Plugin-ext only can use one plugin at the same time

[misakajimmy]

Bug Description:

Theia frontend plugin can start one at the same time.

Steps to Reproduce:

1. Use yo generate two frontend hello-world example plugin in the same dir
2. Start theia with --plugins=local-dir:path/to/dir
3. Theia successful load two plugin but only one plugin Started plugin,the second plugin will be overwrited

There seems a bug here

https://github.com/eclipse-theia/theia/blob/master/packages/plugin-ext/src/hosted/browser/hosted-plugin.ts#:~:text=const%20host%20%3D%20plugin,set(host%2C%20dynamicContributions)%3B

                const host = plugin.model.entryPoint.frontend ? 'frontend' : plugin.host;
                const dynamicContributions = hostContributions.get(plugin.host) || [];
                dynamicContributions.push(contributions);
                hostContributions.set(host, dynamicContributions);

if two plugins all frontend plugins,at first plugin load host = "frontend", plugin.host = "main", dynamicContributions = hostContributions.get("main"),
but dynamicContributions which load from main will set to host which is frontend .
when load second plugin, dynamicContributions will load from main and it will lead to dynamicContributions = [], i think it should load from forntend,Otherwise first plugin will be overwrite

Additional Information

• Theia Version: since 1.13.0

[vince-fugnitto]

@misakajimmy I believe it is a duplicate of #9064, I'll close the other issue as you already attempted a fix 👍

[tsmaeder]

@misakajimmy do you have an interesting use case for front-end plugins you could share?