AOT: rest-parameter collection silently drops args inside `@perryts/redis`'s `Connection.command()` (could not minimize)

[proggeramlug]

Summary

Under perry compile, calling conn.command('SET', 'k', 'v') on a @perryts/redis Connection instance reaches the encoder with args.length === 1 (instead of 2), and the single element is a denormal-double (same NaN-box symptom as #653, which fixed the spread-side variant). The bytes sent to Redis are then SET <denormal> → -ERR wrong number of arguments for 'set' command.

Passing the args as an explicit array via commandArray(name, args) — same sendCommand callee, just no rest-collection — works correctly.

I could not minimize the repro outside the driver. Isolated tests with rest + generic + class + private-field + union-type + cross-module imports all collect args correctly. There's something specific to the actual @perryts/redis Connection class's shape that hits this path. Filing anyway because the symptom is reliable in-driver and the workaround indirection shouldn't be necessary.

Environment

• perry 0.5.795
• macOS 26.4 / Apple M1 Max

Reliable in-driver repro

cd /tmp && bun add @perryts/redis
# (or: git clone https://github.com/PerryTS/redis.git; cd redis; bun install)

// repro.ts
import { connect } from '@perryts/redis';

async function main() {
    const conn = await connect({ host: '127.0.0.1', port: 6379, protocol: 2 });

    // Rest form — fails under AOT, works on Node + Bun.
    try {
        const r = await conn.command<string>('SET', 'k', 'v');
        console.log('command(rest):     ', r.value);
    } catch (e: any) { console.log('command(rest) ERR:', e.message); }

    // Explicit-array form — works everywhere.
    const r2 = await conn.commandArray<string>('SET', ['k', 'v']);
    console.log('commandArray:      ', r2.value);

    await conn.close();
    process.exit(0);
}
main();

$ redis-server --port 6379 --daemonize yes --save '' --appendonly no
$ perry compile repro.ts -o repro && ./repro
connected
command(rest) ERR: ERR wrong number of arguments for 'set' command
commandArray:       OK

Node + Bun output (correct on both call shapes):

connected
command(rest):      OK
commandArray:       OK

What Connection.command() looks like

class Connection {
    private readonly id: number;
    // ...
    command<T = unknown>(name: string, ...args: CommandArg[]): Promise<CommandReply<T>> {
        return sendCommand<T>(this.id, name, args);
    }
    commandArray<T = unknown>(name: string, args: CommandArg[]): Promise<CommandReply<T>> {
        return sendCommand<T>(this.id, name, args);
    }
}
type CommandArg = string | Buffer | number | bigint;

The two methods differ only by ...args vs args. Same callee, same Promise shape. The rest form drops args under AOT; the array form doesn't.

Things I tried that did NOT reproduce

• Generic async method with rest + union type + class + cross-module import (worked).
• Same with a private numeric field on the class (worked).
• Multi-level pass-through of the rest-collected array through three function calls (worked).
• Class method with Map<number, State> lookup using the id field (worked).

So the trigger is something cumulative in the actual Connection class — possibly the number of other methods, interaction with the imports at the top of src/connection.ts (it imports from ./protocol/reader, ./protocol/writer, ./protocol/types, ./transport/net-socket, etc.), or interaction with the side-effect imports (./register-defaults, ./auth/handshake-hook). I'd be happy to bisect if you can suggest where to look.

Related

• AOT: spread of non-empty typed array passes denormal placeholders to callee #653 — spread of non-empty array → 5e-324 (fixed in 0.5.795). Same NaN-box symptom on the spread side; this is the receive side.

Workaround in @perryts/redis

Added commandArray(name, args) and pipeline.addArray(name, args) companions to the rest-form methods. Bun and Node ignore the indirection; AOT users have to call the array form until this is fixed.