Object property value resolver

Utility to recursively iterate over an object and use the provided handler to asynchronously resolve/convert property values.

Can be used to allow runtime-resolution of properties for values that cannot be determined when the object is created, via functions, 'macro' strings or any other strategy provided by the handler.

A contrived example may look something like:

const data = {
    first: '#0',
    anArray: ['five','eight','#3'],
    nested: {
        value: '#2'
    },
    dynamic: function(items) {
        // Can return promises here if needed!
        return `The best is ${items[2]}`;
    }
};

function handler(value) {

    let choices = ['one','two','three','four'];

    if (typeof value === 'function') {
        return value(choices);
    }

    if (typeof value === 'string') {
         // Strings starting with a '#' character are treated as 'macros'
         // and will be replaced by the value in the choices array
         // at the specified index.
        if (value.startsWith('#')) {
            const index = value.replace('#','');
            return choices[index];
        }
    }

    return value;
}

resolve(data, handler).then(result => {

    console.log(result);

    // Output:
    // {
    //   first: 'one',
    //   anArray: [ 'five', 'eight', 'four' ],
    //   nested: { value: 'three' },
    //   dynamic: 'The best is three'
    // }

});

Install

Installation using Yarn is recommended.

yarn add @frctl/resolve

Requirements

@frctl/resolve requires Node >= v6.0