babel-remove-types

> [!NOTE]
> This is a fork of https://github.com/cafreeman/remove-types. It's not marked as a fork because we want pull requests to target this repo and not "upstream".

A small library for transforming TypeScript code into JavaScript code in the least destructive way possible. This library exports a single function whose purpose is to preserve everything else about the code except for the actual TypeScript syntax itself. As a result, things like decorators and class fields should pass straight through without being transformed in any way.

Usage

``js
import { removeTypes } from 'babel-remove-types';

const original =
type AnimalType = 'cat' | 'dog';

// An interface for animals (this comment should be removed when transformed)
interface Animal {
type: AnimalType;
name: string;
age: number;
}

class Cat implements Animal {
type: AnimalType = 'cat';
name: string;
age: number;

constructor(name: string, age: number) {
// This is the name of the animal (this comment should stay)
this.name = name;
this.age = age;
}
}
;

console.log(await removeTypes(original));

/*
class Cat {
type = 'cat';

constructor(name, age) {
// This is the name of the animal (this comment should stay)
this.name = name;
this.age = age;
}
}
*/
`

API

$3

- code: A string containing TypeScript code
- prettierConfig:

- defaults to true
- By default, removeTypes will run Prettier with a very basic config on the transformed code before returning it. This allows us to clean up some of the "low-hanging" fruit leftover from the Babel transform, e.g. newlines at the beginning or end of the file.
- If you'd prefer to not run Prettier _at all_, passing false will bypass the Prettier pass entirely.
- If you'd prefer to use your own Prettier configuration, you can pass an object containing Prettier configuration options and removeTypes will use it instead.

- returns Promise`: a string containing the transformed JavaScript output.

Acknowledgements

This library is heavily indebted to cyco130/detype and began as an extraction and refactor of one of its core functions.