How to see log sources from auxiliaryWorkers using Vite plugin?

[nzakas]

I've just upgraded to Astro 6 and I'm using the Vite plugin to load in auxiliaryWorkers. This is all working well.

The problem is that all of the console.log() statements end up output to the same place with no indication of which worker they're coming from, so the logs are all mixed together. I miss wrangler dev telling me which worker the logs are coming from in the console.

Is there a way to enable logs from the auxiliary workers to be output to the terminal with the worker name?

[mg1986jp]

There's no built-in way to label logs per auxiliary worker right now. Miniflare/workerd doesn't tag console.log() output with the worker name when running multiple workers in the same process.

Easiest workaround — create a tagged logger in each worker:

// In your main worker
const log = (...args: unknown[]) => console.log('[main]', ...args);

// In each auxiliary worker
const log = (...args: unknown[]) => console.log('[auth-worker]', ...args);

If you want something less manual, wrap console at the top of each worker's entrypoint:

const WORKER_NAME = 'auth-worker'; // or derive from import.meta.url

const originalConsole = { ...console };
for (const method of ['log', 'warn', 'error', 'info', 'debug'] as const) {
  console[method] = (...args: unknown[]) => originalConsole[method](`[${WORKER_NAME}]`, ...args);
}

This is admittedly not great compared to wrangler dev's old per-worker labeling. Might be worth opening a feature request on the workers-sdk repo for this — the Vite plugin's auxiliaryWorkers integration is still pretty new and log labeling seems like a reasonable ask.

[aicayzer]

Confirming what @mg1986jp said — no built-in flag for this. The vite-plugin runs all the workers in one workerd process and console.log writes straight to the parent stdout with no source attribution. Different to wrangler dev where each worker gets its own process.

Cleanest workaround I've found is monkey-patching console at the top of each worker so you don't have to touch every log call:

// src/main.ts (and similarly in each aux worker)
const TAG = '[main]'; // or [auth], [api], etc.
for (const m of ['log', 'warn', 'error', 'info', 'debug'] as const) {
  const orig = console[m].bind(console);
  console[m] = (...args: unknown[]) => orig(TAG, ...args);
}

One-time setup per worker, all logs auto-tagged after that. Works for transitive ones too (deps that call console.log themselves).

If this is something you'd want first-class in the plugin it'd probably want raising as a feature request on workers-sdk — feels like a reasonable miniflare-level addition (it already names workers in its config).