[FIX] fixed an issue with ordered consumer where resetting the consumer didn't send the UNSUB, creating a situation where if there was no disconnect from the client, two subscriptions would be active on the server.

Author: aricart

jetstream/jsclient.ts

@@ -795,6 +795,8 @@ export class JetStreamSubscriptionImpl extends TypedSubscription<JsMsg>
     this.js._request(subj, req, { retries: -1 })
       .then((v) => {
         const ci = v as ConsumerInfo;
+        const jinfo = this.sub.info as JetStreamSubscriptionInfo;
+        jinfo.last = ci;
         this.info!.config = ci.config;
         this.info!.name = ci.name;
       })

nats-base-client/protocol.ts

@@ -995,6 +995,7 @@ export class ProtocolHandler implements Dispatcher<ParserEvent> {
     if (!s || this.isClosed()) {
       return;
     }
+    this.unsub(s);
     s.subject = subject;
     this.subscriptions.resub(s);
     // we don't auto-unsub here because we don't

tests/helpers/launcher.ts

@@ -72,6 +72,45 @@ export interface JSZ {
   };
 }
 
+export interface SubDetails {
+  subject: string;
+  sid: string;
+  msgs: number;
+  cid: number;
+}
+
+export interface Conn {
+  cid: number;
+  kind: string;
+  type: string;
+  ip: string;
+  port: number;
+  start: string;
+  "last_activity": string;
+  "rtt": string;
+  uptime: string;
+  idle: string;
+  "pending_bytes": number;
+  "in_msgs": number;
+  "out_msgs": number;
+  subscriptions: number;
+  name: string;
+  lang: string;
+  version: string;
+  subscriptions_list?: string[];
+  subscriptions_list_detail?: SubDetails[];
+}
+
+export interface ConnZ {
+  "server_id": string;
+  now: string;
+  "num_connections": number;
+  "total": number;
+  "offset": number;
+  "limit": number;
+  "connections": Conn[];
+}
+
 function parseHostport(
   s?: string,
 ): { hostname: string; port: number } | undefined {
@@ -316,6 +355,21 @@ export class NatsServer implements PortInfo {
     return await resp.json();
   }
 
+  async connz(cid?: number, subs: boolean | "detail" = true): Promise<ConnZ> {
+    if (!this.monitoring) {
+      return Promise.reject(new Error("server is not monitoring"));
+    }
+    const args = [];
+    args.push(`subs=${subs}`);
+    if (cid) {
+      args.push(`cid=${cid}`);
+    }
+
+    const qs = args.length ? args.join("&") : "";
+    const resp = await fetch(`http://127.0.0.1:${this.monitoring}/connz?${qs}`);
+    return await resp.json();
+  }
+
   async dataDir(): Promise<string | null> {
     const jsz = await this.jsz();
     return jsz.config.store_dir;

tests/resub_test.ts

@@ -15,8 +15,13 @@
 
 import { cleanup, setup } from "./helpers/mod.ts";
 import { NatsConnectionImpl } from "../nats-base-client/nats.ts";
-import { assertEquals } from "https://deno.land/std@0.221.0/assert/mod.ts";
-import { createInbox, Msg } from "../nats-base-client/core.ts";
+import {
+  assertEquals,
+  assertExists,
+  fail,
+} from "https://deno.land/std@0.221.0/assert/mod.ts";
+import { createInbox, Msg, NatsConnection } from "../nats-base-client/core.ts";
+import { NatsServer } from "./helpers/launcher.ts";
 
 Deno.test("resub - iter", async () => {
   const { ns, nc } = await setup();
@@ -75,3 +80,69 @@ Deno.test("resub - callback", async () => {
   assertEquals(buf[1].subject, subjb);
   await cleanup(ns, nc);
 });
+
+async function assertEqualSubs(
+  ns: NatsServer,
+  nc: NatsConnection,
+): Promise<void> {
+  const nci = nc as NatsConnectionImpl;
+  const cid = nc.info?.client_id || -1;
+  if (cid === -1) {
+    fail("client_id not found");
+  }
+
+  const connz = await ns.connz(cid, "detail");
+
+  const conn = connz.connections.find((c) => {
+    return c.cid === cid;
+  });
+  assertExists(conn);
+  assertExists(conn.subscriptions_list_detail);
+
+  const subs = nci.protocol.subscriptions.all();
+  subs.forEach((sub) => {
+    const ssub = conn.subscriptions_list_detail?.find((d) => {
+      return d.sid === `${sub.sid}`;
+    });
+    assertExists(ssub);
+    assertEquals(ssub.subject, sub.subject);
+  });
+}
+
+Deno.test("resub - removes server interest", async () => {
+  const { ns, nc } = await setup();
+
+  nc.subscribe("a", {
+    callback() {
+      // nothing
+    },
+  });
+
+  const nci = nc as NatsConnectionImpl;
+  let sub = nci.protocol.subscriptions.all().find((s) => {
+    return s.subject === "a";
+  });
+  assertExists(sub);
+
+  // assert the server sees the same subscriptions
+  await assertEqualSubs(ns, nc);
+
+  // change it
+  nci._resub(sub, "b");
+
+  // make sure we don't find a
+  sub = nci.protocol.subscriptions.all().find((s) => {
+    return s.subject === "a";
+  });
+  assertEquals(sub, undefined);
+
+  // make sure we find b
+  sub = nci.protocol.subscriptions.all().find((s) => {
+    return s.subject === "b";
+  });
+  assertExists(sub);
+
+  // assert server thinks the same thing
+  await assertEqualSubs(ns, nc);
+  await cleanup(ns, nc);
+});