Easily make one function imitate or mimic the properties and behaviors of another while preserving its identity.

Installation

Install via npm:

npm install function-imitator

Usage

import { imitate } from 'function-imitator';

function original() {
    console.log('This is the original function');
}

function imitator() {
    console.log('This is the imitator function');
}

// Make `imitator` mimic `original`
imitate(imitator, original);

// Calling `imitator` now behaves like `original`
imitator(); // Outputs: "This is the original function"

Options

The imitate function accepts an optional third argument for configuration:

• ignoreNonConfigurable (default: false): If set to true, the function won't attempt to copy non-configurable properties from the source to the target function.

Example:

imitate(to, from, { ignoreNonConfigurable: true });

Rationale

There are scenarios where you might want to replace a function with another (e.g., for mocking, extending behaviors, or A/B testing) but still want to preserve some of the original function's identity and characteristics. This utility facilitates that.

Limitations

1. Protected properties like length, prototype, arguments, and caller are not copied from the source function.
2. Functions being passed should not be arrow functions, as they do not have properties like prototype.

License

MIT