ToBinding crashes on null service handle during unsubscribe/shutdown

[hubyrod]

Summary

ToBinding.SkipRuntime_ServiceDefinition__unsubscribe and SkipRuntime_ServiceDefinition__shutdown in @skipruntime/core crash with a TypeError when this.handles.get(skservice) returns undefined.

Additionally, abortFork() can throw inside a catch block, swallowing the original exception.

Location

@skipruntime/core — dist/src/index.js, class ToBinding (around line 792+)

How to reproduce

1. Start a Skip service with a Postgres external service
2. Trigger a scenario where the service handle is cleaned up before unsubscribe or shutdown is called (e.g. a connection error or rapid restart)
3. The runtime crashes with TypeError: Cannot read properties of undefined (reading 'unsubscribe') or (reading 'shutdown')

For the abortFork issue:

1. Trigger a fork initialization failure (e.g. the external service errors during subscribe)
2. The catch block calls this.abortFork() which itself throws
3. The original error is lost; only the cleanup error propagates

Expected behavior

• unsubscribe should be a no-op if the service handle no longer exists
• shutdown should resolve gracefully if the service handle no longer exists
• abortFork() failures during error cleanup should not mask the original exception

Workaround

// unsubscribe — add null guard
SkipRuntime_ServiceDefinition__unsubscribe(skservice, external, instance) {
    const service = this.handles.get(skservice);
    if (service == null) return;
    service.unsubscribe(external, instance);
}

// shutdown — add null guard, return resolved promise
SkipRuntime_ServiceDefinition__shutdown(skservice) {
    const service = this.handles.get(skservice);
    if (service == null) return this.handles.register(Promise.resolve());
    return this.handles.register(service.shutdown());
}

// abortFork — wrap in try-catch
catch (ex) {
    this.setFork(uuid);
    try { this.abortFork(); } catch (_) { /* cleanup failure, ignore */ }
    throw ex;
}

Version

@skipruntime/core@0.0.19