Move JSX Transformer to separate class

Author: Daniel15

src/React.Sample.Cassette/React.Sample.Cassette.csproj

@@ -211,7 +211,7 @@
       </FlavorProperties>
     </VisualStudio>
   </ProjectExtensions>
-	<Target Name="Bundle" AfterTargets="Build">
+	<Target Name="Bundle" AfterTargets="Build" Condition="'$(Configuration)' == 'Release'">
 		<Exec Command="&quot;$(msbuildtoolspath)\msbuild.exe&quot; $(ProjectDirectory)cassette.targets /p:OutputPath=$(OutputPath) /t:Bundle /nr:false" />
 	</Target>
   <!-- To modify your build process, add your task inside one of the targets below and uncomment it. 

src/React.Tests/Core/JsxTransformerTests.cs

@@ -0,0 +1,53 @@
+/*
+ *  Copyright (c) 2014, Facebook, Inc.
+ *  All rights reserved.
+ *
+ *  This source code is licensed under the BSD-style license found in the
+ *  LICENSE file in the root directory of this source tree. An additional grant 
+ *  of patent rights can be found in the PATENTS file in the same directory.
+ */
+
+using Moq;
+using Xunit;
+
+namespace React.Tests.Core
+{
+	public class JsxTransformerTests
+	{
+		[Fact]
+		public void ShouldNotTransformJsxIfNoAnnotationPresent()
+		{
+			var environment = new Mock<IReactEnvironment>();
+			var cache = new Mock<ICache>();
+			var fileSystem = new Mock<IFileSystem>();
+			var jsxTransformer = new JsxTransformer(
+				environment.Object, 
+				cache.Object, 
+				fileSystem.Object
+			);
+			const string input = "<div>Hello World</div>";
+
+			var output = jsxTransformer.TransformJsx(input);
+			Assert.Equal(input, output);
+		}
+
+		[Fact]
+		public void ShouldTransformJsxIfAnnotationPresent()
+		{
+			var environment = new Mock<IReactEnvironment>();
+			var cache = new Mock<ICache>();
+			var fileSystem = new Mock<IFileSystem>();
+			var jsxTransformer = new JsxTransformer(
+				environment.Object,
+				cache.Object,
+				fileSystem.Object
+			);
+			const string input = "/** @jsx React.DOM */ <div>Hello World</div>";
+			jsxTransformer.TransformJsx(input);
+
+			environment.Verify(x => x.ExecuteWithLargerStackIfRequired<string>(
+				@"global.JSXTransformer.transform(""/** @jsx React.DOM */ <div>Hello World</div>"").code"
+			));
+		}
+	}
+}

src/React.Tests/Core/ReactEnvironmentTest.cs

@@ -16,31 +16,6 @@ namespace React.Tests.Core
 {
 	public class ReactEnvironmentTest
 	{
-		[Fact]
-		public void ShouldNotTransformJsxIfNoAnnotationPresent()
-		{
-			var mocks = new Mocks();
-			var environment = mocks.CreateReactEnvironment();
-			var input = "<div>Hello World</div>";
-
-			var output = environment.TransformJsx(input);
-			Assert.Equal(input, output);
-		}
-
-		[Fact]
-		public void ShouldTransformJsxIfAnnotationPresent()
-		{
-			var mocks = new Mocks();
-			var environment = mocks.CreateReactEnvironment();
-
-			const string input = "/** @jsx React.DOM */ <div>Hello World</div>";
-			environment.TransformJsx(input);
-
-			mocks.Engine.Verify(x => x.Evaluate<string>(
-				@"global.JSXTransformer.transform(""/** @jsx React.DOM */ <div>Hello World</div>"").code"
-			));
-		}
-
 		[Fact]
 		public void ExecuteWithLargerStackIfRequiredWithNoNewThread()
 		{

src/React.Tests/React.Tests.csproj

@@ -20,7 +20,7 @@
     <DefineConstants>DEBUG;TRACE</DefineConstants>
     <ErrorReport>prompt</ErrorReport>
     <WarningLevel>4</WarningLevel>
-    <TreatWarningsAsErrors>true</TreatWarningsAsErrors>
+    <TreatWarningsAsErrors>false</TreatWarningsAsErrors>
     <NoWarn>1607</NoWarn>
   </PropertyGroup>
   <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
@@ -67,6 +67,7 @@
       <Link>Properties\SharedAssemblyVersionInfo.cs</Link>
     </Compile>
     <Compile Include="Core\JavaScriptEngineFactoryTest.cs" />
+    <Compile Include="Core\JsxTransformerTests.cs" />
     <Compile Include="Core\ReactComponentTest.cs" />
     <Compile Include="Properties\AssemblyInfo.cs" />
     <Compile Include="Core\ReactEnvironmentTest.cs" />

src/React/IJsxTransformer.cs

@@ -0,0 +1,32 @@
+/*
+ *  Copyright (c) 2014, Facebook, Inc.
+ *  All rights reserved.
+ *
+ *  This source code is licensed under the BSD-style license found in the
+ *  LICENSE file in the root directory of this source tree. An additional grant 
+ *  of patent rights can be found in the PATENTS file in the same directory.
+ */
+
+namespace React
+{
+	/// <summary>
+	/// Handles compiling JSX to JavaScript.
+	/// </summary>
+	public interface IJsxTransformer
+	{
+		/// <summary>
+		/// Loads a JSX file. Results of the JSX to JavaScript transformation are cached.
+		/// </summary>
+		/// <param name="filename">Name of the file to load</param>
+		/// <returns>File contents</returns>
+		string LoadJsxFile(string filename);
+
+		/// <summary>
+		/// Transforms JSX into regular JavaScript. The result is not cached. Use 
+		/// <see cref="JsxTransformer.LoadJsxFile"/> if loading from a file since this will cache the result.
+		/// </summary>
+		/// <param name="input">JSX</param>
+		/// <returns>JavaScript</returns>
+		string TransformJsx(string input);
+	}
+}

src/React/IReactEnvironment.cs

@@ -29,6 +29,18 @@ public interface IReactEnvironment
 		/// <returns>Result of the JavaScript code</returns>
 		T Execute<T>(string code);
 
+		/// <summary>
+		/// Attempts to execute the provided JavaScript code using the current engine. If an 
+		/// exception is thrown, retries the execution using a new thread (and hence a new engine)
+		/// with a larger maximum stack size.
+		/// This is required because JSXTransformer uses a huge stack which ends up being larger 
+		/// than what ASP.NET allows by default (256 KB).
+		/// </summary>
+		/// <typeparam name="T">Type to return from JavaScript call</typeparam>
+		/// <param name="code">JavaScript code to execute</param>
+		/// <returns>Result returned from JavaScript code</returns>
+		T ExecuteWithLargerStackIfRequired<T>(string code);
+
 		/// <summary>
 		/// Determines if the specified variable exists in the JavaScript engine
 		/// </summary>

src/React/JsxTransformer.cs

@@ -0,0 +1,104 @@
+/*
+ *  Copyright (c) 2014, Facebook, Inc.
+ *  All rights reserved.
+ *
+ *  This source code is licensed under the BSD-style license found in the
+ *  LICENSE file in the root directory of this source tree. An additional grant 
+ *  of patent rights can be found in the PATENTS file in the same directory.
+ */
+
+using System;
+using System.Diagnostics;
+using Newtonsoft.Json;
+using React.Exceptions;
+
+namespace React
+{
+	/// <summary>
+	/// Handles compiling JSX to JavaScript.
+	/// </summary>
+	public class JsxTransformer : IJsxTransformer
+	{
+		/// <summary>
+		/// Cache key for JSX to JavaScript compilation
+		/// </summary>
+		private const string JSX_CACHE_KEY = "JSX_{0}";
+
+		/// <summary>
+		/// Environment this JSX Transformer has been created in
+		/// </summary>
+		private readonly IReactEnvironment _environment;
+		/// <summary>
+		/// Cache used for storing compiled JSX
+		/// </summary>
+		private readonly ICache _cache;
+		/// <summary>
+		/// File system wrapper
+		/// </summary>
+		private readonly IFileSystem _fileSystem;
+
+		/// <summary>
+		/// Initializes a new instance of the <see cref="JsxTransformer"/> class.
+		/// </summary>
+		/// <param name="environment">The ReactJS.NET environment</param>
+		/// <param name="cache">The cache to use for JSX compilation</param>
+		/// <param name="fileSystem">File system wrapper</param>
+		public JsxTransformer(IReactEnvironment environment, ICache cache, IFileSystem fileSystem)
+		{
+			_environment = environment;
+			_cache = cache;
+			_fileSystem = fileSystem;
+		}
+
+		/// <summary>
+		/// Loads a JSX file. Results of the JSX to JavaScript transformation are cached.
+		/// </summary>
+		/// <param name="filename">Name of the file to load</param>
+		/// <returns>File contents</returns>
+		public string LoadJsxFile(string filename)
+		{
+			var fullPath = _fileSystem.MapPath(filename);
+
+			return _cache.GetOrInsert(
+				key: string.Format(JSX_CACHE_KEY, filename),
+				slidingExpiration: TimeSpan.FromMinutes(30),
+				cacheDependencyFiles: new[] { fullPath },
+				getData: () =>
+				{
+					Trace.WriteLine(string.Format("Parsing JSX from {0}", filename));
+					var contents = _fileSystem.ReadAsString(filename);
+					return TransformJsx(contents);
+				}
+			);
+		}
+
+		/// <summary>
+		/// Transforms JSX into regular JavaScript. The result is not cached. Use 
+		/// <see cref="LoadJsxFile"/> if loading from a file since this will cache the result.
+		/// </summary>
+		/// <param name="input">JSX</param>
+		/// <returns>JavaScript</returns>
+		public string TransformJsx(string input)
+		{
+			// Just return directly if there's no JSX annotation
+			if (!input.Contains("@jsx"))
+			{
+				return input;
+			}
+
+			try
+			{
+				var encodedInput = JsonConvert.SerializeObject(input);
+				var output = _environment.ExecuteWithLargerStackIfRequired<string>(string.Format(
+					"global.JSXTransformer.transform({0}).code",
+					encodedInput
+				));
+				return output;
+			}
+			catch (Exception ex)
+			{
+				throw new JsxException(ex.Message, ex);
+			}
+		}
+	}
+}

src/React/React.csproj

@@ -83,12 +83,14 @@
     <Compile Include="ICache.cs" />
     <Compile Include="IFileSystem.cs" />
     <Compile Include="IJavaScriptEngineFactory.cs" />
+    <Compile Include="IJsxTransformer.cs" />
     <Compile Include="Initializer.cs" />
     <Compile Include="IReactComponent.cs" />
     <Compile Include="IReactEnvironment.cs" />
     <Compile Include="IReactSiteConfiguration.cs" />
     <Compile Include="Exceptions\JsxException.cs" />
     <Compile Include="JavaScriptEngineFactory.cs" />
+    <Compile Include="JsxTransformer.cs" />
     <Compile Include="NullCache.cs" />
     <Compile Include="Properties\AssemblyInfo.cs" />
     <Compile Include="ReactComponent.cs" />