feat: 🎸 handle -ASK redirects

src/cluster/RedisCluster.ts

@@ -6,7 +6,7 @@ import {PartialExcept, RedisClientCodecOpts} from '../types';
 import {RedisClusterRouter} from './RedisClusterRouter';
 import {RedisClusterNode} from './RedisClusterNode';
 import {RedisClusterCall} from './RedisClusterCall';
-import {isMovedError, parseMovedError} from './errors';
+import {isAskError, isMovedError, parseMovedError} from './errors';
 import {RedisClusterNodeClient, RedisClusterNodeClientOpts} from './RedisClusterNodeClient';
 import {RedirectType} from './constants';
 import {withTimeout} from '../util/timeout';
@@ -270,8 +270,12 @@ export class RedisCluster implements Printable {
         const nextClient = await this.getRedirectClient(host, port, client);
         const next = RedisClusterCall.redirect(call, nextClient, RedirectType.MOVED);
         return await this.__call(next);
+      } else if (isAskError(error)) {
+        const next = RedisClusterCall.retry(call, client);
+        const delay = 50 * 2 ** (next.retry - 1);
+        await new Promise((resolve) => setTimeout(resolve, delay));
+        return await this.__call(next);
       }
-      // TODO: Handle ASK redirection.
       throw error;
     }
   }

src/cluster/RedisClusterCall.ts

@@ -6,20 +6,35 @@ import type {RedisClusterNodeClient} from "./RedisClusterNodeClient";
  * Represents a single Redis request/response command call.
  */
 export class RedisClusterCall extends RedisCall {
-  public static redirect(call: RedisClusterCall, client: RedisClusterNodeClient, type: RedirectType): RedisClusterCall {
+  public static chain(call: RedisClusterCall, client: RedisClusterNodeClient): RedisClusterCall {
     const next = new RedisClusterCall(call.args);
     // next.prev = call;
     next.client = client;
-    next.redirect = type;
-    next.redirects = call.redirects + 1;
+    next.redirects = call.redirects;
     next.maxRedirects = call.maxRedirects;
-    if (next.redirects > next.maxRedirects) throw new Error('MAX_REDIRECTS');
+    next.retry = call.retry;
+    next.maxRetries = call.maxRetries;
     next.utf8Res = call.utf8Res;
     next.noRes = call.noRes;
     next.key = call.key;
     return next;
   }
 
+  public static redirect(call: RedisClusterCall, client: RedisClusterNodeClient, type: RedirectType): RedisClusterCall {
+    const next = RedisClusterCall.chain(call, client);
+    // next.redirect = type;
+    next.redirects = call.redirects + 1;
+    if (next.redirects > next.maxRedirects) throw new Error('MAX_REDIRECTS');
+    return next;
+  }
+
+  public static retry(call: RedisClusterCall, client: RedisClusterNodeClient): RedisClusterCall {
+    const next = RedisClusterCall.chain(call, client);
+    next.retry = call.retry + 1;
+    if (next.retry > next.maxRetries) throw new Error('MAX_RETRIES');
+    return next;
+  }
+
   /**
    * Key to use for routing the command to the correct node.
    */
@@ -28,7 +43,7 @@ export class RedisClusterCall extends RedisCall {
   /**
    * Type of redirect of this call.
    */
-  public redirect: RedirectType = RedirectType.NONE;
+  // public redirect: RedirectType = RedirectType.NONE;
 
   /**
    * Number of redirects that have been performed for this command.
@@ -40,6 +55,16 @@ export class RedisClusterCall extends RedisCall {
    */
   public maxRedirects: number = 4;
 
+  /**
+   * Number of times this command has been retried.
+   */
+  public retry: number = 0;
+
+  /**
+   * Maximum number of retries to perform before giving up.
+   */
+  public maxRetries: number = 4;
+
   /**
    * Client used for this call.
    */

src/cluster/errors.ts

@@ -10,6 +10,16 @@ export const isMovedError = (error: unknown): boolean => {
   return false;
 };
 
+export const isAskError = (error: unknown): boolean => {
+  if (error instanceof Error) {
+    const msg = error.message;
+    return msg.charCodeAt(0) === 65 && // A
+      msg.charCodeAt(1) === 83 && // S
+      msg.charCodeAt(2) === 75; // K
+  }
+  return false;
+};
+
 const movedErrorRegex = /^MOVED [0-9]+ ([^:]*):([0-9]+)\s*$/;
 export const parseMovedError = (message: string): [endpoint: string, port: number] => {
   const match = movedErrorRegex.exec(message);