ts-generics-macro

This is a Source Transformer that allows you to create function macros in TypeScript. It is designed for use with ts-patch.

This package is inspired by ts-macros. While ts-macros is a great tool, it appears to be currently unmaintained (no commits for over 2 years and inactive on issues/PRs), which has left some instability around generics unresolved.

This project aims to provide a focused alternative specifically for fundamental function macros, prioritizing stability around generics.

Usage

1. Configuration

Add it to your tsconfig.json:

{
  "compilerOptions": {
    "plugins": [
      {"transform": "@ondeoma/ts-generics-macro"}
    ]
  }
}

2. Writing Macros

In your code:

// Define your macro function.
// By default, functions ending with "$macro$" are treated as macros.
function add$macro$(
  a: number,
  b: number,
): number {
  return a + b;
}

// Use the macro.
console.log(add$macro$(1, 2));

Transformed result:

// using macro.
console.log(
  (function (
    a: number,
    b: number,
  ): number {
    return a + b;
  })(1, 2)
);

The macro call is expanded inline, wrapping the body.

You can check package/test-fixtures for more examples of source codes and their expected transformed outputs.

Options

• macroSuffix: The function name suffix used to identify macros. Default is $macro$.

Notes

Standard Source Transformers do not automatically update the TypeChecker after modifying the AST. Since this transformer relies on the TypeChecker (and modifies the AST itself), chaining it with other transformers may lead to stale type information.

To ensure the TypeChecker remains up-to-date throughout the transformation pipeline, consider using ts-rebuild to rebuild the program where necessary.