Basic RedisCache implementation

RedisCache.ts

import Redis, { KeyType, Ok } from 'ioredis';

const redis = new Redis(process.env.REDIS_HOST);

export const set = async (
  key: KeyType,
  seconds: number,
  value: Record<string, unknown>,
): Promise<Ok> =>
  // https://redis.io/commands/psetex
  // Set key to hold the string value and set key to timeout
  redis.setex(key, seconds, JSON.stringify(value));

export const get = async <T extends Record<string, unknown>>(
  key: KeyType,
): Promise<T | null> => {
  const value = await redis.get(key);

  if (!value) {
    return value;
  }

  try {
    return JSON.parse(value);
  } catch (err) {
    return value;
  }
};

RedisCacheUsage.ts

import * as RedisCache from './RedisCache';

const fetchWithCache = (url, options, cacheKey, ttl) => {
  const cached = await RedisCache.get(cacheKey);

  if (cached) { return cached; }

  const response = await fetch(url, options);

  if (response.ok) {
    const data = await response.json();

    if (data) {
       // save to redis cache
       await RedisCache.set(cacheKey, ttl, data);
    }
  }

  const text = await response.text();
  return text;
}