feat: improve compile error reporting

[dominikg]

convert compiler error to a RollupError that is displayed to the user in a more friendly way than the current stack pointing into vite-plugin-svelte.

This is a bit verbose and causes messages to be sent multiple times on console for sveltekit (ssr and regular compile) but at least it's showing the correct file and frame.

fixes #218

[dominikg]

@benmccann please try it and let me know if that's good enough. We may be able to improve this further by additional handling in kit itself.

[benmccann]

I think this line needs to be updated as well:

vite-plugin-svelte/packages/vite-plugin-svelte/src/utils/esbuild.ts

Line 91 in aadb92d

const compiled = compile(finalCode, finalCompileOptions) as Compiled;

Besides that, lgtm.

We may be able to improve this further by additional handling in kit itself.

I'm curious what we might do on the kit side?

[dominikg]

compile errors are handled for esbuild now too (differently than for vite because it has a different reporting format).

Should we add similar try/catch to svelte.preprocess ? the way i added try/catch both preprocess and compile errors are already caught 😵‍💫

[dominikg]

i'm having a hard time provoking an error that triggers the esbuild error handling changed in this PR.

[dominikg]

finally was able to trigger it thanks to @bluwy .

this is how esbuild prebundling errors will be displayed (cli only)

> e2e-tests-configfile-esm@1.0.0 dev /home/dominikg/develop/sveltejs/vite-plugin-svelte/packages/e2e-tests/configfile-esm
> vite

 > ../_test_dependencies/svelte-src-export/src/components/Dependency.svelte:3:5: error: [plugin: vite-plugin-svelte:optimize-svelte] /home/dominikg/develop/sveltejs/vite-plugin-svelte/packages/e2e-tests/_test_dependencies/svelte-src-export/src/components/Dependency.svelte:3:5 Unexpected token
     3 │  foo(;
       ╵      ^
   html:/home/dominikg/develop/sveltejs/vite-plugin-svelte/packages/e2e-tests/configfile-esm/src/App.svelte:23:23: note: The plugin "vite-plugin-svelte:optimize-svelte" was triggered by this import
    23 │ import Dependency from 'e2e-test-dep-svelte-src-export/src/components/Dependency.svelte';
       ╵                        ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

The link to the file with the error is clickable in intellij idea (and i hope in vscode too)

These esbuild errors should be rare though as the .svelte files are published in a library and hopefully the library maintainers are thoughtful enough to not publish erroneous .svelte files.
Theoretically preprocessor or compiler errors/breaking changes could trigger this for valid .svelte files, but in that case i'd expect a lot more errors everywhere in the project.

vite devserver cli shows this

3:37:14 PM [vite] Internal server error: /home/dominikg/develop/sveltejs/vite-plugin-svelte/packages/playground/kit-demo-app/src/lib/Counter/index.svelte:14:5 Unexpected token
  Plugin: vite-plugin-svelte
  File: /home/dominikg/develop/sveltejs/vite-plugin-svelte/packages/playground/kit-demo-app/src/lib/Counter/index.svelte
   12 |      return ((n % m) + m) % m;
   13 |    }
   14 |    foo(;
               ^
   15 |  </script>
   16 |  

and the overlay looks like this

[bluwy]

Some format nitpicks