Expose interface to call the dart-sass executable during runtime

.github/workflows/dotnetcore.yml

@@ -27,6 +27,8 @@ jobs:
       run: dotnet restore
     - name: Build
       run: dotnet build --configuration Release --no-restore
+    - name: Test
+      run: dotnet test --configuration Release --no-build
     - name: Validate generated css files
       run: |
         test -s Samples/AspNetCore.SassCompiler.BlazorSample/Components/Pages/Counter.razor.css

AspNetCore.SassCompiler.Tests/AspNetCore.SassCompiler.Tests.csproj

@@ -0,0 +1,43 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <SassCompilerIncludeRuntime>true</SassCompilerIncludeRuntime>
+  </PropertyGroup>
+
+  <!-- Only needed because we're using a ProjectReference, this is done implicitly for PackageReference's -->
+  <Import Project="..\AspNetCore.SassCompiler\build\AspNetCore.SassCompiler.props" />
+
+  <PropertyGroup>
+    <TargetFramework>net6.0</TargetFramework>
+    <Nullable>enable</Nullable>
+    <ImplicitUsings>enable</ImplicitUsings>
+
+    <IsPackable>false</IsPackable>
+  </PropertyGroup>
+
+  <PropertyGroup>
+    <SassCompilerTasksAssembly Condition=" '$(Configuration)' != '' ">$(MSBuildThisFileDirectory)..\AspNetCore.SassCompiler.Tasks\bin\$(Configuration)\netstandard2.0\AspNetCore.SassCompiler.Tasks.dll</SassCompilerTasksAssembly>
+    <SassCompilerTasksAssembly Condition=" '$(Configuration)' == '' ">$(MSBuildThisFileDirectory)..\AspNetCore.SassCompiler.Tasks\bin\Debug\netstandard2.0\AspNetCore.SassCompiler.Tasks.dll</SassCompilerTasksAssembly>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.9.0" />
+    <PackageReference Include="xunit" Version="2.7.0" />
+    <PackageReference Include="xunit.runner.visualstudio" Version="2.5.7">
+      <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
+      <PrivateAssets>all</PrivateAssets>
+    </PackageReference>
+    <PackageReference Include="coverlet.collector" Version="6.0.1">
+      <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
+      <PrivateAssets>all</PrivateAssets>
+    </PackageReference>
+  </ItemGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\AspNetCore.SassCompiler\AspNetCore.SassCompiler.csproj" />
+  </ItemGroup>
+
+  <!-- Only needed because we're using a ProjectReference, this is done implicitly for PackageReference's -->
+  <Import Project="..\AspNetCore.SassCompiler\build\AspNetCore.SassCompiler.targets" />
+
+</Project>

AspNetCore.SassCompiler.Tests/SassCompilerTests.cs

@@ -0,0 +1,118 @@
+using System.Text;
+using Microsoft.Extensions.Logging.Abstractions;
+using Xunit;
+
+namespace AspNetCore.SassCompiler.Tests;
+
+public class SassCompilerTests
+{
+    [Fact]
+    public async Task CompileAsync_WithoutStreams_Success()
+    {
+        // Arrange
+        var sassCompiler = new SassCompiler(NullLogger<SassCompiler>.Instance);
+
+        var tempDirectory = Path.Join(Path.GetTempPath(), Path.GetRandomFileName());
+        Directory.CreateDirectory(tempDirectory);
+
+        try
+        {
+            await File.WriteAllTextAsync(Path.Join(tempDirectory, "input"), "body { color: black; }");
+
+            // Act
+            await sassCompiler.CompileAsync(new[] { Path.Join(tempDirectory, "input"), Path.Join(tempDirectory, "output"), "--no-source-map" });
+            var result = await File.ReadAllTextAsync(Path.Join(tempDirectory, "output"));
+
+            // Assert
+            Assert.Equal("body {\n  color: black;\n}\n", result);
+        }
+        finally
+        {
+            Directory.Delete(tempDirectory, true);
+        }
+    }
+
+    [Theory]
+    [InlineData("--watch")]
+    [InlineData("--interactive")]
+    public async Task CompileAsync_ThrowsWithInvalidArguments(string argument)
+    {
+        // Arrange
+        var sassCompiler = new SassCompiler(NullLogger<SassCompiler>.Instance);
+
+        var input = new MemoryStream(Encoding.UTF8.GetBytes("body { color: black; }"));
+
+        // Act
+        async Task Act() => await sassCompiler.CompileAsync(input, new[] { argument });
+
+        // Assert
+        var exception = await Assert.ThrowsAsync<SassCompilerException>(Act);
+        Assert.Equal($"The sass {argument} option is not supported.", exception.Message);
+        Assert.Null(exception.ErrorOutput);
+    }
+
+    [Fact]
+    public async Task CompileAsync_ThrowsWithInvalidInput()
+    {
+        // Arrange
+        var sassCompiler = new SassCompiler(NullLogger<SassCompiler>.Instance);
+
+        var input = new MemoryStream(Encoding.UTF8.GetBytes("body { color: black;"));
+
+        // Act
+        async Task Act() => await sassCompiler.CompileAsync(input, Array.Empty<string>());
+
+        // Assert
+        var exception = await Assert.ThrowsAsync<SassCompilerException>(Act);
+        Assert.Equal("Sass process exited with non-zero exit code: 65.", exception.Message);
+        Assert.StartsWith("Error: expected \"}\".", exception.ErrorOutput);
+    }
+
+    [Fact]
+    public async Task CompileAsync_ReturningOutputStream_Success()
+    {
+        // Arrange
+        var sassCompiler = new SassCompiler(NullLogger<SassCompiler>.Instance);
+
+        var input = new MemoryStream(Encoding.UTF8.GetBytes("body { color: black; }"));
+
+        // Act
+        var output = await sassCompiler.CompileAsync(input, Array.Empty<string>());
+        var result = await new StreamReader(output).ReadToEndAsync();
+
+        // Assert
+        Assert.Equal("body {\n  color: black;\n}\n", result);
+    }
+
+    [Fact]
+    public async Task CompileAsync_WithInputAndOutputStream_Success()
+    {
+        // Arrange
+        var sassCompiler = new SassCompiler(NullLogger<SassCompiler>.Instance);
+
+        var input = new MemoryStream(Encoding.UTF8.GetBytes("body { color: black; }"));
+        var output = new MemoryStream();
+
+        // Act
+        await sassCompiler.CompileAsync(input, output, Array.Empty<string>());
+        var result = Encoding.UTF8.GetString(output.ToArray());
+
+        // Assert
+        Assert.Equal("body {\n  color: black;\n}\n", result);
+    }
+
+    [Fact]
+    public async Task CompileToStringAsync_Success()
+    {
+        // Arrange
+        var sassCompiler = new SassCompiler(NullLogger<SassCompiler>.Instance);
+
+        var input = new MemoryStream(Encoding.UTF8.GetBytes("body { color: black; }"));
+
+        // Act
+        var result = await sassCompiler.CompileToStringAsync(input, Array.Empty<string>());
+
+        // Assert
+        Assert.Equal("body {\n  color: black;\n}\n", result);
+    }
+}

AspNetCore.SassCompiler.sln

@@ -20,6 +20,8 @@ Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "AspNetCore.SassCompiler.Bla
 EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "AspNetCore.SassCompiler.RazorClassLibrary", "Samples\AspNetCore.SassCompiler.RazorClassLibrary\AspNetCore.SassCompiler.RazorClassLibrary.csproj", "{B318D98D-B145-4ACF-8B48-D601FB5C91E4}"
 EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "AspNetCore.SassCompiler.Tests", "AspNetCore.SassCompiler.Tests\AspNetCore.SassCompiler.Tests.csproj", "{0ACD7A9B-8D2A-4274-86F8-0FA4A2413903}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -50,6 +52,10 @@ Global
 		{B318D98D-B145-4ACF-8B48-D601FB5C91E4}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{B318D98D-B145-4ACF-8B48-D601FB5C91E4}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{B318D98D-B145-4ACF-8B48-D601FB5C91E4}.Release|Any CPU.Build.0 = Release|Any CPU
+		{0ACD7A9B-8D2A-4274-86F8-0FA4A2413903}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{0ACD7A9B-8D2A-4274-86F8-0FA4A2413903}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{0ACD7A9B-8D2A-4274-86F8-0FA4A2413903}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{0ACD7A9B-8D2A-4274-86F8-0FA4A2413903}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE

AspNetCore.SassCompiler/AspNetCore.SassCompiler.csproj

@@ -32,6 +32,10 @@
     <ProjectReference Include="..\AspNetCore.SassCompiler.Tasks\AspNetCore.SassCompiler.Tasks.csproj" ReferenceOutputAssembly="false" PrivateAssets="All" />
   </ItemGroup>
 
+  <ItemGroup>
+    <InternalsVisibleTo Include="AspNetCore.SassCompiler.Tests" />
+  </ItemGroup>
+
   <ItemGroup>
     <None Include="build\*" Pack="true" PackagePath="build" />
     <None Include="runtimes\**" Pack="true" PackagePath="runtimes" />

AspNetCore.SassCompiler/ChildProcessTracker.cs

@@ -11,7 +11,7 @@ namespace AspNetCore.SassCompiler
     /// <remarks>References:
     ///  https://stackoverflow.com/a/4657392/386091
     ///  https://stackoverflow.com/a/9164742/386091 </remarks>
-    public static class ChildProcessTracker
+    internal static class ChildProcessTracker
     {
         /// <summary>
         /// Add the process to be tracked. If our current process is killed, the child processes