Rich Harris - Annoying Things About Svelte

Alright Svelte Loader, it's me Rich with a talk on annoying things about Svelte. This is going to be a two-part talk. The first part is things the Svelte core team has done that annoy you a lot.

This is inspired by a post on the Svelte subreddit last week called what frustrates you in using Svelte. I thought I would just go down as much of this list as time allows and look at some of these points and respond to them. Maybe in some cases explain why we made certain decisions. Maybe in other cases who knows, figure out some to-do list items. The second part is going to be just in the interest of balance and fairness, things that you lot do that annoy the Svelte core team. But we'll get to that. Alright so without further ado, what frustrates you in using Svelte?

That I become sad at work when I have to use Vue instead of Svelte. I'm sorry there's not a lot that we can do about that. Not much honestly, I wish SvelteKit had better error messages when something went wrong. Next had really great debugging compared to SvelteKit. Yeah this is true. We have decent error messages in some cases but not all. I would say that this is kind of a natural phenomenon in software development.

An error occurs when something has gone wrong and the reality is you just kind of anticipate all the ways that something is going to go wrong. Once people start hitting certain cases you might find that you can provide a more informative error message than just throwing whatever error occurred. But in order for that to happen people need to find it. So a framework like Next which has this ginormous user base and has been going for many years. Its users have found all of those situations and raised issues about them.

I think this is one of those things that just kind of naturally gets better over time. We definitely want better error messages in everything that we do. If you hit a situation where you have a cryptic error and you think that the framework could be doing something better then raise an issue because the chances are we'll agree with you. Alright, the VS Code extension, co-completion and formatting often don't do what I expect them to.

Sometimes they completely mess up import statements and I haven't figured out why it works sometimes and sometimes not. I think the VS Code extension is a marvel. Full disclosure I don't totally understand how it works. It's maintained by smarter people than me. I just use it and most of the time I find it works great. It's something that's not 100% perfect but on the whole it works pretty well. But if you do find that you run into cases where stuff isn't working well then you can raise an issue.

All of this stuff is maintained on the language tools repo. So svelte.js language tools. This is where to go. Okay the only things missing from Svelte for me are error boundaries and each over iterables. Yeah so error boundaries, what's meant by that is if an error occurs during rendering it should be possible to recover from that. And at the moment that's not the case in Svelte. You basically need to make sure that errors don't occur during rendering.

This is something that we're definitely thinking about for Svelte for. I don't want to make any strong guarantees but it's something that I want and it's something that lots of other people want. So watch this space. Each over iterables. This is something that's come up from time to time and if you're not familiar with this jargon then it's probably easier if I just show you with a little demo.