chore: help infer the return type of retryKubernetesApiRequest()

We were using "any" as the default return type but we can use generics to help infer the expected response type automatically for us.

Author: ivanstanev

src/supervisor/kuberenetes-api-wrappers.ts

@@ -4,10 +4,11 @@ import * as sleep from 'sleep-promise';
 export const ATTEMPTS_MAX = 3;
 export const DEFAULT_SLEEP_SEC = 1;
 export const MAX_SLEEP_SEC = 5;
-type IKubernetesApiFunction = () => Promise<any>;
-
-export async function retryKubernetesApiRequest(func: IKubernetesApiFunction) {
+type IKubernetesApiFunction<ResponseType> = () => Promise<ResponseType>;
 
+export async function retryKubernetesApiRequest<ResponseType>(
+  func: IKubernetesApiFunction<ResponseType>
+): Promise<ResponseType> {
   for (let attempt = 1; attempt <= ATTEMPTS_MAX; attempt++) {
     try {
       return await func();
@@ -29,6 +30,8 @@ export async function retryKubernetesApiRequest(func: IKubernetesApiFunction) {
       await sleep(sleepSeconds * 1000);
     }
   }
+
+  throw new Error('Could not receive a response from the Kubernetes API');
 }
 
 export function calculateSleepSeconds(httpResponse: http.IncomingMessage): number {