fix: 按 K-00 约定修复 JS SDK 断线重交与退避

sdk/js/src/fake.ts

@@ -11,9 +11,11 @@ export interface FakeConnect {
   cleanStart: boolean;
   sessionExpiry: number;
   password: string;
+  receiveMaximumSet: boolean;
+  keepalive: number;
 }
 
-/** 单测用假 MQTT。 */
+/** 单测用假 MQTT，不从包入口导出。 */
 export class FakeTransport implements Transport {
   private cfg?: TransportConfig;
   private cred = "";
@@ -25,6 +27,7 @@ export class FakeTransport implements Transport {
   maxBodyBytes = 262144;
   maxMetaBytes = 4096;
   maxFrameBytes = 786432;
+  publishUpImpl?: (payload: string) => Promise<void>;
 
   setCredential(passwordOrToken: string): void {
     this.cred = passwordOrToken;
@@ -32,11 +35,16 @@ export class FakeTransport implements Transport {
 
   async start(cfg: TransportConfig): Promise<void> {
     this.cfg = cfg;
-    await this.simulateConnectOK();
+    queueMicrotask(() => {
+      void this.simulateConnectOK().catch(() => {});
+    });
   }
 
   async publishUp(payload: Uint8Array | string): Promise<void> {
     const s = typeof payload === "string" ? payload : new TextDecoder().decode(payload);
+    if (this.publishUpImpl) {
+      await this.publishUpImpl(s);
+    }
     this.up.push(s);
     if (this.autoHello) {
       try {
@@ -49,7 +57,7 @@ export class FakeTransport implements Transport {
   }
 
   async stop(): Promise<void> {
-    this.cfg?.onOffline();
+    /* 不触发 onOffline，避免 close 后误重连 */
   }
 
   private replyHello(rid: string): void {
@@ -75,7 +83,13 @@ export class FakeTransport implements Transport {
 
   async simulateConnectOK(): Promise<void> {
     const { cleanStart, sessionExpiry } = buildCleanConnectFlags();
-    this.connects.push({ cleanStart, sessionExpiry, password: this.cred });
+    this.connects.push({
+      cleanStart,
+      sessionExpiry,
+      password: this.cred,
+      receiveMaximumSet: false,
+      keepalive: 30,
+    });
     this.cfg?.onConnectPacket?.(cleanStart, sessionExpiry);
     this.cfg?.backoff.markOnline();
     await this.cfg?.mqttReady();
@@ -95,6 +109,15 @@ export class FakeTransport implements Transport {
     this.cfg?.onKicked();
   }
 
+  simulateServerDisconnect(code: number): void {
+    if (code === 0x8e) {
+      this.cfg?.onKicked();
+      return;
+    }
+    this.cfg?.backoff.markOffline();
+    this.cfg?.onOffline();
+  }
+
   injectDown(payload: string | Uint8Array): void {
     const bytes = typeof payload === "string" ? new TextEncoder().encode(payload) : payload;
     this.cfg?.onDown(bytes);