Oh-My-Patch

Oh-My-Patch is an advanced function and property patcher for JavaScript and TypeScript. It allows you to monkey-patch functions and accessors safely, track metadata, scope patches, and even profile execution time.

Features

• Patch functions or object properties dynamically
• Support for both value properties and accessors (get/set)
• Scope-based patching for safe temporary changes
• Profile execution (call count and total time)
• Undo patches selectively or globally
• Works with JavaScript and TypeScript

Installation

npm install ohmypatch

Usage

Patch a function

import { patch, unpatch } from 'ohmypatch';

function greet(name: string) {
  return `Hello, ${name}`;
}

// Apply a patch
patch({ greet }, 'greet', (name: string) => `Hi, ${name}`);

console.log(greet('Alice')); // Hi, Alice

// Undo the patch
unpatch({ greet }, 'greet');

console.log(greet('Alice')); // Hello, Alice

Patch an accessor

const obj = {
  get value() {
    return 42;
  }
};

patch(obj, 'value', {
  get: () => 100,
  set: (v) => console.log('Trying to set:', v)
});

console.log(obj.value); // 100
obj.value = 200;        // Trying to set: 200

Scoped patch execution

import { withPatch } from 'ohmypatch';

withPatch(() => {
  patch(obj, 'value', { get: () => 500 });
  console.log(obj.value); // 500
});

// Patch automatically removed after scope ends
console.log(obj.value); // 42

List active patches

import { listPatches } from 'ohmypatch';

console.log(listPatches());

License

This project is licensed under the Apache-2.0 License.