tscm

Function-like macros for TypeScript, inspired by Rust

• Fully type-checked
• IDE support - correct messages, types and diagnostics while editing
• easy to use, easy to write
• Generates correct source-maps
• Compatible Babel plugin

For a collection of example macros, like GraphQL or SQL, see the tscm-examples repository.

Installation

Bring your own TypeScript, version 4.0 or higher

# Yarn
yarn add -D tscm typescript

# npm
npm install -D tscm typescript

Example

Usage

// macros are imported like normal
import { macro } from './macros';

// Two non-null-assertion operators are used as indicator for macro calls
const val = macro!!('literal', identifier);

Macro definition

Macros are normal functions that get the CallExpression Node as parameter and return a new Node. They can be local files or npm packages. For more information see the Writing macros guide.

const t = require('@babel/types');

/**
 * @type {import('tscm/macro').Macro}
 */
module.exports.macro = function ({ node }) {
  // Returns that arguments as an array
  return t.arrayExpression(node.arguments);
};

Compiling

To compile, use tscm instead of tsc. If you are using a bundler, see Bundler setup.

npx tscm

Editor config

To get the correct types in your editor, make sure to point it to tscm.

coc.nvim

// .vim/coc-settings.json
{
  "tsserver.ignoreLocalTsserver": true,
  "tsserver.tsdk": "./node_modules/tscm/typescript/lib"
}

VS Code

Make sure to select Use Workspace Version under TypeScript: Select TypeScript version

// .vscode/settings.json
{
  "typescript.tsdk": "./node_modules/tscm/typescript/lib"
}

Documentation

1. Bundler setup
2. Writing macros
3. How it works