TypedPaths.Generator 1.0.0

TypedPaths.Generator

A Roslyn source generator that turns a folder tree into strongly typed path constants at compile time. Point it at a base path (e.g. /src or /templates), and get nested static classes and const string members you can use instead of magic strings.

What you get

Given a structure like:

/src
  Template1.anyext
  folderA/
    Template2.anyext
  folderB/
    Template3.anyext
    Template4.anyext

the generator emits a single file TypedPaths.g.cs with:

namespace TypedPaths;

public static class TypedPaths
{
    public static class Src
    {
        public const string Template1 = "src/Template1.anyext";
        public static class FolderA
        {
            public const string Template2 = "src/folderA/Template2.anyext";
        }
        public static class FolderB
        {
            public const string Template3 = "src/folderB/Template3.anyext";
            public const string Template4 = "src/folderB/Template4.anyext";
        }
    }
}

So you can use TypedPaths.Src.FolderA.Template2 instead of "src/folderA/Template2.anyext" and keep paths refactor-safe and discoverable.

Requirements

• .NET 8 (or the TFM your project uses; the generator targets .NET Standard 2.0)
• MSBuild / SDK-style projects

Setup

1. Reference the generator (as an analyzer, not a normal assembly):

   <ItemGroup>
     <ProjectReference Include="path\to\TypedPaths.Generator\TypedPaths.Generator.csproj"
                       OutputItemType="Analyzer"
                       ReferenceOutputAssembly="false" />
   </ItemGroup>
   

2. Set the base path (any relative path you want to expose as typed paths):

   <PropertyGroup>
     <TypedPathsBasePath>/src</TypedPathsBasePath>
   </PropertyGroup>
   
   <ItemGroup>
     <CompilerVisibleProperty Include="TypedPathsBasePath" />
   </ItemGroup>
   

   Examples: /src, src, /templates, /assets/email.

3. Include the files under that path as AdditionalFiles so the generator can see them:

   <ItemGroup>
     <AdditionalFiles Include="src\**\*" />
   </ItemGroup>
   

Build the project; the generator runs and adds TypedPaths.g.cs to the compilation.

Usage in code

The generated type is in namespace TypedPaths, and the root class is also named TypedPaths. To avoid name clashes, use an alias:

using TypedPathsRoot = TypedPaths.TypedPaths;

// Use as const strings
string path = TypedPathsRoot.Src.FolderA.Template2;  // "src/folderA/Template2.anyext"

// e.g. resolve to full path
var fullPath = Path.Combine(projectRoot, TypedPathsRoot.Src.FolderA.Template2);

Naming rules

• Folder and file names become PascalCase identifiers.
• Invalid identifier characters are dropped or split; leading digits get a _ prefix.
• Duplicate names in the same scope get suffixes: _2, _3, etc.
• Extensions are stripped from member names but kept in the path string.

Repository layout

Build and test

dotnet restore
dotnet build
dotnet test

Run the sample:

dotnet run --project TypedPaths.Generator.Sample

License

See the repository for license information.