Plugins using environment references

[jasonkuhrt]

Environment Instance Stability During Dev Server Lifecycle

Context

I'm developing a Vite plugin that needs to track which environments load a virtual module and invalidate the module in those specific environments when the underlying data changes.

Current Implementation

Currently storing environment names and looking them up dynamically:

const envNamesLoaded = new Set<string>()

// In load hook:
envNamesLoaded.add(this.environment.name)

// For invalidation:
for (const envName of envNamesLoaded) {
  const env = $server.environments[envName]
  if (env && env.moduleGraph) {
    // invalidate...
  }
}

Question

Would it be safe to store direct references to Environment objects instead?

const environmentsLoaded = new Set<Environment>()

// In load hook:
environmentsLoaded.add(this.environment)

// For invalidation:
for (const env of environmentsLoaded) {
  // invalidate directly...
}

Specific concerns:

1. Are Environment instances stable throughout the dev server lifecycle?
2. Can environments be recreated/replaced during runtime (e.g., config changes, HMR)?
3. Would storing references prevent garbage collection or cause stale reference issues?
4. Is dynamic lookup via server.environments[name] the recommended approach?

Use Case

This is for a reactive data plugin that serves virtual modules containing reactive data (using Vue reactivity). When the data changes, we need to invalidate the module in all environments that have loaded it.

Thanks for any guidance on the intended lifecycle and stability guarantees of Environment instances!