@tsonic/dotnet

TypeScript declarations and CLR binding metadata for the .NET 10 base class library.

@tsonic/dotnet is a generated binding package. It gives Tsonic projects an importable TypeScript surface for Microsoft.NETCore.App assemblies while the compiled program still targets the real .NET runtime assemblies.

Install

npm install @tsonic/dotnet @tsonic/core

Use with Tsonic

Default CLR workspaces include the BCL binding package in the normal compiler setup. Import CLR namespaces explicitly:

import { Console } from "@tsonic/dotnet/System.js";
import { List } from "@tsonic/dotnet/System.Collections.Generic.js";
import type { int } from "@tsonic/core/types.js";

export function main(): void {
  const values = new List<int>();
  values.Add(42);
  Console.WriteLine(values.Count.ToString());
}

Package shape

The package exposes one ESM facade per CLR namespace plus compiler metadata:

@tsonic/dotnet/
  System.d.ts
  System.js
  System/
    bindings.json
    internal/index.d.ts
  System.Collections.Generic.d.ts
  System.Collections.Generic.js
  System.Collections.Generic/
    bindings.json
    internal/index.d.ts
  __internal/extensions/index.d.ts
  families.json

• <Namespace>.d.ts is the public import facade.
• <Namespace>.js is an ESM stub for package resolution.
• <Namespace>/internal/index.d.ts contains the full generated declaration surface.
• <Namespace>/bindings.json carries CLR identity, overload, receiver, extension, nullable, and generic metadata for the Tsonic compiler.
• __internal/extensions/index.d.ts contains generated extension-method wrapper types used for C#-style using semantics.
• families.json records multi-arity type families such as Func, Action, and ValueTuple.

Type model

• CLR type and member names are emitted with CLR-faithful casing.
• CLR primitives use @tsonic/core/types.js aliases such as int, long, double, bool, and char.
• Generic CLR names keep their arity-safe declarations, with facade aliases for common families.
• Delegates emit callable TypeScript types.
• Task and ValueTask are thenable in TypeScript positions.
• Extension methods are available through generated ExtensionMethods helpers.

Example extension-method wrapper:

import type { ExtensionMethods as Linq } from "@tsonic/dotnet/System.Linq.js";
import type { IEnumerable } from "@tsonic/dotnet/System.Collections.Generic.js";
import type { int } from "@tsonic/core/types.js";

type LinqEnumerable<T> = Linq<IEnumerable<T>>;

declare const values: LinqEnumerable<int>;
const positive = values.Where((value) => value > 0);

Versioning

This repo is versioned by .NET major:

• .NET 10 declarations live under versions/10/.
• The npm package is published as @tsonic/[email protected].

Development

Regenerate the .NET 10 package from a sibling tsbindgen checkout:

npm install
npm run generate:10

The generation script requires:

• .NET 10 SDK/runtime
• ../tsbindgen
• a Microsoft.NETCore.App runtime directory selected by DOTNET_HOME and DOTNET_VERSION

Example for a system install:

DOTNET_HOME=/usr/lib/dotnet DOTNET_VERSION=10.0.5 npm run generate:10

License

MIT