fix: disambiguate repeated-target event timing

src/testing/performance-instrumentation.ts

@@ -30,6 +30,7 @@ export interface ScriptedActionSample {
   id: string;
   target: string;
   dispatchTime: number;
+  captureEndTime: number | null;
   acknowledgementCount: number;
   mutationTime: number | null;
   doubleRafTime: number | null;
@@ -111,6 +112,7 @@ export const evaluateEventToNextPaint = (
       entry.target === action.target
       && entry.startTime >= action.dispatchTime
       && entry.startTime <= action.dispatchTime + 500
+      && (action.captureEndTime === null || entry.startTime < action.captureEndTime)
     ));
     if (matching.length === 0) return 16;
     const groups = new Map<number, number>();
@@ -270,7 +272,9 @@ export const installAuthorizedPerformanceInstrumentation = async (): Promise<voi
         for (const entry of list.getEntries()) {
           const timed = entry as PerformanceEntry & { interactionId?: number; target?: Node | null };
           for (const record of actionRecords.values()) {
-            if (timed.target === record.element) {
+            if (timed.target === record.element
+              && timed.startTime >= record.dispatchTime
+              && (record.captureEndTime === null || timed.startTime < record.captureEndTime)) {
               (record.eventEntries as EventTimingSample[]).push({
                 target: record.id,
                 startTime: timed.startTime,
@@ -360,10 +364,15 @@ export const installAuthorizedPerformanceInstrumentation = async (): Promise<voi
       if (!exactActionIds.has(id) || actionRecords.has(id)) throw new Error('The performance action is invalid or duplicated.');
       const element = document.querySelector(selector);
       if (!(element instanceof Element)) throw new Error('The performance action target is unavailable.');
+      const dispatchTime = performance.now();
+      for (const record of actionRecords.values()) {
+        if (record.element === element && record.captureEndTime === null) record.captureEndTime = dispatchTime;
+      }
       actionRecords.set(id, {
         id,
         target: id,
-        dispatchTime: performance.now(),
+        dispatchTime,
+        captureEndTime: null,
         acknowledgementCount: 0,
         mutationTime: null,
         doubleRafTime: null,

tests/performance/metrics.test.ts

@@ -63,6 +63,7 @@ describe('performance metric math', () => {
       id,
       target: `target-${id}`,
       dispatchTime: index * 1_000,
+      captureEndTime: null,
       acknowledgementCount: 1,
       mutationTime: index * 1_000 + 20,
       doubleRafTime: index * 1_000 + 40,
@@ -74,6 +75,52 @@ describe('performance metric math', () => {
     expect(() => evaluateEventToNextPaint([{ ...actions[0]!, acknowledgementCount: 2 }, ...actions.slice(1)])).toThrow(/acknowledgement/u);
   });
 
+  it('excludes a later compressed interaction when sequential actions share one DOM target', () => {
+    const ids = ['start', 'volume', 'mute', 'unmute', 'pause', 'resume', 'toolkit', 'contact'] as const;
+    const actions = ids.map((id, index): ScriptedActionSample => ({
+      id,
+      target: id,
+      dispatchTime: index === 4 ? 400 : index === 5 ? 450 : index * 1_000,
+      captureEndTime: index === 4 ? 450 : null,
+      acknowledgementCount: 1,
+      mutationTime: (index === 4 ? 400 : index === 5 ? 450 : index * 1_000) + 5,
+      doubleRafTime: (index === 4 ? 400 : index === 5 ? 450 : index * 1_000) + 10,
+      eventTimingSupported: true,
+      eventEntries: id === 'pause'
+        ? [
+            { target: 'pause', startTime: 410, duration: 30, interactionId: 41 },
+            { target: 'pause', startTime: 460, duration: 40, interactionId: 42 },
+          ]
+        : id === 'resume'
+          ? [{ target: 'resume', startTime: 460, duration: 40, interactionId: 42 }]
+          : [],
+    }));
+
+    expect(evaluateEventToNextPaint(actions).values.slice(4, 6)).toEqual([30, 40]);
+  });
+
+  it('still rejects genuinely ambiguous interaction groups within one capture window', () => {
+    const ids = ['start', 'volume', 'mute', 'unmute', 'pause', 'resume', 'toolkit', 'contact'] as const;
+    const actions = ids.map((id, index): ScriptedActionSample => ({
+      id,
+      target: id,
+      dispatchTime: index * 1_000,
+      captureEndTime: null,
+      acknowledgementCount: 1,
+      mutationTime: index * 1_000 + 5,
+      doubleRafTime: index * 1_000 + 10,
+      eventTimingSupported: true,
+      eventEntries: id === 'pause'
+        ? [
+            { target: 'pause', startTime: 4_010, duration: 30, interactionId: 41 },
+            { target: 'pause', startTime: 4_020, duration: 40, interactionId: 42 },
+          ]
+        : [],
+    }));
+
+    expect(() => evaluateEventToNextPaint(actions)).toThrow(/ambiguous/u);
+  });
+
   it('evaluates scene continuity at interval boundaries and callback coverage', () => {
     const result = evaluateSceneContinuity(
       [{ start: 0, end: 100 }],