multi-extend

Warning: this package has severe limitations and countless failure edge cases due to how the JS class system works.

A utility for extending multiple classes in JavasScript, enabling the creation of mixins.

docs: https://electrovir.github.io/multi-extend/functions/multiExtend.html

Example usage:

class MyClass extends multiExtend(RegExp, URL) {
    constructor() {
        super(['w+'], ['https://example.com']);
    }
}
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This uses Proxy under the hood to ensure maximum ability to use inherited members.

Limitations

• instanceof will not work on constructors passed to multiExtend.

  • Meaning, the following will always be false:

    const baseClass = multiExtend(RegExp, URL);
    class MyClass extends baseClass {}
    
    return new MyClass() instanceof baseClass;
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• Overridden methods will need to be assigned with arrow functions.

  • example:

    class A {
        myMethod() {
            return 'hi';
        }
        myMethod2() {
            return 'hi';
        }
    }
    
    class B {
        myMethod2() {
            return 32;
        }
    }
    
    class ChildClass extends multiExtend(A, B) {
        // this needs an arrow function
        override myMethod = () => {
            return 'hi';
        };
    }
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