Last week ECMAScript editor Brian Terlson published a proposal for a couple new Array.prototype methods, namely .flatten and .flatMap. Nicolás Bevacqua walks through each method and talks about it's uses.
A simplified way to generate massive mock data based on a schema, using the awesome fake/random data generators like (FakerJs, ChanceJs, CasualJs and RandExpJs), all in one tool to generate your fake data for testing.
Reduce might be the most potent method on the Array prototype. Unlike map and filter, who only codomain can be arrays, reduce's codomain can be just about anything. Darion Welch dives deep into use cases and examples of using Array.prototype.reduce.