fix(simulator): improve PTY stabilization and stall recovery

packages/cli/src/services/UserSimulator.test.ts

@@ -190,42 +190,42 @@ describe('UserSimulator', () => {
     vi.useRealTimers();
   });
 
-  it('should re-evaluate if internal tool state changes even if screen content is static', async () => {
+  it('should terminate if terminal state does not change after 3 consecutive inputs', async () => {
+    const exitSpy = vi.spyOn(process, 'exit').mockImplementation(() => {
+      return undefined as never;
+    });
     const simulator = new UserSimulator(
       mockConfig,
       mockGetScreen,
       mockStdinBuffer,
     );
-    mockGetScreen.mockReturnValue('Responding...');
+    mockGetScreen.mockReturnValue('Static Screen');
+    mockContentGenerator.generateContent.mockResolvedValue({
+      text: JSON.stringify({ action: 'y\r' }),
+    });
 
     vi.useFakeTimers();
     simulator.start();
 
-    // Trigger first tick
+    // Tick 1: Action sent, state recorded
     await vi.advanceTimersByTimeAsync(2000);
     expect(mockContentGenerator.generateContent).toHaveBeenCalledTimes(1);
 
-    // Trigger second tick with same screen - should skip
+    // Tick 2: Same screen, action sent, stall count = 1
-    await vi.advanceTimersByTimeAsync(2000);
-    expect(mockContentGenerator.generateContent).toHaveBeenCalledTimes(1);
-
-    // Simulate tool call update
-    const handler = mockMessageBus.subscribe.mock.calls[0][1];
-    handler({
-      type: MessageBusType.TOOL_CALLS_UPDATE,
-      toolCalls: [
-        {
-          status: CoreToolCallStatus.AwaitingApproval,
-          request: { callId: '123', name: 'test_tool' },
-        },
-      ],
-    });
-
-    // Trigger third tick with same screen but new tool state - should NOT skip
     await vi.advanceTimersByTimeAsync(2000);
     expect(mockContentGenerator.generateContent).toHaveBeenCalledTimes(2);
 
+    // Tick 3: Same screen, action sent, stall count = 2
+    await vi.advanceTimersByTimeAsync(2000);
+    expect(mockContentGenerator.generateContent).toHaveBeenCalledTimes(3);
+
+    // Tick 4: Same screen, should trigger termination
+    await vi.advanceTimersByTimeAsync(2000);
+
+    expect(exitSpy).toHaveBeenCalledWith(1);
+
     simulator.stop();
+    exitSpy.mockRestore();
     vi.useRealTimers();
   });
 
@@ -304,9 +304,11 @@ describe('UserSimulator', () => {
         (call) => call[1] === 'simulator-compression',
       );
     expect(compressionCall).toBeDefined();
-    expect(compressionCall[0].contents[0].parts[0].text).toContain(
+    if (compressionCall) {
-      'Summarize the following chronological session notes',
+      expect(compressionCall[0].contents[0].parts[0].text).toContain(
-    );
+        'Summarize the following chronological session notes',
+      );
+    }
 
     // Wait for the compression to finish and merge.
     // We need to resolve the promise for the compression call.
@@ -332,10 +334,11 @@ describe('UserSimulator', () => {
         call[1] === 'simulator-prompt',
     );
 
-    const finalPrompt = finalCall[0].contents[0].parts[0].text;
+    expect(finalCall).toBeDefined();
-    expect(finalPrompt).toContain('1. Compressed Summary');
+    if (finalCall) {
-    // Note 5 (the one added during or after compression trigger) might be there too
+      const finalPrompt = finalCall[0].contents[0].parts[0].text;
-    // depending on timing, but 'Compressed Summary' must be there.
+      expect(finalPrompt).toContain('1. Compressed Summary');
+    }
 
     simulator.stop();
     vi.useRealTimers();

packages/cli/src/services/UserSimulator.ts

@@ -32,6 +32,7 @@ export class UserSimulator {
   private lastStateKey = '';
   private isProcessing = false;
   private isCompressingMemory = false;
+  private consecutiveStallCount = 0;
   private staleCycleCount = 0;
   private interactionsFile: string | null = null;
 
@@ -116,6 +117,12 @@ export class UserSimulator {
 
     try {
       this.isProcessing = true;
+
+      // Stabilization delay: Wait for the terminal UI to finish rendering
+      // (e.g. ANSI clear/repaint sequences) before looking at the screen.
+      // Increased to 1s to handle high-latency PTYs in Docker.
+      await new Promise((resolve) => setTimeout(resolve, 1000));
+
       const screen = this.getScreen();
       if (!screen) return;
 
@@ -128,10 +135,12 @@ export class UserSimulator {
         .replace(/\n([ \t]*\n)+/g, '\n\n');
 
       const normalizedScreen = strippedScreen
-        .replace(/[\u2800-\u28FF]/g, '')
+        .replace(/[\u2800-\u28FF]/g, '') // Braille patterns
-        .replace(/[|/-\\]/g, '')
+        .replace(/[|/-\\]/g, '') // Spinners
-        .replace(/\b\d+(\.\d+)?s\b/g, '')
+        .replace(/\b\d+(\.\d+)?s\b/g, '') // Timers (seconds)
-        .replace(/\b\d+m(\s+\d+s)?\b/g, '')
+        .replace(/\b\d+m(\s+\d+s)?\b/g, '') // Timers (minutes)
+        .replace(/\b\d+%\b/g, '') // Percentages
+        .replace(/\b\d+\/\d+\b/g, '') // Progress ratios (e.g. 1/10)
         .replace(/\(\s*\)/g, '')
         .trim();
 
@@ -142,16 +151,46 @@ export class UserSimulator {
       const currentStateKey = `${normalizedScreen}::${pendingIds}`;
 
       if (currentStateKey === this.lastStateKey) {
-        if (this.pendingToolCalls.length > 0) {
+        const lastAction = this.actionHistory[this.actionHistory.length - 1];
-          this.staleCycleCount++;
+        if (lastAction && lastAction !== '<WAIT>') {
-          // Every 10 ticks (10s) on a static screen while blocked, we try a prompt
+          this.consecutiveStallCount++;
-          if (this.staleCycleCount % 10 !== 0) {
+          
-            return;
+          // Increased limit to 10 for high-load environments.
+          if (this.consecutiveStallCount >= 10) {
+            const errorMsg =
+              `[SIMULATOR] CRITICAL STALL DETECTED: Terminal state has not changed after ${this.consecutiveStallCount} consecutive inputs. Terminating to prevent loop.`;
+            debugLogger.error(errorMsg);
+            if (this.interactionsFile) {
+              fs.appendFileSync(
+                this.interactionsFile,
+                `[ERROR] ${errorMsg}\n\n`,
+              );
+            }
+            // eslint-disable-next-line no-console
+            console.error(`\n${errorMsg}`);
+            this.stop();
+            process.exit(1);
+          }
+          
+          // RECOVERY: If screen is blank and we are stalled, try a terminal refresh.
+          if (normalizedScreen.length === 0 && this.pendingToolCalls.length > 0) {
+             debugLogger.log('[SIMULATOR] Screen is blank but system is BLOCKED. Sending refresh carriage return.');
+             this.stdinBuffer.write('\r');
+             return;
           }
         } else {
-          return;
+          // If it was a <WAIT> action or no action yet, we still want the 10s fallback for internal state sync
+          if (this.pendingToolCalls.length > 0) {
+            this.staleCycleCount++;
+            if (this.staleCycleCount % 10 !== 0) {
+              return;
+            }
+          } else {
+            return;
+          }
         }
       } else {
+        this.consecutiveStallCount = 0;
         this.staleCycleCount = 0;
       }
       this.lastStateKey = currentStateKey;
@@ -277,7 +316,7 @@ ${strippedScreen}
         if (startIdx !== -1 && endIdx !== -1 && endIdx > startIdx) {
           cleanJson = cleanJson.substring(startIdx, endIdx + 1);
         } else {
-          cleanJson = cleanJson.replace(/^```json\s*|\s*```$/gm, '').trim();
+          cleanJson = cleanJson.replace(/^\`\`\`json\s*|\s*\`\`\`$/gm, '').trim();
         }
         // eslint-disable-next-line @typescript-eslint/no-unsafe-type-assertion
         parsedJson = JSON.parse(cleanJson) as SimulatorResponse;
@@ -301,7 +340,7 @@ ${strippedScreen}
           /^\d+\\r$/.test(text) ||
           text === '\\r'
         ) {
-          responseText = text.replace(/^[`"']+|[`"']+$/g, '');
+          responseText = text.replace(/^[\`\"']+|[\`\"']+$/g, '');
         } else {
           responseText = ''; // Prevent typing broken JSON string
         }