TypeError: Cannot read properties of undefined (reading '$$') when using 0.42.0 or newer

[Trystan-SA]

When I'm using any components from carbon-components-svelte. It trigger the following error :

Here is the code that trigger the error. It happen when I'm using any components (buttons, forms, accordions):

I don't have this issue if I'm using the 0.41.0 version. It start breaking at 0.42.0 or newer.

My package versions :
svelte: 3.44.1
esbuild: 0.13.12
esbuild-svelte: 0.5.7 (and tested with 0.5.3 too)

[ulvido]

same environment and same error for me too.
in my case, I send a component with a javascripts general Custom Event and catch the event at another place.

The error occurs if you want to render a received component with svelte:component

EXAMPLE CODE

create a custom event and dispatch at some far place

...

const register = new CustomEvent(
  "REGISTER_APP",
  {
    bubbles: true,
    detail: {
      mycomponent: SomeSvelteComponent,
    },
  }
)

window.dispatchEvent(register);

catch the custom event at store

...

export const customComponent = writable(undefined)

window.addEventListener("REGISTER_APP", e => {
  customComponent.set(e.detail.mycomponent)
});

...

use component

...

import { customComponent } from "./store"

<div>
  {#if $customComponent}
     <svelte:component this={$customComponent} />
  {/if}
</div>

...

something fails when setting the component but what that I dont know yet.

[onelesd]

Can confirm the same error with v0.42.0 or higher. My env:

svelte: 3.44.1
esbuild: 0.14.8
esbuild-svelte: 0.6.0

[metonym]

I recall experiencing a similar error when using a Svelte library that ships bundled ESM code in addition to uncompiled Svelte source files.

Just a hunch, but I wonder if it is trying to use the bundled Carbon Svelte library instead of the uncompiled source.

[onelesd]

Related issue: sveltejs/svelte#6584

[metonym]

I was able to repro the error using esbuild + esbuild-svelte + carbon-components-svelte.

I definitely think it's related to esbuild using the compiled source code. When I manually changed the "main" field to point to the uncompiled Svelte source code, it worked.

- "main": "./lib/index.js",
- "module": "./lib/index.mjs",
+ "main": "./src/index.js",

It should be prudent to drop support for the bundled source code, and instead point the "svelte" and "main" fields to the Svelte source code. This practice also seems to be encouraged by svelte-kit package.

[Trystan-SA]

Your PR fixed my issue. Thanks !