Sorting a list of objects in JavaScript

I needed to sort a list of JS objects (in this case representing the data for a post on this blog) by the value of one of the properties of each object (date). Under the hood, each post looks like:

post = {
  slug: "my-slug",
  title: "Post Title",
  date: "2020-05-16",
  author: "Caro Appleby",
  tldr: "words words words",
  tags: ["js", "snippet"],
};

Because the date is in a sensible format, I can just sort the date strings alphabetically. sort() in JS can take a function which tells you how to compare two elements of the list. So my brain goes to a Haskell type signature compareFn :: a -> a -> Int. So you have an array of things of type a, the function gets two of these elements, and the Int you get back tells you which of them should be sorted to a lower index (i.e. come before). If the return value is <0, the first one comes first, if its >0 then the second one comes first.

So, I can sort my array of post objects like:

sortedPosts = posts.sort((a, b) => (a.date < b.date) ? 1 : -1);

if I want them to come back with the newest one first in the array.

Reference blog post and the MDN docs on Array.prototype.sort(). Oh, and the syntax for the ternary operator.