add redis healthcheck

src/health-check.ts

@@ -1,18 +1,35 @@
+import { redisClient } from "./caching";
 import { DatabaseContext } from "./context/database-context";
 
-export const checkHealth = async(dataContext: DatabaseContext): Promise<boolean> => {
+export const checkHealth = async(dataContext: DatabaseContext): Promise<void> => {
   /**
    * Things to check:
-   * - Database connection
-   * - Redis connection
+   * - Database connection (Done)
+   * - Redis connection (Done)
    * - Node connection
    * - Block watcher
    */
+
   const checks = {
-    db: dataContext.checkConnection
+    db: () => dataContext.checkConnection,
+    redis: async() => (await redisClient.mget("test")).length === 1,
   };
 
-  // const healthy = Object.values(checks).every(() => true);
-  // There's no feature in apollo-server-express to return custom error messages, so we leave it empty
-  throw new Error("");
+  const results = await Promise.all(
+    Object.entries(checks).map(async ([key, func]) => ({
+      [key]: await func(),
+    }))
+  );
+
+  let isAnyFailed = false;
+  for(const result of results) {
+    for(const [key, value] of Object.entries(result)) {
+      if(!value) {
+        console.error(`🚫 Health check failed for ${key}`);
+        isAnyFailed = true;
+      }
+    }
+  }
+
+  if(isAnyFailed) throw new Error("Health check failed");
 };