feat(lifecycle): enhance CDP disconnect handling during change checks and extension reloads

Author: AndyLiner13

src/host-pipe.ts

@@ -256,6 +256,8 @@ export interface CheckForChangesResult {
   extRebuilt: boolean;
   extBuildError: string | null;
   extClientReloaded: boolean;
+  newCdpPort?: number;
+  newClientStartedAt?: number;
 }
 
 /**

src/main.ts

@@ -271,6 +271,18 @@ const pipeline = new RequestPipeline({
   mcpServerRoot: mcpServerDir,
   extensionPath: config.extensionBridgePath,
   hotReloadEnabled: config.hotReload.enabled && config.explicitExtensionDevelopmentPath,
+  onBeforeChangeCheck: () => {
+    lifecycleService.suppressCdpDisconnectDuringChangeCheck();
+  },
+  onAfterChangeCheck: async (result) => {
+    lifecycleService.resumeCdpDisconnectHandling();
+    if (result.extClientReloaded && result.newCdpPort) {
+      await lifecycleService.reconnectAfterExtensionReload(
+        result.newCdpPort,
+        result.newClientStartedAt,
+      );
+    }
+  },
 });
 
 function registerTool(targetServer: McpServer, tool: ToolDefinition): void {

src/services/LifecycleService.ts

@@ -36,6 +36,12 @@ class LifecycleService {
   private exitCleanupDone = false;
   private shutdownHandlersRegistered = false;
 
+  /**
+   * When true, CDP disconnect events are suppressed (not treated as crashes).
+   * Set during checkForChanges RPC which may kill the Client window.
+   */
+  private _changeCheckInProgress = false;
+
   /** Client workspace folder the MCP server controls */
   private _clientWorkspace: string | undefined;
   /** Extension development path for the Client */
@@ -254,7 +260,8 @@ class LifecycleService {
 
     // Unexpected CDP close → user closed the debug window → exit
     cdpService.setDisconnectHandler((intentional, lastPort) => {
-      if (intentional) {
+      if (intentional || this._changeCheckInProgress) {
+        logger(`[Lifecycle] CDP closed (suppressed — intentional=${intentional}, changeCheck=${this._changeCheckInProgress})`);
         return;
       }
 
@@ -285,6 +292,45 @@ class LifecycleService {
 
   // ── State Getters ──────────────────────────────────────
 
+  // ── Change Check CDP Suppression ────────────────────────
+
+  /**
+   * Suppress CDP disconnect handling during checkForChanges RPC.
+   * The extension may kill the Client window during this RPC,
+   * which would otherwise be treated as "user closed debug window".
+   */
+  suppressCdpDisconnectDuringChangeCheck(): void {
+    this._changeCheckInProgress = true;
+    logger('[Lifecycle] CDP disconnect suppressed for change check');
+  }
+
+  /**
+   * Resume normal CDP disconnect handling after checkForChanges.
+   */
+  resumeCdpDisconnectHandling(): void {
+    this._changeCheckInProgress = false;
+    logger('[Lifecycle] CDP disconnect handling resumed');
+  }
+
+  /**
+   * Update internal state after the extension reloaded the Client.
+   * Reconnects CDP to the new port and re-inits event subscriptions.
+   */
+  async reconnectAfterExtensionReload(newCdpPort: number, clientStartedAt?: number): Promise<void> {
+    logger(`[Lifecycle] Reconnecting CDP after extension reload — new port: ${newCdpPort}`);
+
+    // Disconnect old CDP (if still lingering) — intentional
+    cdpService.disconnect();
+    clearCdpEventData();
+
+    this._cdpPort = newCdpPort;
+    await cdpService.connect(newCdpPort);
+    await initCdpEventSubscriptions();
+
+    this._debugWindowStartedAt = clientStartedAt ?? Date.now();
+    logger(`[Lifecycle] Extension reload reconnect complete — sessionTs=${new Date(this._debugWindowStartedAt).toISOString()}`);
+  }
+
   get isConnected(): boolean {
     return cdpService.isConnected;
   }

src/services/requestPipeline.ts

@@ -71,6 +71,8 @@ export interface ChangeCheckResult {
   extRebuilt: boolean;
   extBuildError: string | null;
   extClientReloaded: boolean;
+  newCdpPort?: number;
+  newClientStartedAt?: number;
 }
 
 interface PipelineEntry {
@@ -100,6 +102,10 @@ export interface PipelineDeps {
   extensionPath: string;
   /** Master switch — when false, all hot-reload checks are skipped. */
   hotReloadEnabled: boolean;
+  /** Suppress CDP disconnect handling before checkForChanges (extension may kill Client). */
+  onBeforeChangeCheck?: () => void;
+  /** Restore CDP disconnect handling + reconnect CDP if extension reloaded Client. */
+  onAfterChangeCheck?: (result: ChangeCheckResult) => Promise<void>;
 }
 
 // ── RequestPipeline ──────────────────────────────────────
@@ -206,6 +212,9 @@ export class RequestPipeline {
   ): Promise<ChangeCheckResult | null> {
     let check: ChangeCheckResult;
 
+    // Suppress CDP disconnect handling — extension may kill Client during rebuild
+    this.deps.onBeforeChangeCheck?.();
+
     try {
       check = await this.deps.checkForChanges(
         this.deps.mcpServerRoot,
@@ -215,7 +224,7 @@ export class RequestPipeline {
       // checkForChanges RPC failed — proceed in degraded mode
       const message = err instanceof Error ? err.message : String(err);
       logger(`[pipeline] checkForChanges RPC failed: ${message} — proceeding without hot-reload check`);
-      return {
+      check = {
         mcpChanged: false,
         mcpRebuilt: false,
         mcpBuildError: null,
@@ -226,6 +235,14 @@ export class RequestPipeline {
       };
     }
 
+    // Restore CDP disconnect handling + reconnect if extension reloaded Client
+    try {
+      await this.deps.onAfterChangeCheck?.(check);
+    } catch (afterErr) {
+      const msg = afterErr instanceof Error ? afterErr.message : String(afterErr);
+      logger(`[pipeline] onAfterChangeCheck failed: ${msg}`);
+    }
+
     // Extension build failure → return error, skip tool execution
     if (check.extBuildError) {
       entry.resolve({