@netlify/build/lib/plugins/child/lazy.js

Netlify build module

import memoizeOne from 'memoize-one';
// Add a `object[propName]` whose value is the return value of `getFunc()`, but
// is only retrieved when accessed.
export const addLazyProp = function (object, propName, getFunc) {
    const mGetFunc = memoizeOne(getFunc, returnTrue);
    // Mutation is required due to the usage of `Object.defineProperty()`
    Object.defineProperty(object, propName, {
        get: mGetFunc,
        enumerable: true,
        configurable: true,
    });
};
const returnTrue = function () {
    return true;
};