fix: allow disabling keepAlive in TypeScript

lib/Redis.ts

@@ -227,12 +227,16 @@ class Redis extends Commander implements DataHandledable {
           // Node ignores setKeepAlive before connect, therefore we wait for the event:
           // https://github.com/nodejs/node/issues/31663
           if (typeof options.keepAlive === "number") {
+
+            // prevents TypeScript error when used inside arrow function
+            const { keepAlive } = options;
+
             if (stream.connecting) {
               stream.once(CONNECT_EVENT, () => {
-                stream.setKeepAlive(true, options.keepAlive);
+                stream.setKeepAlive(true, keepAlive);
               });
             } else {
-              stream.setKeepAlive(true, options.keepAlive);
+              stream.setKeepAlive(true, keepAlive);
             }
           }
 

lib/redis/RedisOptions.ts

@@ -28,7 +28,7 @@ export interface CommonRedisOptions extends CommanderOptions {
    * @link https://nodejs.org/api/net.html#socketsetkeepaliveenable-initialdelay
    * @default 0
    */
-  keepAlive?: number;
+  keepAlive?: number | null;
 
   /**
    * Enable/disable the use of Nagle's algorithm.

test/unit/redis.ts

@@ -99,6 +99,9 @@ describe("Redis", () => {
 
         option = getOption("redis://localhost?family=6");
         expect(option).to.have.property("family", 6);
+
+        option = getOption(1234, { keepAlive: null });
+        expect(option).to.have.property('keepAlive', null);
       } catch (err) {
         stub.restore();
         throw err;