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GoogleChrome · May 30, 2017 · 184537b · 184537b
1 parent ef2eccd
commit 184537b
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Showing 3 changed files with 13 additions and 8 deletions.
diff --git a/lighthouse-core/gather/computed/trace-of-tab.js b/lighthouse-core/gather/computed/trace-of-tab.js
@@ -98,7 +98,11 @@ class TraceOfTab extends ComputedArtifact {
       .filter(e => e.pid === startedInPageEvt.pid)
       .sort((event0, event1) => event0.ts - event1.ts);
 
-    const traceEnd = trace.traceEvents.reduce((max, evt) => {
+    const earliestTraceEvt = trace.traceEvents.reduce((min, evt) => {
+      return evt.ts === 0 || min.ts <= evt.ts ? min : evt;
+    }, {ts: Infinity});
+
+    const latestTraceEvt = trace.traceEvents.reduce((max, evt) => {
       return max.ts > evt.ts ? max : evt;
     });
 
@@ -107,7 +111,7 @@ class TraceOfTab extends ComputedArtifact {
       firstPaint,
       firstContentfulPaint,
       firstMeaningfulPaint,
-      traceEnd,
+      traceEnd: latestTraceEvt,
       onLoad,
       domContentLoaded,
     };
@@ -124,7 +128,9 @@ class TraceOfTab extends ComputedArtifact {
       timings,
       timestamps,
       processEvents,
-      startedInPageEvt: startedInPageEvt,
+      earliestTraceEvt,
+      latestTraceEvt,
+      startedInPageEvt,
       navigationStartEvt: navigationStart,
       firstPaintEvt: firstPaint,
       firstContentfulPaintEvt: firstContentfulPaint,

diff --git a/lighthouse-core/lib/traces/tracing-processor.js b/lighthouse-core/lib/traces/tracing-processor.js
@@ -130,10 +130,8 @@ class TraceProcessor {
    */
   static getRiskToResponsiveness(tabTrace, startTime, endTime, percentiles) {
     const navStart = tabTrace.navigationStartEvt.ts;
-    const traceStart = tabTrace.processEvents
-        .filter(evt => evt.ts !== 0)
-        .reduce((min, evt) => Math.min(evt.ts, min), Infinity);
-    const traceEnd = tabTrace.processEvents.reduce((max, evt) => Math.max(evt.ts, max), -Infinity);
+    const traceStart = tabTrace.earliestTraceEvt.ts;
+    const traceEnd = tabTrace.latestTraceEvt.ts;
 
     // Range of responsiveness we care about. Default to bounds of model.
     startTime = startTime === undefined ? (traceStart - navStart) / 1000 : startTime;
@@ -200,6 +198,7 @@ class TraceProcessor {
   static getMainThreadTopLevelEvents(tabTrace, startTime = -Infinity, endTime = Infinity) {
     let lastEvt = {start: -Infinity, end: -Infinity};
     const topLevelEvents = [];
+    // note: processEvents is already sorted by event start
     for (const event of tabTrace.processEvents) {
       if (event.name !== SCHEDULABLE_TASK_TITLE || !event.dur) continue;
 

diff --git a/lighthouse-core/test/lib/traces/tracing-processor-test.js b/lighthouse-core/test/lib/traces/tracing-processor-test.js
@@ -241,7 +241,7 @@ describe('TracingProcessor lib', () => {
       const tabTrace = new TraceOfTab().compute_(trace);
       const ret = TracingProcessor.getRiskToResponsiveness(tabTrace);
       assert.equal(ret.durations.length, 637);
-      assert.equal(Math.round(ret.totalTime), 2157);
+      assert.equal(Math.round(ret.totalTime), 2159);
       assert.equal(ret.clippedLength, 0);
       assert.deepEqual(ret.percentiles, [0.5, 0.75, 0.9, 0.99, 1]);
     });