Feature/change the redis nodejs library

nodejs/average.js

@@ -1,46 +1,47 @@
-import constants from './constants.js'
-import { Database } from 'sqlite'
-import Redis from 'ioredis'
+import constants from './constants.js';
+import { Database } from 'sqlite';
+import { createClient } from 'redis';
 
-const db = new Database(constants.sqlite_database)
-const redis = new Redis(constants.redis)
+const db = new Database(constants.sqlite_database);
+const client = createClient({ url: constants.redis });
 
 const tavg_average_sql = `SELECT AVG(tavg)
                           FROM weather_measurements
                           WHERE date
-                          BETWEEN (?) AND (?)`
+                          BETWEEN (?) AND (?)`;
 
-/* Returns average of recorded daily temperature from the database. */
 const getAverage = async (location, startDate, endDate) => {
   /* Dynamically generate the cache key */
   const cacheKey = `weather:${location}:${startDate}:${endDate}:average`
 
+  client.on('error', (error) => {
+    throw new Error(error);
+  });
+  await client.connect();
   /* Check Redis for cached entry first */
-  let cacheEntry =  await redis.get(cacheKey)
+  let cacheEntry = await client.get(cacheKey)
 
-  /* If Redis returns a cache hit, */
   if (cacheEntry) {
-    cacheEntry = JSON.parse(cacheEntry)
+    cacheEntry = JSON.parse(cacheEntry);
 
     /* return the entry */
-    return { ...cacheEntry, source : 'cache'}
+    return { ...cacheEntry, source: 'cache' };
   }
 
   /* If Redis returns a cache miss, fetch the entry from the database */
-  await db.open()
-  const dbEntry = await db.get(tavg_average_sql, [startDate, endDate])
+  await db.open();
+  const dbEntry = await db.get(tavg_average_sql, [startDate, endDate]);
 
   /* Add the entry we pulled from the database to the cache */
-  redis.set(cacheKey, JSON.stringify(dbEntry), 'EX', 60 * 60 * 24)
+  client.set(cacheKey, JSON.stringify(dbEntry), { EX: 60 * 60 * 24 });
 
   /* Return the database entry */
-  return { ...dbEntry, source : 'database'}
+  return { ...dbEntry, source: 'database' };
 }
 
 const t0 = new Date().getTime()
 const average = await getAverage('Iceland', '2010-01-01', '2020-11-01')
 const t1 = new Date().getTime()
-average.responseTime = `${t1-t0}ms`
+average.responseTime = `${t1 - t0}ms`
 console.log(average)
-redis.quit()
-process.exit()
+client.quit();

nodejs/constants.js

@@ -1,13 +1,10 @@
 import sqlite3 from 'sqlite3'
 
 export default {
-    'redis' : {
-        'port': process.env.REDIS_PORT || 6379,
-        'host': process.env.REDIS_HOST || '127.0.0.1'
-    },
+    'redis' : `redis://localhost:6379`,
     'sqlite_database': process.env.SQLITE_DB || {
         filename: 'db/weather.db',
         driver: sqlite3.Database
     },
     'weather_csv': process.env.WEATHER_CSV || './db/weather.csv'
-}
+}