Chunked execution of async functions

chunkedExecution.js

/**
 * Serially executes a promise returning function over an array of inputs, 
 * Each time waiting for {chunkSize} inputs execution to resolve before 
 * executing fn over the next inputs chunk.
 * @param {A promise returning function} fn 
 * @param {Number} chunkSize 
 * @param {An array where each item is an input to fn} inputs 
 */
function chunkedExecution(fn, chunkSize, inputs) {
  const chunks = R.splitEvery(chunkSize, inputs);
  return chunks.reduce(
    (p, chunk) => p.then(() => Promise.all(chunk.map(fn))),
    Promise.resolve()
  );
}