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 defining a top-level static class in the TypedPaths namespace:

// TypedPaths.Src.g.cs // <auto-generated/> namespace TypedPaths; public static class Src { public const string Value = "src"; public static class Template1 { public const string Value = "src/Template1.anyext"; } public static class FolderA { public const string Value = "src/folderA"; public static class Template2 { public const string Value = "src/folderA/Template2.anyext"; } } public static class FolderB { public const string Value = "src/folderB"; public static class Template3 { public const string Value = "src/folderB/Template3.anyext"; } public static class Template4 { public const string Value = "src/folderB/Template4.anyext"; } } } // TypedPaths.Template.g.cs // <auto-generated/> namespace TypedPaths; public static class Template { public const string Value = "template"; public static class Email { public const string Value = "template/email"; public static class Welcome { public const string Value = "template/email/welcome.txt"; } } public static class Sms { public const string Value = "template/sms"; public static class Otp { public const string Value = "template/sms/otp.txt"; } } }

With using TypedPaths; you can use Src.FolderA.Template2.Value and 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

Add using TypedPaths; and use the generated classes directly. Each configured root folder becomes a top-level static class (e.g. Src, Template):

using TypedPaths; // Always read .Value (works for both folder and file nodes) string folderPath = Src.FolderA.Value; // "src/folderA" string filePath = Src.FolderA.Template2.Value; // "src/folderA/Template2.anyext" string emailTemplate = Template.Email.Welcome.Value; // "template/email/welcome.txt" // e.g. resolve to full path var fullPath = Path.Combine(projectRoot, 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

Project	Description
TypedPaths.Generator	The source generator (Roslyn incremental generator).
TypedPaths.Generator.Sample	Example app that uses the generator and runs a small demo.
TypedPaths.Generator.Tests	Unit tests for the generator.

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.