fix: properly remove event listeners in Component's removeEventListener (v4)

[ovx]

• fix: properly remove event listeners in Component's removeEventListener

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[ovx]

The event listeners are not properly removed when using removeEventListener for custom events. The method addEventListener adds a listener to the internal this.$$l map but the method removeEventListener does not remove them.

The issue is painfully obvious when using a WebComponent (built form a Svelte component) in React with strict mode enabled, where the component is mounted twice resulting in the listener being attached twice without the first one being removed.

Example:

const button = document.querySelector('my-button');

const handler = () => {
  console.log('myaction handler');
};

// add and remove, simulating React's strict mode
button.addEventListener('myaction', handler);
button.removeEventListener('myaction', handler);

// only add
button.addEventListener('myaction', handler);

The code above does not remove the first listener, firing the handler twice.

[dominikg]

@ovx

it looks like you published copies of svelte and vite-plugin-svelte to the public npm registry, keeping the original metadata for repository and license etc. in place. This can be confusing for both users and tools (eg github now shows your plugin as first if you look up the dependents of vite-plugin-svelte https://github.com/sveltejs/vite-plugin-svelte/network/dependents)

Please remove/make them private or update all metadata to make it clear they are not provided by the svelte org but forks.