TypedPaths.Generator 1.2.8

TypedPaths.Generator

A Roslyn source generator that turns configured folder trees into strongly typed path constants at compile time. Each configured folder becomes a nested static class (for example Src, Template) so you can avoid magic strings.

What you get

Given a structure like:

/src
  Template1.anyext
  folderA/
    Template2.anyext
  folderB/
    Template3.anyext
    Template4.anyext
/template
  email/
    welcome.txt
  sms/
    otp.txt

the generator emits one file per root folder (TypedPaths.Src.g.cs, TypedPaths.Template.g.cs, ...), each contributing to the same partial root class:

// TypedPaths.Src.g.cs
// <auto-generated/>
namespace TypedPaths;

public static partial class TypedPaths
{
    public static partial class Src
    {
        public const string Value = "src";

        public static partial class Template1
        {
            public const string Value = "src/Template1.anyext";
        }

        public static partial class FolderA
        {
            public const string Value = "src/folderA";

            public static partial class Template2
            {
                public const string Value = "src/folderA/Template2.anyext";
            }
        }

        public static partial class FolderB
        {
            public const string Value = "src/folderB";

            public static partial class Template3
            {
                public const string Value = "src/folderB/Template3.anyext";
            }

            public static partial class Template4
            {
                public const string Value = "src/folderB/Template4.anyext";
            }
        }
    }
}

// TypedPaths.Template.g.cs
// <auto-generated/>
namespace TypedPaths;

public static partial class TypedPaths
{
    public static partial class Template
    {
        public const string Value = "template";

        public static partial class Email
        {
            public const string Value = "template/email";

            public static partial class Welcome
            {
                public const string Value = "template/email/welcome.txt";
            }
        }

        public static partial class Sms
        {
            public const string Value = "template/sms";

            public static partial class Otp
            {
                public const string Value = "template/sms/otp.txt";
            }
        }
    }
}

So you can use TypedPaths.Src.FolderA.Template2.Value and TypedPaths.Template.Email.Welcome.Value instead of raw string paths.

Requirements

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

Setup

Option A: consume from NuGet (recommended)

<ItemGroup>
  <PackageReference Include="TypedPaths.Generator" Version="1.0.0" />
</ItemGroup>

<ItemGroup>
  <TypedPathsFolder Include="src" ClassName="Src" />
  <TypedPathsFolder Include="template" />
</ItemGroup>

That is the only configuration needed in consumer projects.
TypedPaths.Generator.targets (from package build) automatically maps each TypedPathsFolder to AdditionalFiles for source generation.

Option B: local project reference (repository development)

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

<ItemGroup>
  <TypedPathsFolder Include="src" ClassName="Src" />
  <TypedPathsFolder Include="template" />
</ItemGroup>

<Import Project="..\TypedPaths.Generator\build\TypedPaths.Generator.targets"
        Condition="Exists('..\TypedPaths.Generator\build\TypedPaths.Generator.targets')" />

The explicit <Import /> is required only for local project-reference scenarios.

Build the project; the generator runs and adds TypedPaths.*.g.cs files 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;

// Always read .Value (works for both folder and file nodes)
string folderPath = TypedPathsRoot.Src.FolderA.Value; // "src/folderA"
string filePath = TypedPathsRoot.Src.FolderA.Template2.Value;  // "src/folderA/Template2.anyext"
string emailTemplate = TypedPathsRoot.Template.Email.Welcome.Value; // "template/email/welcome.txt"

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

Value is always a path relative to the project root:

• Folder node Value = relative folder path
• File node Value = relative file path (including extension)

Nested child classes are emitted only for folders (because only folders can contain files/subfolders).

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.
• If a folder name and file name conflict in the same scope:
  • the folder keeps the base name;
  • the file name becomes FileName + ExtensionWithoutDot (example: report/ + report.txt → Report and ReportTxt);
  • if the conflicting file has no extension, use File suffix (example: data/ + data → Data and DataFile).

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.