pluck.js

export const pluck = (propPath, defaultValue = undefined) => {
    let addr = !Array.isArray(propPath) ? `${propPath}`.split('.') : [...propPath];
    return obj => {
        let target = addr.reduce((res, prop) => (!isNullOrUndefined(res) ? res[prop] : res), obj);
        return target === undefined ? defaultValue : target;
    };
}

sequence.js

/**
 * Run a seriese of pormises in a stack
 */
export const sequence = async (...promiseGenerators) => new Promise(function (resolve, reject) {
    const HEAD = 0;
    const step = async (lastResult, nextFunction, ...rest) => {
        return await (Promise.resolve(nextFunction(lastResult)))
            .then(res => {
                const next = rest[HEAD];
                if (next) return step(res, next, ...rest.slice(HEAD + 1));
                else resolve(res);
            })
            .catch(reject);
    };
    return step(null, promiseGenerators[HEAD], ...promiseGenerators.slice(HEAD + 1));
});

Utility functions

util functions