Purview.SourceGeneratorFramework 1.0.0-prerelease.5

Purview.SourceGeneratorFramework

Core helpers, models, and MSBuild integration for writing incremental C# source generators with Roslyn.

Installation

dotnet add package Purview.SourceGeneratorFramework

What's included

• CodeWriter — allocation-conscious helper for building generated C# source files with indentation, namespaces, type declarations, comments, and XML documentation.
• IncrementalPipeline — extension methods for composing IncrementalValueProvider<T> and IncrementalValuesProvider<T> pipelines, including attribute-based discovery, generation context creation, and disable-property checks.
• GenerationContext — a base context record that carries the Roslyn Compilation and a shared CodeWriter.
• GeneratorResult<T> — a value-or-diagnostics result type for incremental source generator transforms.
• TypeValueObject, TargetSymbolDescriptor, EquatableArray<T>, DiagnosticInfo — reusable models for generator inputs and outputs.
• SymbolResolver, TypeHelpers, EmbeddedResources — helper classes for common symbol and resource tasks.
• MSBuild .props / .targets — automatically adds global using directives for the main namespaces and supports packaging source generators that reference this framework.

Usage

Reference the package from a Roslyn source generator project:

<Project Sdk="Microsoft.NET.Sdk">
  <PropertyGroup>
    <TargetFramework>netstandard2.0</TargetFramework>
    <IsRoslynComponent>true</IsRoslynComponent>
    <EnforceExtendedAnalyzerRules>true</EnforceExtendedAnalyzerRules>
  </PropertyGroup>

  <ItemGroup>
    <PackageReference Include="Purview.SourceGeneratorFramework" />
    <PackageReference Include="Microsoft.CodeAnalysis.CSharp" PrivateAssets="all" />
    <PackageReference Include="Microsoft.CodeAnalysis.Analyzers" PrivateAssets="all" />
  </ItemGroup>
</Project>

Implement IIncrementalGenerator and use the framework helpers to build a pipeline:

using Microsoft.CodeAnalysis;
using Purview.SourceGeneratorFramework.Helpers;
using Purview.SourceGeneratorFramework.Models;

[Generator]
public sealed class MyGenerator : IIncrementalGenerator
{
    static readonly TypeValueObject AttributeType = new("MyAttribute", "MyNamespace");

    public void Initialize(IncrementalGeneratorInitializationContext context)
    {
        var contextProvider = IncrementalPipeline.DefaultGenerationContextValueProvider(context);

        var targets = IncrementalPipeline.ForAttributeWithMetadataName(
            context,
            AttributeType,
            static (ctx, ct) => ctx.TargetSymbol.Name
        );

        context.RegisterSourceOutput(
            targets.CombineWithContext(contextProvider),
            static (spc, pair) =>
            {
                var (name, generationContext) = pair;
                var writer = new CodeWriter();
                writer.WriteAutoGeneratedHeader(nameof(MyGenerator));
                writer.WriteFileScopedNamespace("MyNamespace");
                using (writer.WriteClass($"public static partial class {name}"))
                {
                    writer.WriteLine("// generated content");
                }

                spc.AddSource($"{name}.g.cs", writer.ToString());
            }
        );
    }
}

See SourceGeneratorFramework.ExampleGenerator for a complete reference implementation.

Disabling a generator at build time

Use IncrementalPipeline.IsDisabledValueProvider to read an MSBuild analyzer-config property and skip generation when it is set to true:

<PropertyGroup>
  <MyGenerator_Disable>true</MyGenerator_Disable>
</PropertyGroup>

var isDisabled = IncrementalPipeline.IsDisabledValueProvider(context, "MyGenerator_Disable");

License

This project is licensed under the MIT license.