What should be the canonical file extension for Svelte components?

extensions.md

So far, most of us have been writing Svelte components into .html files, with a few exceptions (Parcel users, for example, have additional constraints to work with). We're currently discussing whether this should change.

Once you've read the pros and cons, please vote!

.html

Pros:

• It signals that you can use your existing HTML (and CSS) knowledge
• Valid HTML is valid Svelte
• Syntax highlighting mostly works everywhere OOTB (expressions in {tags} are treated as text, though)

Cons:

• Svelte components aren't really HTML
• Tools like Parcel can't deal with it
• We don't get full syntax highlighting
• Some tools, like WebStorm, struggle with directives etc

.htmlx

Pros:

• It signals that it's HTML-with-extras
• Symmetry with .js and .jsx
• It's an invitation to other frameworks to collaborate, rather than continuously reinventing template languages

Cons:

• No syntax highlighting out of the box — imposes tooling requirements on users, could be offputting for new recruits
• It's a land grab
• May be hard to get Linguist to adopt Svelte syntax highlighting for it

.svelte

Pros:

• Does what it says on the tin. Zero ambiguity
• Linguist support — we should be able to claim svelte for fenced code blocks
• It's unlikely to cause conflict with other frameworks etc

Cons:

• No syntax highlighting. Like .htmlx, the first-time experience is poor

.svlt is a good name IMO. Ee simply remove the vowels but also maintain the pronunciation to be svelte.

.sv for easier typing. .s is possible but is clashing with assembly.