Adds Sass template processing

Wyam.sln

@@ -122,6 +122,10 @@ Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Wyam.Hosting", "src\core\Wy
 EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Wyam.Hosting.Tests", "tests\core\Wyam.Hosting.Tests\Wyam.Hosting.Tests.csproj", "{9C59DA3D-6A41-4DC4-A4BB-0927C6978367}"
 EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Wyam.Sass", "src\extensions\Wyam.Sass\Wyam.Sass.csproj", "{90A0AB19-0146-4931-BEFA-D895B192E050}"
+EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Wyam.Sass.Tests", "tests\extensions\Wyam.Sass.Tests\Wyam.Sass.Tests.csproj", "{A6B7B1A6-7BE5-4E98-9286-D03A0F936E98}"
+EndProject
 Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "misc", "misc", "{9B01F618-6AB3-4DCD-A044-4CA58EEF6419}"
 	ProjectSection(SolutionItems) = preProject
 		.editorconfig = .editorconfig
@@ -332,6 +336,14 @@ Global
 		{9C59DA3D-6A41-4DC4-A4BB-0927C6978367}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{9C59DA3D-6A41-4DC4-A4BB-0927C6978367}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{9C59DA3D-6A41-4DC4-A4BB-0927C6978367}.Release|Any CPU.Build.0 = Release|Any CPU
+		{90A0AB19-0146-4931-BEFA-D895B192E050}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{90A0AB19-0146-4931-BEFA-D895B192E050}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{90A0AB19-0146-4931-BEFA-D895B192E050}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{90A0AB19-0146-4931-BEFA-D895B192E050}.Release|Any CPU.Build.0 = Release|Any CPU
+		{A6B7B1A6-7BE5-4E98-9286-D03A0F936E98}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{A6B7B1A6-7BE5-4E98-9286-D03A0F936E98}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{A6B7B1A6-7BE5-4E98-9286-D03A0F936E98}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{A6B7B1A6-7BE5-4E98-9286-D03A0F936E98}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE
@@ -393,5 +405,7 @@ Global
 		{95080CB0-DC4E-4617-8F73-6E06A6CA2F5F} = {4813B17D-EFCA-401D-B0E6-7B24B3946A70}
 		{A3041B22-8A32-4ADB-89F3-A808AC60899B} = {4813B17D-EFCA-401D-B0E6-7B24B3946A70}
 		{9C59DA3D-6A41-4DC4-A4BB-0927C6978367} = {12931CA5-E734-4CD9-883D-27D897512183}
+		{90A0AB19-0146-4931-BEFA-D895B192E050} = {5A431149-2B88-40C3-9717-CA6CCF214317}
+		{A6B7B1A6-7BE5-4E98-9286-D03A0F936E98} = {2E5842F3-4797-4BB5-9A55-F3A005B434F8}
 	EndGlobalSection
 EndGlobal

src/core/Wyam.Configuration/KnownExtensionGenerated.cs

@@ -24,6 +24,7 @@ public partial class KnownExtension
 		public static readonly KnownExtension Markdown = new KnownExtension("Wyam.Markdown");
 		public static readonly KnownExtension Minification = new KnownExtension("Wyam.Minification");
 		public static readonly KnownExtension Razor = new KnownExtension("Wyam.Razor");
+		public static readonly KnownExtension Sass = new KnownExtension("Wyam.Sass");
 		public static readonly KnownExtension SearchIndex = new KnownExtension("Wyam.SearchIndex");
 		public static readonly KnownExtension Tables = new KnownExtension("Wyam.Tables");
 		public static readonly KnownExtension TextGeneration = new KnownExtension("Wyam.TextGeneration");

src/extensions/Wyam.Sass/Properties/AssemblyInfo.cs

@@ -0,0 +1,8 @@
+using System.Reflection;
+using System.Runtime.CompilerServices;
+using System.Runtime.InteropServices;
+
+[assembly: AssemblyTitle("Wyam.Sass")]
+[assembly: AssemblyDescription("")]
+[assembly: ComVisible(false)]
+[assembly: Guid("90a0ab19-0146-4931-befa-d895b192e050")]

src/extensions/Wyam.Sass/Sass.cs

@@ -0,0 +1,153 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using LibSass.Compiler;
+using LibSass.Compiler.Options;
+using Wyam.Common.Documents;
+using Wyam.Common.Execution;
+using Wyam.Common.IO;
+using Wyam.Common.Meta;
+using Wyam.Common.Modules;
+using Wyam.Common.Tracing;
+using Wyam.Common.Util;
+
+namespace Wyam.Sass
+{
+    /// <summary>
+    /// Compiles Sass CSS files to CSS stylesheets.
+    /// </summary>
+    /// <remarks>
+    /// The content of the input document is compiled to CSS and the content of the output document contains the compiled CSS stylesheet.
+    /// </remarks>
+    /// <example>
+    /// This is a pipeline that compiles two Sass CSS files, one for Bootstrap (which contains a lot of includes) and a second for custom CSS.
+    /// <code>
+    /// Pipelines.Add("Sass",
+    ///     ReadFiles("master.scss"),
+    ///     Concat(ReadFiles("foundation.scss")),
+    ///     Sass().WithCompactOutputStyle(),
+    ///     WriteFiles(".css")
+    /// );
+    /// </code>
+    /// </example>
+    /// <category>Templates</category>
+    public class Sass : IModule
+    {
+        private readonly List<string> _includePaths = new List<string>();
+        private bool _includeSourceComments = true;
+        private SassOutputStyle _outputStyle = SassOutputStyle.Compact;
+
+        /// <summary>
+        /// Adds a list of paths to search while processing includes.
+        /// </summary>
+        /// <param name="paths">The paths to include.</param>
+        /// <returns>The current instance.</returns>
+        public Sass WithIncludePaths(IEnumerable<string> paths)
+        {
+            _includePaths.AddRange(paths);
+            return this;
+        }
+
+        /// <summary>
+        /// Adds a path to search while processing includes.
+        /// </summary>
+        /// <param name="path">The path to include.</param>
+        /// <returns>The current instance.</returns>
+        public Sass WithIncludePath(string path)
+        {
+            _includePaths.Add(path);
+            return this;
+        }
+
+        /// <summary>
+        /// Sets whether the source comments are included
+        /// </summary>
+        /// <param name="includeSourceComments">The default value is <c>true</c></param>
+        /// <returns>The current instance.</returns>
+        public Sass IncludeSourceComments(bool includeSourceComments = true)
+        {
+            _includeSourceComments = includeSourceComments;
+            return this;
+        }
+
+        /// <summary>
+        /// Sets the output style to compact.
+        /// </summary>
+        /// <returns>The current instance.</returns>
+        public Sass WithCompactOutputStyle()
+        {
+            _outputStyle = SassOutputStyle.Compact;
+            return this;
+        }
+
+
+        /// <summary>
+        /// Sets the output style to expanded.
+        /// </summary>
+        /// <returns>The current instance.</returns>
+        public Sass WithExpandedOutputStyle()
+        {
+            _outputStyle = SassOutputStyle.Expanded;
+            return this;
+        }
+
+        /// <summary>
+        /// Sets the output style to compressed.
+        /// </summary>
+        /// <returns>The current instance.</returns>
+        public Sass WithCompressedOutputStyle()
+        {
+            _outputStyle = SassOutputStyle.Compressed;
+            return this;
+        }
+
+        /// <summary>
+        /// Sets the output style to nested.
+        /// </summary>
+        /// <returns>The current instance.</returns>
+        public Sass WithNestedOutputStyle()
+        {
+            _outputStyle = SassOutputStyle.Nested;
+            return this;
+        }
+
+        public IEnumerable<IDocument> Execute(IReadOnlyList<IDocument> inputs, IExecutionContext context)
+        {
+            return inputs.AsParallel().Select(context, input =>
+            {
+                Trace.Verbose("Processing Sass for {0}", input.SourceString());
+
+                FilePath path = input.FilePath(Keys.SourceFilePath);
+                SassOptions sassOptions = new SassOptions
+                {
+                    Data = input.Content,
+                    IncludeSourceComments = _includeSourceComments,
+                    OutputStyle = _outputStyle,
+                    IncludePaths = path == null
+                        ? _includePaths.ToArray()
+                        : new List<string>(_includePaths) { path.Directory.FullPath }.ToArray()
+                };
+
+                SassCompiler sassCompiler = new SassCompiler(sassOptions);
+                SassResult sassResult ;
+                try
+                {
+                    sassResult = sassCompiler.Compile();
+                }
+                catch (Exception ex)
+                {
+                    Trace.Warning("Exception while compiling sass file {0}: {}", input.SourceString(), ex.ToString());
+                    return context.GetDocument(input, input.SourceString());
+                }
+
+                if (sassResult.ErrorStatus != 0)
+                {
+                    Trace.Warning("Exception while compiling sass file {0}: {1}", input.SourceString(), sassResult.ErrorMessage);
+                    return context.GetDocument(input, input.SourceString());
+                }
+
+                return context.GetDocument(input, sassResult.Output);
+            });
+        }
+    }
+}

src/extensions/Wyam.Sass/Wyam.Sass.csproj

@@ -0,0 +1,79 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="14.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props" Condition="Exists('$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props')" />
+  <PropertyGroup>
+    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
+    <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
+    <ProjectGuid>{90A0AB19-0146-4931-BEFA-D895B192E050}</ProjectGuid>
+    <OutputType>Library</OutputType>
+    <AppDesignerFolder>Properties</AppDesignerFolder>
+    <RootNamespace>Wyam.Sass</RootNamespace>
+    <AssemblyName>Wyam.Sass</AssemblyName>
+    <TargetFrameworkVersion>v4.6.2</TargetFrameworkVersion>
+    <FileAlignment>512</FileAlignment>
+    <NuGetPackageImportStamp>
+    </NuGetPackageImportStamp>
+  </PropertyGroup>
+  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
+    <DebugSymbols>true</DebugSymbols>
+    <DebugType>full</DebugType>
+    <Optimize>false</Optimize>
+    <OutputPath>bin\Debug\</OutputPath>
+    <DefineConstants>DEBUG;TRACE</DefineConstants>
+    <ErrorReport>prompt</ErrorReport>
+    <WarningLevel>4</WarningLevel>
+  </PropertyGroup>
+  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
+    <DebugType>pdbonly</DebugType>
+    <Optimize>true</Optimize>
+    <OutputPath>bin\Release\</OutputPath>
+    <DefineConstants>TRACE</DefineConstants>
+    <ErrorReport>prompt</ErrorReport>
+    <WarningLevel>4</WarningLevel>
+  </PropertyGroup>
+  <ItemGroup>
+    <Reference Include="LibSass.NET, Version=4.0.0.0, Culture=neutral, processorArchitecture=MSIL">
+      <HintPath>..\..\..\packages\libsassnet.3.3.7\lib\net40\LibSass.NET.dll</HintPath>
+      <Private>True</Private>
+    </Reference>
+    <Reference Include="System" />
+    <Reference Include="System.Core" />
+    <Reference Include="System.Xml.Linq" />
+    <Reference Include="System.Data.DataSetExtensions" />
+    <Reference Include="Microsoft.CSharp" />
+    <Reference Include="System.Data" />
+    <Reference Include="System.Net.Http" />
+    <Reference Include="System.Xml" />
+  </ItemGroup>
+  <ItemGroup>
+    <Compile Include="Sass.cs" />
+    <Compile Include="Properties\AssemblyInfo.cs" />
+	<Compile Include="..\..\..\SolutionInfo.cs">
+      <Link>Properties\SolutionInfo.cs</Link>
+    </Compile>
+  </ItemGroup>
+  <ItemGroup>
+    <ProjectReference Include="..\..\core\Wyam.Common\Wyam.Common.csproj">
+      <Project>{F40B73E9-C0CC-465C-925E-B51E686C1D5C}</Project>
+      <Name>Wyam.Common</Name>
+    </ProjectReference>
+  </ItemGroup>
+  <ItemGroup>
+    <None Include="packages.config" />
+  </ItemGroup>
+  <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />
+  <Import Project="..\..\..\packages\libsassnet.3.3.7\build\libsassnet.targets" Condition="Exists('..\..\..\packages\libsassnet.3.3.7\build\libsassnet.targets')" />
+  <Target Name="EnsureNuGetPackageBuildImports" BeforeTargets="PrepareForBuild">
+    <PropertyGroup>
+      <ErrorText>This project references NuGet package(s) that are missing on this computer. Use NuGet Package Restore to download them.  For more information, see http://go.microsoft.com/fwlink/?LinkID=322105. The missing file is {0}.</ErrorText>
+    </PropertyGroup>
+    <Error Condition="!Exists('..\..\..\packages\libsassnet.3.3.7\build\libsassnet.targets')" Text="$([System.String]::Format('$(ErrorText)', '..\..\..\packages\libsassnet.3.3.7\build\libsassnet.targets'))" />
+  </Target>
+  <!-- To modify your build process, add your task inside one of the targets below and uncomment it. 
+       Other similar extension points exist, see Microsoft.Common.targets.
+  <Target Name="BeforeBuild">
+  </Target>
+  <Target Name="AfterBuild">
+  </Target>
+  -->
+</Project>

src/extensions/Wyam.Sass/Wyam.Sass.nuspec

@@ -0,0 +1,18 @@
+<?xml version="1.0"?>
+<package >
+  <metadata>
+    <id>Wyam.Sass</id>
+    <version>$version$</version>
+    <title>Wyam.Sass</title>
+    <authors>Dave Glick</authors>
+    <owners>Dave Glick</owners>
+    <licenseUrl>https://github.com/Wyamio/Wyam/blob/master/LICENSE</licenseUrl>
+    <iconUrl>https://wyam.io/Content/images/logo-square-64.png</iconUrl>
+    <projectUrl>https://wyam.io</projectUrl>
+    <requireLicenseAcceptance>false</requireLicenseAcceptance>
+    <description>Wyam is a simple to use, highly modular, and extremely configurable static content generator. This library provides support for parsing Sass CSS content.</description>
+    <copyright>Copyright 2016</copyright>
+    <tags>Wyam Static StaticContent StaticSite Blog BlogEngine CSS Sass SassCSS</tags>
+  </metadata>
+  <files></files>
+</package>

src/extensions/Wyam.Sass/packages.config

@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="utf-8"?>
+<packages>
+  <package id="libsassnet" version="3.3.7" targetFramework="net462" />
+</packages>

tests/extensions/Wyam.Sass.Tests/Properties/AssemblyInfo.cs

@@ -0,0 +1,8 @@
+using System.Reflection;
+using System.Runtime.CompilerServices;
+using System.Runtime.InteropServices;
+
+[assembly: AssemblyTitle("Wyam.Sass.Tests")]
+[assembly: AssemblyDescription("")]
+[assembly: ComVisible(false)]
+[assembly: Guid("a6b7b1a6-7be5-4e98-9286-d03a0f936e98")]

tests/extensions/Wyam.Sass.Tests/SassFixture.cs

@@ -0,0 +1,68 @@
+using System;
+using System.Linq;
+using NSubstitute;
+using NUnit.Framework;
+using Wyam.Common.Documents;
+using Wyam.Common.Execution;
+using Wyam.Testing;
+
+namespace Wyam.Sass.Tests
+{
+    [TestFixture]
+    [Parallelizable(ParallelScope.Self | ParallelScope.Children)]
+    public class SassFixture : BaseFixture
+    {
+        [Test]
+        public void Convert()
+        {
+            string input = @"
+$font-stack:    Helvetica, sans-serif;
+$primary-color: #333;
+
+body {
+  font: 100% $font-stack;
+  color: $primary-color;
+}";
+
+            string output = "body { font: 100% Helvetica, sans-serif; color: #333; }\n";
+
+            IExecutionContext context = Substitute.For<IExecutionContext>();
+            IDocument document = Substitute.For<IDocument>();
+            document.Content.Returns(input);
+
+            Sass sass = new Sass().IncludeSourceComments(false).WithCompactOutputStyle();
+
+            // When
+            sass.Execute(new[] { document }, context).ToList();  // Make sure to materialize the result list
+
+            // Then
+            context.Received(1).GetDocument(Arg.Any<IDocument>(), Arg.Any<string>());
+            context.Received().GetDocument(document, output);
+        }
+
+        [Test]
+        public void ConvertingBadSassFails()
+        {
+            string input = @"
+$font-stack:    Helvetica, sans-serif
+$primary-color: #333
+
+body {
+  font: 100% $font-stack;
+  color: $primary-color;
+}";
+
+            IExecutionContext context = Substitute.For<IExecutionContext>();
+            IDocument document = Substitute.For<IDocument>();
+            document.Content.Returns(input);
+
+            Sass sass = new Sass();
+
+            // That
+            Assert.Catch<AggregateException>(() => 
+            {
+                sass.Execute(new[] { document }, context).ToList();  // Make sure to materialize the result list
+            });
+        }
+    }
+}