brainbytes/memoize-promise · GitHub

Works just like a normal memoize function. The only difference is that it expects the function you are memoizing to return a promise. Until that promise has resolved/rejected, subsequent calls to the function will return the same promise.

This is useful for instance if you have a function which makes a call to the network. Instead of fetching the same data multiple times, all calls will get the same promise back, allowing for a simple API and efficient use of resources.