::{ep.Name}";
-                    }
-
                     result = new IndexHtmlFileProvider(template, assemblyName, assemblyEntryPoint, binFiles);
                     return true;
                 }
@@ -69,5 +62,19 @@ namespace Microsoft.AspNetCore.Blazor.Build.Core.FileSystem
             result = null;
             return false;
         }
+
+        private static string GetAssemblyEntryPoint(string assemblyPath)
+        {
+            using (var assemblyDefinition = AssemblyDefinition.ReadAssembly(assemblyPath))
+            {
+                var entryPoint = assemblyDefinition.EntryPoint;
+                if (entryPoint == null)
+                {
+                    throw new ArgumentException($"The assembly at {assemblyPath} has no specified entry point.");
+                }
+
+                return $"{entryPoint.DeclaringType.FullName}::{entryPoint.Name}";
+            }
+        }
     }
 }
diff --git a/src/Microsoft.AspNetCore.Blazor.Build/Core/FileSystem/IndexHtmlFileProvider.cs b/src/Microsoft.AspNetCore.Blazor.Build/Core/FileSystem/IndexHtmlFileProvider.cs
index 7f9fb9aada..f9cc917462 100644
--- a/src/Microsoft.AspNetCore.Blazor.Build/Core/FileSystem/IndexHtmlFileProvider.cs
+++ b/src/Microsoft.AspNetCore.Blazor.Build/Core/FileSystem/IndexHtmlFileProvider.cs
@@ -149,7 +149,7 @@ namespace Microsoft.AspNetCore.Blazor.Build.Core.FileSystem
             attributesDict.Remove("type");
             attributesDict["src"] = "/_framework/blazor.js";
             attributesDict["main"] = assemblyNameWithExtension;
-            attributesDict["entry-point"] = assemblyEntryPoint;
+            attributesDict["entrypoint"] = assemblyEntryPoint;
             attributesDict["references"] = referencesAttribute;
 
             resultBuilder.Append("<script");
diff --git a/test/Microsoft.AspNetCore.Blazor.Build.Test/IndexHtmlFileProviderTest.cs b/test/Microsoft.AspNetCore.Blazor.Build.Test/IndexHtmlFileProviderTest.cs
index bfd0f8c55d..3d5965097d 100644
--- a/test/Microsoft.AspNetCore.Blazor.Build.Test/IndexHtmlFileProviderTest.cs
+++ b/test/Microsoft.AspNetCore.Blazor.Build.Test/IndexHtmlFileProviderTest.cs
@@ -18,7 +18,7 @@ namespace Microsoft.AspNetCore.Blazor.Server.Test
         {
             // Arrange
             var instance = new IndexHtmlFileProvider(
-                null, "fakeassembly", null, Enumerable.Empty<IFileInfo>());
+                null, "fakeassembly", "MyNamespace.MyType::MyMethod", Enumerable.Empty<IFileInfo>());
 
             // Act
             var file = instance.GetFileInfo("/index.html");
@@ -33,7 +33,7 @@ namespace Microsoft.AspNetCore.Blazor.Server.Test
             // Arrange
             var htmlTemplate = "test";
             var instance = new IndexHtmlFileProvider(
-                htmlTemplate, "fakeassembly", null, Enumerable.Empty<IFileInfo>());
+                htmlTemplate, "fakeassembly", "MyNamespace.MyType::MyMethod", Enumerable.Empty<IFileInfo>());
 
             // Act
             var file = instance.GetFileInfo("/index.html");
@@ -52,7 +52,7 @@ namespace Microsoft.AspNetCore.Blazor.Server.Test
             // Arrange
             var htmlTemplate = "test";
             var instance = new IndexHtmlFileProvider(
-                htmlTemplate, "fakeassembly", null, Enumerable.Empty<IFileInfo>());
+                htmlTemplate, "fakeassembly", "MyNamespace.MyType::MyMethod", Enumerable.Empty<IFileInfo>());
 
             // Act
             var directory = instance.GetDirectoryContents(string.Empty);
@@ -86,7 +86,7 @@ namespace Microsoft.AspNetCore.Blazor.Server.Test
                 new TestFileInfo("MyApp.ClassLib.dll"),
             };
             var instance = new IndexHtmlFileProvider(
-                htmlTemplate, "MyApp.Entrypoint", null, dependencies);
+                htmlTemplate, "MyApp.Entrypoint", "MyNamespace.MyType::MyMethod", dependencies);
 
             // Act
             var file = instance.GetFileInfo("/index.html");
@@ -103,6 +103,7 @@ namespace Microsoft.AspNetCore.Blazor.Server.Test
             Assert.False(scriptElem.HasChildNodes);
             Assert.Equal("/_framework/blazor.js", scriptElem.GetAttribute("src"));
             Assert.Equal("MyApp.Entrypoint.dll", scriptElem.GetAttribute("main"));
+            Assert.Equal("MyNamespace.MyType::MyMethod", scriptElem.GetAttribute("entrypoint"));
             Assert.Equal("System.Abc.dll,MyApp.ClassLib.dll", scriptElem.GetAttribute("references"));
             Assert.False(scriptElem.HasAttribute("type"));
             Assert.Equal(string.Empty, scriptElem.Attributes["custom1"].Value);
@@ -120,7 +121,7 @@ namespace Microsoft.AspNetCore.Blazor.Server.Test
                 new TestFileInfo("MyApp.ClassLib.dll"),
             };
             var instance = new IndexHtmlFileProvider(
-                htmlTemplate, "MyApp.Entrypoint", null, dependencies);
+                htmlTemplate, "MyApp.Entrypoint", "MyNamespace.MyType::MyMethod", dependencies);
 
             // Act
             var file = instance.GetFileInfo("/index.html");
diff --git a/test/Microsoft.AspNetCore.Blazor.Build.Test/ReferencedAssemblyFileProviderTest.cs b/test/Microsoft.AspNetCore.Blazor.Build.Test/ReferencedAssemblyFileProviderTest.cs
index 9c77e36c12..30e153b7e0 100644
--- a/test/Microsoft.AspNetCore.Blazor.Build.Test/ReferencedAssemblyFileProviderTest.cs
+++ b/test/Microsoft.AspNetCore.Blazor.Build.Test/ReferencedAssemblyFileProviderTest.cs
@@ -46,7 +46,7 @@ namespace Microsoft.AspNetCore.Blazor.Server.Test
         public void FindsReferencedAssemblyGraphRealistic()
         {
             // Arrange
-            var standaloneAppAssembly = typeof(StandaloneApp.ProgramY).Assembly;
+            var standaloneAppAssembly = typeof(StandaloneApp.Program).Assembly;
             var provider = new ReferencedAssemblyFileProvider(
                 standaloneAppAssembly.GetName().Name,
                 new ReferencedAssemblyResolver(
diff --git a/test/Microsoft.AspNetCore.Blazor.E2ETest/Tests/StandaloneAppTest.cs b/test/Microsoft.AspNetCore.Blazor.E2ETest/Tests/StandaloneAppTest.cs
index c9cd8cbb04..bfcac18d6e 100644
--- a/test/Microsoft.AspNetCore.Blazor.E2ETest/Tests/StandaloneAppTest.cs
+++ b/test/Microsoft.AspNetCore.Blazor.E2ETest/Tests/StandaloneAppTest.cs
@@ -11,9 +11,9 @@ using Xunit;
 namespace Microsoft.AspNetCore.Blazor.E2ETest.Tests
 {
     public class StandaloneAppTest
-        : ServerTestBase<DevHostServerFixture<StandaloneApp.ProgramY>>
+        : ServerTestBase<DevHostServerFixture<StandaloneApp.Program>>
     {
-        public StandaloneAppTest(BrowserFixture browserFixture, DevHostServerFixture<StandaloneApp.ProgramY> serverFixture)
+        public StandaloneAppTest(BrowserFixture browserFixture, DevHostServerFixture<StandaloneApp.Program> serverFixture)
             : base(browserFixture, serverFixture)
         {
             Navigate("/", noReload: true);