core(responsiveness): use raw trace event

lighthouse-core/audits/metrics/experimental-interaction-to-next-paint.js

@@ -63,19 +63,21 @@ class ExperimentalInteractionToNextPaint extends Audit {
 
     const trace = artifacts.traces[Audit.DEFAULT_PASS];
     const metricData = {trace, settings};
-    const metricResult = await ComputedResponsivenes.request(metricData, context);
+    const responsivenessEvent = await ComputedResponsivenes.request(metricData, context);
 
     // TODO: include the no-interaction state in the report instead of using n/a.
-    if (metricResult === null) {
+    if (responsivenessEvent === null) {
       return {score: null, notApplicable: true};
     }
 
+    const timing = responsivenessEvent.args.data.maxDuration;
+
     return {
       score: Audit.computeLogNormalScore({p10: context.options.p10, median: context.options.median},
-        metricResult.timing),
-      numericValue: metricResult.timing,
+        timing),
+      numericValue: timing,
       numericUnit: 'millisecond',
-      displayValue: str_(i18n.UIStrings.ms, {timeInMs: metricResult.timing}),
+      displayValue: str_(i18n.UIStrings.ms, {timeInMs: timing}),
     };
   }
 }

lighthouse-core/computed/metrics/responsiveness.js

@@ -11,50 +11,51 @@
  * user input in the provided trace).
  */
 
+/** @typedef {LH.Trace.CompleteEvent & {name: 'Responsiveness.Renderer.UserInteraction', args: {frame: string, data: {interactionType: 'drag'|'keyboard'|'tapOrClick', maxDuration: number}}}} ResponsivenessEvent */
+
 const makeComputedArtifact = require('../computed-artifact.js');
 const ProcessedTrace = require('../processed-trace.js');
 
 class Responsiveness {
   /**
    * @param {LH.Artifacts.ProcessedTrace} processedTrace
-   * @return {{timing: number}|null}
+   * @return {ResponsivenessEvent|null}
    */
   static getHighPercentileResponsiveness(processedTrace) {
-    const durations = processedTrace.frameTreeEvents
+    const responsivenessEvents = processedTrace.frameTreeEvents
       // https://source.chromium.org/chromium/chromium/src/+/main:third_party/blink/renderer/core/timing/responsiveness_metrics.cc;l=146-150;drc=a1a2302f30b0a58f7669a41c80acdf1fa11958dd
-      .filter(e => e.name === 'Responsiveness.Renderer.UserInteraction')
-      .map(evt => evt.args.data?.maxDuration)
-      .filter(/** @return {duration is number} */duration => duration !== undefined)
-      .sort((a, b) => b - a);
+      .filter(/** @return {e is ResponsivenessEvent} */ e => {
+        return e.name === 'Responsiveness.Renderer.UserInteraction';
+      }).sort((a, b) => b.args.data.maxDuration - a.args.data.maxDuration);
 
     // If there were no interactions with the page, the metric is N/A.
-    if (durations.length === 0) {
+    if (responsivenessEvents.length === 0) {
       return null;
     }
 
     // INP is the "nearest-rank"/inverted_cdf 98th percentile, except Chrome only
     // keeps the 10 worst events around, so it can never be more than the 10th from
     // last array element. To keep things simpler, sort desc and pick from front.
     // See https://source.chromium.org/chromium/chromium/src/+/main:components/page_load_metrics/browser/responsiveness_metrics_normalization.cc;l=45-59;drc=cb0f9c8b559d9c7c3cb4ca94fc1118cc015d38ad
-    const index = Math.min(9, Math.floor(durations.length / 50));
+    const index = Math.min(9, Math.floor(responsivenessEvents.length / 50));
 
-    return {
-      timing: durations[index],
-    };
+    return responsivenessEvents[index];
   }
 
   /**
    * @param {{trace: LH.Trace, settings: Immutable<LH.Config.Settings>}} data
    * @param {LH.Artifacts.ComputedContext} context
-   * @return {Promise<LH.Artifacts.Metric|null>}
+   * @return {Promise<ResponsivenessEvent|null>}
    */
   static async compute_(data, context) {
     if (data.settings.throttlingMethod === 'simulate') {
       throw new Error('Responsiveness currently unsupported by simulated throttling');
     }
 
     const processedTrace = await ProcessedTrace.request(data.trace, context);
-    return Responsiveness.getHighPercentileResponsiveness(processedTrace);
+    const event = Responsiveness.getHighPercentileResponsiveness(processedTrace);
+
+    return JSON.parse(JSON.stringify(event));
   }
 }
 

lighthouse-core/test/computed/metrics/responsiveness-test.js

@@ -74,8 +74,8 @@ describe('Metric: Responsiveness', () => {
       settings: {throttlingMethod: 'provided'},
     };
     const context = {computedCache: new Map()};
-    const result = await Responsiveness.request(metricInputData, context);
-    expect(result).toEqual(null);
+    const event = await Responsiveness.request(metricInputData, context);
+    expect(event).toEqual(null);
   });
 
   it('should select the 98th percentile interaction', async () => {
@@ -100,8 +100,8 @@ describe('Metric: Responsiveness', () => {
       }
 
       const context = {computedCache: new Map()};
-      const result = await Responsiveness.request(metricInputData, context);
-      assert.equal(result.timing, expectedTiming, `error at ${eventCount} events`);
+      const event = await Responsiveness.request(metricInputData, context);
+      assert.equal(event.args.data.maxDuration, expectedTiming, `error at ${eventCount} events`);
     }
   });
 
@@ -129,8 +129,8 @@ describe('Metric: Responsiveness', () => {
       settings: {throttlingMethod: 'provided'},
     };
     const context = {computedCache: new Map()};
-    const result = await Responsiveness.request(metricInputData, context);
-    expect(result).toEqual({timing: 49});
+    const event = await Responsiveness.request(metricInputData, context);
+    expect(event.args.data).toMatchObject({maxDuration: 49});
   });
 
   it('should throw on attempting with a simulated timespan', async () => {
@@ -148,8 +148,8 @@ describe('Metric: Responsiveness', () => {
       settings: {throttlingMethod: 'provided'},
     };
     const context = {computedCache: new Map()};
-    const result = await Responsiveness.request(metricInputData, context);
-    expect(result).toEqual({timing: 392});
+    const event = await Responsiveness.request(metricInputData, context);
+    expect(event.args.data).toMatchObject({maxDuration: 392});
   });
 
   it('evaluates from a real trace with no interaction events', async () => {
@@ -158,7 +158,7 @@ describe('Metric: Responsiveness', () => {
       settings: {throttlingMethod: 'provided'},
     };
     const context = {computedCache: new Map()};
-    const result = await Responsiveness.request(metricInputData, context);
-    expect(result).toEqual(null);
+    const event = await Responsiveness.request(metricInputData, context);
+    expect(event).toEqual(null);
   });
 });

types/artifacts.d.ts

@@ -1020,6 +1020,23 @@ export interface TraceEvent {
   };
 }
 
+declare module Trace {
+  /**
+   * Base event of a `ph: 'X'` 'complete' event. Extend with `name` and `args` as
+   * needed.
+   */
+  interface CompleteEvent {
+    ph: 'X';
+    cat: string;
+    pid: number;
+    tid: number;
+    dur: number;
+    ts: number;
+    tdur: number;
+    tts: number;
+  }
+}
+
 /**
  * A record of DevTools Debugging Protocol events.
  */