Plugin as sidecar initialization fails when browser is refreshed

[tolusha]

Plugin (run as side car) initialization fails when browser is refreshed.

How to reproduce

• Che 7 workspace with plugin providing command contribution
• Refresh browser
• Observe stack trace in dev console and plugin doesn't work

Error: Command C_Cpp.ConfigurationSelect already exist
    at CommandRegistryImpl.registerCommand (/home/theia/node_modules/@theia/plugin-ext/lib/plugin/command-registry.js:33:19)
    at Object.registerCommand (/home/theia/node_modules/@theia/plugin-ext/lib/plugin/plugin-context.js:101:40)
    at /home/theia/node_modules/@theia/plugin-ext-vscode/lib/node/plugin-vscode-init.js:37:29
    at Array.forEach (<anonymous>)
    at Object.exports.doInitialization (/home/theia/node_modules/@theia/plugin-ext-vscode/lib/node/plugin-vscode-init.js:29:30)
    at Function.PluginHostRPC.initialize (/home/theia/node_modules/@theia/plugin-ext/lib/hosted/node/plugin-host-rpc.js:54:25)
    at Object.init (/home/theia/node_modules/@theia/plugin-ext/lib/hosted/node/plugin-host-rpc.js:95:43)
    at PluginManagerExtImpl.$init (/home/theia/node_modules/@theia/plugin-ext/lib/plugin/plugin-manager.js:85:35)
    at RPCProtocolImpl.doInvokeHandler (/home/theia/node_modules/@theia/plugin-ext/lib/api/rpc-protocol.js:173:23)
    at RPCProtocolImpl.invokeHandler (/home/theia/node_modules/@theia/plugin-ext/lib/api/rpc-protocol.js:158:41)

[tolusha]

/cc @benoitf @evidolob
PluginManagerExtImpl.$init() is invoked every time when browser is refreshed.

[tolusha]

It seems there is no quick fix regarding the root of the issue.
For the time being I propose a workaround:

        if (this.commands.has(command.id)) {
            throw new Error(`Command ${command.id} already exist`);
        }

====>

       if (this.commands.has(command.id)) {
            this.commands.delete(command.id);
            this.proxy.$unregisterCommand(command.id);
            console.warn(`Command ${command.id} already exist and is overridden.`);
        }

Another solution is to postpone until we have a clear vision.

[benoitf]

AFAIK plug-in is being stopped on refresh as well so cleanup of commands should be done at that time (so when it starts again it's not there)

[tolusha]

Make sense, I will check

[tsmaeder]

This is more for the IDE2 team. @evidolob Not a clue what the right approach is here.

[azatsarynnyy]

There's the same issue with the Kubernetes Tooling Plugin.
Running it against Che Theia with Anatoliy's patch fixes the problem.

[benoitf]

should be fixed now with latest fix #4583

[azatsarynnyy]

@benoitf I've tested it with the K8s Plugin. Works well. Thank you!