svelte:component doesn't work on build mode

[ifraixedes]

Describe the bug

We have a small frontend that used svelte:component directive to render some components dynamically.

In development mode (i.e. npm run dev) the frontend worked perfectly, however, when it's compiled for production (i.e npm run build) it doesn't work.

The frontend doesn't report any error but it doesn't render the dynamic component; it is like if the svelte:component isn't there.

Reproduction

Repository with the specific tag version and the directory where the frontend is that allows reproducing the bug: https://github.com/storj/storj/tree/v1.44.1/satellite/admin/ui

In order to reproduce, you can clone the repository, checkout the commit, and go to the satellite/admin/ui directory.

First, try with npm run dev and then with npm run build and serve the assets with a simple HTTP server (e.g. https://github.com/projectdiscovery/simplehttpserver).

1. Visit the page
2. Enter whatever thing in the input box and press enter or click the confirm button
3. It will appear a select box, select something (e.g. user)
4. It will appear another select box next to the previous one, select something (e.g. get)
5. Some description and input elements will appear below.

While you will see that 5 it's what happens when running in dev mode, it doesn't happen when serving the build assets, only the text will be there but no input element will be rendered.

The component that uses the svelte:component directive is src/UIGenerator.svelte, line 56

Logs

Nothing is reported in the web console in any of the modes (`dev` and `build`).

System Info

The linked repo in that commit contains everything.

Severity

annoyance

[storjBuildBot]

Change https://review.dev.storj.io/c/storj/storj/+/6435 mentions this issue.

[ifraixedes]

The above comment is autogenerated by a bot because I've sent a commit, which mentions this issue, with a workaround until this bug (in case that it's) is fixed.

[kevmodrome]

Can you make a reduced reproduction showing when it breaks? This doesn't sound like an issue with Svelte but more of an error in your application

[Prinzhorn]

constructor.name will not be what you expect, see #6537

[Prinzhorn]

There is no error message because https://svelte.dev/docs#svelte_component

If this is falsy, no component is rendered.

[Conduitry]

👍 As @Prinzhorn indicated, you will either need to rely on something other than the constructor name, or make sure that when you minify things, you tell Terser not to mangle names.

[ifraixedes]

not to mangle names

that's the point that I needed for understanding why it worked in dev and didn't with build, which made me believe that there was a bug in the build process.

Thanks, @Conduitry, and the rest, and my apologies for the noise.

[storjBuildBot]

Change https://review.dev.storj.io/c/storj/storj/+/6439 mentions this issue.