finally!

Following up on this, this suggests that the new stuff of ES2018 is, yes, a spread operator, asynchronous iteration (which is what it sounds like), and, among other things a .finally to go with the .then and the .catch of a promise. This suggests in ES2019 we get Array.flat() for flattening a multidimensional array to a single dimension and both String.trimStart() and String.trimEnd() too which do what you think.