Add ability to return a source map from JsxTransformer.

Author: Daniel15

src/React/IJsxTransformer.cs

@@ -18,7 +18,7 @@ public interface IJsxTransformer
 		/// Transforms a JSX file. Results of the JSX to JavaScript transformation are cached.
 		/// </summary>
 		/// <param name="filename">Name of the file to load</param>
-		/// <param name="useHarmony"><c>true</c> if support for es6 syntax should be rewritten.</param>
+		/// <param name="useHarmony"><c>true</c> if support for ES6 syntax should be enabled</param>
 		/// <returns>JavaScript</returns>
 		string TransformJsxFile(string filename, bool? useHarmony = null);
 
@@ -27,16 +27,25 @@ public interface IJsxTransformer
 		/// <see cref="TransformJsxFile"/> if loading from a file since this will cache the result.
 		/// </summary>
 		/// <param name="input">JSX</param>
-		/// <param name="useHarmony"><c>true</c> if support for es6 syntax should be rewritten.</param>
+		/// <param name="useHarmony"><c>true</c> if support for ES6 syntax should be enabled</param>
 		/// <returns>JavaScript</returns>
 		string TransformJsx(string input, bool? useHarmony = null);
+		
+		/// <summary>
+		/// Transforms JSX to regular JavaScript and also returns a source map to map the compiled
+		/// source to the original version. The result is not cached.
+		/// </summary>
+		/// <param name="input">JSX</param>
+		/// <param name="useHarmony"><c>true</c> if support for ES6 syntax should be enabled</param>
+		/// <returns>JavaScript and source map</returns>
+		JavaScriptWithSourceMap TransformJsxWithSourceMap(string input, bool? useHarmony);
 
 		/// <summary>
 		/// Transforms a JSX file to JavaScript, and saves the result into a ".generated.js" file 
 		/// alongside the original file.
 		/// </summary>
 		/// <param name="filename">Name of the file to load</param>
-		/// <param name="useHarmony"><c>true</c> if support for es6 syntax should be rewritten.</param>
+		/// <param name="useHarmony"><c>true</c> if support for ES6 syntax should be enabled</param>
 		/// <returns>File contents</returns>
 		string TransformAndSaveJsxFile(string filename, bool? useHarmony = null);
 

src/React/JavaScriptWithSourceMap.cs

@@ -0,0 +1,31 @@
+/*
+ *  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;
+
+namespace React
+{
+	/// <summary>
+	/// Represents the result of a JSX to JavaScript transformation along with its
+	/// corresponding source map.
+	/// </summary>
+	[Serializable]
+	public class JavaScriptWithSourceMap
+	{
+		/// <summary>
+		/// The transformed result
+		/// </summary>
+		public string Code { get; set; }
+
+		/// <summary>
+		/// The source map for this code
+		/// </summary>
+		public SourceMap SourceMap { get; set; }
+	}
+}

src/React/JsxTransformer.cs

@@ -147,7 +147,7 @@ public string TransformJsx(string input, bool? useHarmony = null)
 				var output = _environment.ExecuteWithLargerStackIfRequired<string>(
 					"ReactNET_transform",
 					input,
-					useHarmony.HasValue ? useHarmony.Value : _config.UseHarmony
+					useHarmony ?? _config.UseHarmony
 				);
 				return output;
 			}
@@ -157,6 +157,30 @@ public string TransformJsx(string input, bool? useHarmony = null)
 			}
 		}
 
+		/// <summary>
+		/// Transforms JSX to regular JavaScript and also returns a source map to map the compiled
+		/// source to the original version. The result is not cached.
+		/// </summary>
+		/// <param name="input">JSX</param>
+		/// <param name="useHarmony"><c>true</c> if support for ES6 syntax should be enabled</param>
+		/// <returns>JavaScript and source map</returns>
+		public JavaScriptWithSourceMap TransformJsxWithSourceMap(string input, bool? useHarmony)
+		{
+			EnsureJsxTransformerSupported();
+			try
+			{
+				return _environment.ExecuteWithLargerStackIfRequired<JavaScriptWithSourceMap>(
+					"ReactNET_transform_sourcemap",
+					input,
+					useHarmony ?? _config.UseHarmony
+				);
+			}
+			catch (Exception ex)
+			{
+				throw new JsxException(ex.Message, ex);
+			}
+		}
+
 		/// <summary>
 		/// Gets the header prepended to JSX transformed files. Contains a hash that is used to 
 		/// validate the cache.

src/React/React.csproj

@@ -85,6 +85,8 @@
     <Compile Include="AssemblyRegistration.cs" />
     <Compile Include="Exceptions\ReactScriptLoadException.cs" />
     <Compile Include="Exceptions\ReactServerRenderingException.cs" />
+    <Compile Include="JavaScriptWithSourceMap.cs" />
+    <Compile Include="SourceMap.cs" />
     <Compile Include="SystemEnvironmentUtils.cs" />
     <Compile Include="Exceptions\JsxUnsupportedEngineException.cs" />
     <Compile Include="Exceptions\ReactConfigurationException.cs" />

src/React/ReactEnvironment.cs

@@ -14,6 +14,8 @@
 using System.Text;
 using System.Threading;
 using JavaScriptEngineSwitcher.Core;
+using JavaScriptEngineSwitcher.Core.Helpers;
+using Newtonsoft.Json;
 using React.Exceptions;
 
 namespace React
@@ -231,7 +233,26 @@ public T Execute<T>(string function, params object[] args)
 		{
 			try
 			{
-				return Engine.CallFunction<T>(function, args);
+				if (ValidationHelpers.IsSupportedType(typeof (T)))
+				{
+					// Type is supported directly (ie. a scalar type like string/int/bool)
+					// Just execute the function directly.
+					return Engine.CallFunction<T>(function, args);
+				}
+				// The type is not a scalar type. Assume the function will return its result as
+				// JSON.
+				var resultJson = Engine.CallFunction<string>(function, args);
+				try
+				{
+					return JsonConvert.DeserializeObject<T>(resultJson);
+				}
+				catch (JsonReaderException ex)
+				{
+					throw new ReactException(string.Format(
+						"{0} did not return valid JSON: {1}.\n\n{2}",
+						function, ex.Message, resultJson
+					));
+				}
 			}
 			catch (JsRuntimeException ex)
 			{

src/React/Resources/shims.js

@@ -25,4 +25,26 @@ function ReactNET_transform(input, harmony) {
 	} catch (ex) {
 		throw new Error(ex.message + " (at line " + ex.lineNumber + " column " + ex.column + ")");
 	}
+}
+
+function ReactNET_transform_sourcemap(input, harmony) {
+	try {
+		var result = global.JSXTransformer.transform(input, {
+			harmony: !!harmony,
+			sourceMap: true
+		});
+		if (!result.sourceMap) {
+			return JSON.stringify({
+				code: result.code,
+				sourceMap: null
+			});
+		}
+
+		return JSON.stringify({
+			code: result.code,
+			sourceMap: result.sourceMap.toJSON()
+		});
+	} catch (ex) {
+		throw new Error(ex.message + " (at line " + ex.lineNumber + " column " + ex.column + ")");
+	}
 }

src/React/SourceMap.cs

@@ -0,0 +1,61 @@
+/*
+ *  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.Collections.Generic;
+
+namespace React
+{
+	/// <summary>
+	/// Represents the data contained in a source map
+	/// </summary>
+	[Serializable]
+	public class SourceMap
+	{
+		/// <summary>
+		/// Version number of the source map spec used to build this source map. Expected
+		/// to be version 3.
+		/// </summary>
+		public int Version { get; set; }
+
+		/// <summary>
+		/// An optional name of the generated code that this source map is associated with.
+		/// </summary>
+		public string File { get; set; }
+
+		/// <summary>
+		/// An optional source root, useful for relocating source files on a server or
+		/// removing repeated values in the <see cref="Sources"/> entry.  This value is 
+		/// prepended to the individual entries in the <see cref="Sources"/> field.
+		/// </summary>
+		public string SourceRoot { get; set; }
+
+		/// <summary>
+		/// A list of original sources used by the <see cref="Mappings"/> entry.
+		/// </summary>
+		public IList<string> Sources { get; set; }
+
+		/// <summary>
+		/// An optional list of source content, useful when the <see cref="Sources"/> can't 
+		/// be hosted. The contents are listed in the same order as the <see cref="Sources"/>. 
+		/// <c>null</c> may be used if some original sources should be retrieved by name.
+		/// </summary>
+		public IList<string> SourcesContent { get; set; }
+
+		/// <summary>
+		/// A list of symbol names used by the <see cref="Mappings"/> entry.
+		/// </summary>
+		public IList<string> Names { get; set; }
+
+		/// <summary>
+		/// A string with the mapping data encoded in base 64 VLQ.
+		/// </summary>
+		public string Mappings { get; set; }
+	}
+}