fix: resolve lifecycle memory leaks by cleaning up listeners and root closures (#25049)

packages/core/src/services/shellExecutionService.test.ts

@@ -208,6 +208,7 @@ describe('ShellExecutionService', () => {
   beforeEach(() => {
     vi.clearAllMocks();
     ExecutionLifecycleService.resetForTest();
+    ShellExecutionService.resetForTest();
     mockSerializeTerminalToObject.mockReturnValue([]);
     mockIsBinary.mockReturnValue(false);
     mockPlatform.mockReturnValue('linux');
@@ -1247,6 +1248,8 @@ describe('ShellExecutionService child_process fallback', () => {
 
   beforeEach(() => {
     vi.clearAllMocks();
+    ExecutionLifecycleService.resetForTest();
+    ShellExecutionService.resetForTest();
 
     mockIsBinary.mockReturnValue(false);
     mockPlatform.mockReturnValue('linux');
@@ -1662,6 +1665,8 @@ describe('ShellExecutionService execution method selection', () => {
 
   beforeEach(() => {
     vi.clearAllMocks();
+    ExecutionLifecycleService.resetForTest();
+    ShellExecutionService.resetForTest();
     onOutputEventMock = vi.fn();
 
     // Mock for pty
@@ -1786,6 +1791,8 @@ describe('ShellExecutionService environment variables', () => {
 
   beforeEach(() => {
     vi.clearAllMocks();
+    ExecutionLifecycleService.resetForTest();
+    ShellExecutionService.resetForTest();
     vi.resetModules(); // Reset modules to ensure process.env changes are fresh
 
     // Mock for pty

packages/core/src/services/shellExecutionService.ts

@@ -704,7 +704,10 @@ export class ShellExecutionService {
 
         const finalStrippedOutput = stripAnsi(combinedOutput).trim();
         const exitCode = code;
-        const exitSignal = signal ? os.constants.signals[signal] : null;
+        const exitSignal =
+          signal && os.constants.signals
+            ? (os.constants.signals[signal] ?? null)
+            : null;
 
         const resultPayload: ShellExecutionResult = {
           rawOutput: Buffer.from(''),
@@ -1503,4 +1506,16 @@ export class ShellExecutionService {
       signal: info.signal,
     }));
   }
+
+  /**
+   * Resets the internal state of the ShellExecutionService.
+   * This is intended for use in tests to ensure isolation.
+   */
+  static resetForTest(): void {
+    this.activePtys.clear();
+    this.activeChildProcesses.clear();
+    this.backgroundLogPids.clear();
+    this.backgroundLogStreams.clear();
+    this.backgroundProcessHistory.clear();
+  }
 }

packages/core/src/tools/mcp-client.ts

@@ -812,7 +812,7 @@ type StatusChangeListener = (
   serverName: string,
   status: MCPServerStatus,
 ) => void;
-const statusChangeListeners: StatusChangeListener[] = [];
+const statusChangeListeners: Set<StatusChangeListener> = new Set();
 
 /**
  * Add a listener for MCP server status changes
@@ -820,7 +820,7 @@ const statusChangeListeners: StatusChangeListener[] = [];
 export function addMCPStatusChangeListener(
   listener: StatusChangeListener,
 ): void {
-  statusChangeListeners.push(listener);
+  statusChangeListeners.add(listener);
 }
 
 /**
@@ -829,10 +829,7 @@ export function addMCPStatusChangeListener(
 export function removeMCPStatusChangeListener(
   listener: StatusChangeListener,
 ): void {
-  const index = statusChangeListeners.indexOf(listener);
-  if (index !== -1) {
-    statusChangeListeners.splice(index, 1);
-  }
+  statusChangeListeners.delete(listener);
 }
 
 /**