Not sure what to think of summary "articles" like this. I'm not a fan of them, even though they can open your eyes to something you may not have seen before.
Aside: just not a fan of angular in general.
I'd really like to see articles like this using fetch api[1] directly over axios. It's not that Axios doesn't work, but it's over 12kb (4.3kb min+gz)[2] .. you could do every call long form with fetch for less, you can do better still with a custom simple wrapper around it.
[1] https://caniuse.com/#feat=fetch
[2] https://bundlephobia.com/result?p=axios@0.19.0
These are pretty much the only features I'm still using Babel for… pretty much everything else is already in modern browsers and the current/latest Node.
Seems like the optional chaining operator has sat in limbo forever, recently moved to stage 3 iirc.
Another one is the pipeline operator. I'm hoping the F# syntax wins in the end.
One thing to consider as a second pass, would be to wrap this in a pool or queue that returns promises. capture the worker, a resolve/reject and the on handlers use the captured handlers or throw.
This way you can do expensive processors as a limited pool of workers. I've done similar to this with separate child_processes before.
One piece not covered is bitwise shift, which is useful for setting flags in a clear way, for example.
const LIST_FRACTION = 1 << 0; // (001)
const LIST_UNIQUE = 1 << 1; // (010)
const LIST_SORTED = 1 << 2; // (100)
Beyond that, you don't need to check against the flag, since a match will be non-zero (truthy)
if (flag & LIST_UNIQUE) {}
I use Lighthouse built into chrome, but also use the WAVE and AXE extensions as well... they each have advantages/disadvantages over each other, with maybe 80% overlap.
One piece not covered is bitwise shift, which is useful for setting flags in a clear way, for example. const LIST_FRACTION = 1 << 0; // (001) const LIST_UNIQUE = 1 << 1; // (010) const LIST_SORTED = 1 << 2; // (100) Beyond that, you don't need to check against the flag, since a match will be non-zero (truthy) if (flag & LIST_UNIQUE) {}