@dudousxd/nestjs-telescope-redis-watcher

Redis command watcher for @dudousxd/nestjs-telescope. Captures every command issued through a wrapped ioredis client and records one redis entry per command ({ command, args, durationMs }), correlated to the request or job that issued it.

Every ioredis command funnels through client.sendCommand(command). The watcher monkey-patches that method on the client instance, captures the command name + args, times the round-trip, and records the entry. The original is always called and its result returned/thrown unchanged — recording failures are swallowed so a telescope error can never alter a command's outcome.

Install

pnpm add @dudousxd/nestjs-telescope-redis-watcher

ioredis is an optional peer dependency — you already have it if your app uses Redis. If the client lacks sendCommand, the watcher no-ops; it never throws.

Usage

Two construction forms are supported.

import { TelescopeModule } from '@dudousxd/nestjs-telescope';
import { RedisCommandWatcher } from '@dudousxd/nestjs-telescope-redis-watcher';

// 1. Wrap a client you already hold:
TelescopeModule.forRoot({
  watchers: [new RedisCommandWatcher(ioredisClient)],
});

// 2. Resolve the client lazily inside register():
TelescopeModule.forRoot({
  watchers: [
    new RedisCommandWatcher({
      instrument: (use, ctx) => {
        use(ctx.moduleRef.get('REDIS_CLIENT', { strict: false }));
      },
    }),
  ],
});

Each captured entry has type redis and RedisContent:

{
  command: string;          // uppercased command name, e.g. 'GET'
  args: unknown[];          // command arguments (redacted by the Recorder)
  durationMs: number | null; // round-trip time, null when unmeasurable
}

Caveat: shared clients

The watcher records exactly what the wrapped client does. If you share one ioredis client with Telescope's own Redis storage provider, those storage commands would be captured too. Pass a dedicated/observed client to the watcher to avoid that noise.

License

MIT © Davi Carvalho