HGET can return null, but TypeScript says it can't

[lantw44]

Description

Run the example code:

import { createClient, RedisClientOptions } from 'redis';

const options: RedisClientOptions = {};
const client = await createClient(options)
  .on('error', err => console.log('Redis Client Error', err))
  .connect();

const value = await client.HGET('hash', 'key');
console.log(value);

await client.disconnect();

It prints null if hash doesn't exist on the server. However, TypeScript says:

┌─────────────────────────────────────────────────┐
│const value: string | undefined                  │
└─────────────────────────────────────────────────┘

Which is wrong. TypeScript should remind the caller it should handle null.

Node.js Version

20.12.2

Redis Server Version

7.0.7 (Amazon ElastiCache)

Node Redis Version

4.7.0

Platform

Linux

Logs

No response

[leibale]

Oops... 🤦
To fix it we should change the HGET transformReply function type to return RedisCommandArgument | null rather than RedisCommandArgument | undefined.

LMK if you want to create a PR, or if you prefer that I'll do that..

[aarifkhan7]

Hey @leibale, I am new to the community and working on good first issues, can I create a PR for this?

[MManke188]

This is also true for hmGet, which at the moment is annotated as returning an array of strings, but it can also contain null values

[aarifkhan7]

This issue is now fixed as per the latest version of the file see here. Both hget and hmget is of appropriate type now, we can move with closing this issue.