ioredisAdapter: set() with options loses this, so setOnlyIfNotExists always throws a TypeError #255

Preflight checklist

• I searched existing issues and didn't find a duplicate.
• This is a bug report, not a usage question.

@fortedigital/nextjs-cache-handler version

3.4.0 (packages/nextjs-cache-handler/src/helpers/ioredisAdapter.ts on master has the same code)

Next.js version

Not relevant: the script below reproduces it with only this package, ioredis and a Redis server. We hit it in a Next.js 16.4.3 production app that uses registerInitialCache.

Summary

When the ioredisAdapter proxy's set is called with an options object, it takes target.set out of the ioredis client and calls it detached:

const setFn = target.set;
return setFn(key, value, ...extraArgs);

ioredis' set relies on this, so the call throws TypeError: Cannot read properties of undefined (reading 'options'). Through createRedisHandler this means ctx.setOnlyIfNotExists: true (the non-destructive hydration path added in #181) always throws when the client is wrapped with ioredisAdapter, so registerInitialCache({ setOnlyIfNotExists: true }) cannot be used with ioredis.

Steps to reproduce

import Redis from "ioredis";
import { ioredisAdapter } from "@fortedigital/nextjs-cache-handler/helpers/ioredisAdapter";
import createRedisHandler from "@fortedigital/nextjs-cache-handler/redis-strings";

const client = new Redis("redis://127.0.0.1:6379");
if (client.status !== "ready") await new Promise((r) => client.once("ready", r));

const handler = createRedisHandler({ client: ioredisAdapter(client), keyPrefix: "t:" });
const entry = (body) => ({
  value: { kind: "FETCH", data: { headers: {}, body } },
  tags: [],
  lastModified: Date.now(),
  lifespan: { expireAt: Math.floor(Date.now() / 1000) + 600 },
});

await handler.set("k1", entry("x"), {});                            // ok
await handler.set("k2", entry("x"), { setOnlyIfNotExists: true });  // TypeError

Expected vs. actual behavior

Expected: the second call stores k2 only if it does not exist yet (SET ... NX), as it does with the node-redis client.

Actual: TypeError: Cannot read properties of undefined (reading 'options').

What I measured (ioredis 5.11.1, Node 24.19.0, Redis server 8.10.1):

I did not look into why the plain and EXAT-only handler.set paths work in my run while the adapter's set throws for EXAT when called directly.

Changing that one line to const setFn = target.set.bind(target); (on a copy of the 3.4.0 file) makes the handler call succeed, and the second setOnlyIfNotExists write does not overwrite the first one (checked against a real Redis).

Router / caching mode in use

App Router + Cache Components (PPR) in our app; the reproduction above does not involve Next.js.

Which handler(s) from this package are configured?

redis-strings via ioredisAdapter

Redis / ioredis / Node.js versions

ioredis 5.11.1, Redis server 8.10.1, Node 24.19.0

Deployment topology

Not relevant to the reproduction (single process, one Redis).

Does this reproduce on the unmodified examples/redis-minimal app?

Haven't tried. The script above exercises only this package, ioredis and Redis.

Contribution

I have not opened a pull request. Before I do: is setOnlyIfNotExists meant to be supported through ioredisAdapter? If so, would you take a PR with the one-line change plus a regression test, and is the isolated Redis e2e suite from #240 the right place for it?