debugger: defer pause to avoid pause forever

lib/internal/debugger/inspect_probe.js

@@ -474,6 +474,8 @@ class ProbeInspectorSession {
     this.inFlight = null;
     // Most recently completed probe, used for `error.probe` when a non-evaluate CDP call rejects.
     this.lastProbeIndex = null;
+    this.deferredStartupPause = null;
+    this.handledPauseAfterStart = false;
     const { promise, resolve } = PromiseWithResolvers();
     this.completionPromise = promise;
     this.resolveCompletion = resolve;
@@ -624,10 +626,17 @@ class ProbeInspectorSession {
 
   async handlePaused(params) {
     if (this.finished) { return; }
-    // Ignore pauses that arrive before breakpoint setup is complete. Once
+    // Defer pauses that arrive before breakpoint setup is complete. Once
     // startup is marked complete, `Runtime.runIfWaitingForDebugger` may surface
-    // the initial --inspect-brk pause, which the normal resume path handles.
-    if (!this.started) { return; }
+    // the initial --inspect-brk pause, which the normal resume path handles. If
+    // it was already surfaced while binding breakpoints, replay it after startup
+    // so the target is not left paused forever.
+    if (!this.started) {
+      this.deferredStartupPause = params;
+      return;
+    }
+
+    this.handledPauseAfterStart = true;
 
     const hitBreakpoints = params.hitBreakpoints;
     if (hitBreakpoints === undefined || hitBreakpoints.length === 0) {
@@ -676,6 +685,16 @@ class ProbeInspectorSession {
     await this.resume();
   }
 
+  async handleDeferredStartupPause() {
+    if (this.deferredStartupPause === null || this.handledPauseAfterStart) {
+      return;
+    }
+
+    const params = this.deferredStartupPause;
+    this.deferredStartupPause = null;
+    await this.handlePaused(params);
+  }
+
   async evaluateProbe(callFrameId, probeIndex, location) {
     if (this.finished) { return; }
     const probe = this.probes[probeIndex];
@@ -998,6 +1017,7 @@ class ProbeInspectorSession {
         this.started = true;
         this.startTimeout();
         await this.callCdp('Runtime.runIfWaitingForDebugger');
+        await this.handleDeferredStartupPause();
       } catch (err) {
         if (err !== kInspectorFailedSentinel) { throw err; }
       }

test/parallel/test-debugger-probe-startup-pause.js

@@ -1,5 +1,5 @@
 // Flags: --expose-internals
-// This tests that probe mode ignores pauses until startup has finished binding
+// This tests that probe mode defers pauses until startup has finished binding
 // breakpoints.
 'use strict';
 
@@ -25,7 +25,7 @@ async function testStartupPauseHandling() {
   assert.deepStrictEqual(cdpCalls, []);
 
   session.started = true;
-  await session.handlePaused({});
+  await session.handleDeferredStartupPause();
   assert.deepStrictEqual(cdpCalls, ['Debugger.resume']);
 }