if we reduce significant digits with toFixed, always return to number.

GoogleChrome · Dec 14, 2016 · 562aee4 · 562aee4
1 parent 99b573f
commit 562aee4
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Showing 3 changed files with 13 additions and 12 deletions.
diff --git a/lighthouse-core/audits/first-meaningful-paint.js b/lighthouse-core/audits/first-meaningful-paint.js
@@ -87,8 +87,8 @@ class FirstMeaningfulPaint extends Audit {
       },
       timings: {
         navStart: 0,
-        fCP: firstContentfulPaint,
-        fMP: firstMeaningfulPaint
+        fCP: parseFloat(firstContentfulPaint.toFixed(3)),
+        fMP: parseFloat(firstMeaningfulPaint.toFixed(3))
       }
     };
 
@@ -107,7 +107,7 @@ class FirstMeaningfulPaint extends Audit {
     return {
       duration: `${firstMeaningfulPaint.toFixed(1)}`,
       score: Math.round(score),
-      rawValue: firstMeaningfulPaint.toFixed(1),
+      rawValue: parseFloat(firstMeaningfulPaint.toFixed(1)),
       extendedInfo
     };
   }

diff --git a/lighthouse-core/audits/time-to-interactive.js b/lighthouse-core/audits/time-to-interactive.js
@@ -120,13 +120,14 @@ class TTIMetric extends Audit {
         const estLatency = latencies[0].time.toFixed(2);
         foundLatencies.push({
           estLatency: estLatency,
-          startTime: startTime.toFixed(1)
+          startTime: parseFloat(startTime.toFixed(1))
         });
 
         // Grab this latency and try the threshold again
         currentLatency = estLatency;
       }
-      const timeToInteractive = parseFloat(startTime.toFixed(1));
+      // The start of our window is our TTI
+      const timeToInteractive = startTime;
 
       // Use the CDF of a log-normal distribution for scoring.
       //   < 1200ms: score≈100
@@ -143,22 +144,22 @@ class TTIMetric extends Audit {
 
       const extendedInfo = {
         timings: {
-          fMP: fmpTiming.toFixed(1),
-          visuallyReady: visuallyReadyTiming.toFixed(1),
-          mainThreadAvail: startTime.toFixed(1)
+          fMP: parseFloat(fmpTiming.toFixed(3)),
+          visuallyReady: parseFloat(visuallyReadyTiming.toFixed(3)),
+          timeToInteractive: parseFloat(startTime.toFixed(3))
         },
         timestamps: {
           fMP: fMPtsInMS * 1000,
           visuallyReady: (visuallyReadyTiming + navStartTsInMS) * 1000,
-          mainThreadAvail: (timeToInteractive + navStartTsInMS) * 1000
+          timeToInteractive: (timeToInteractive + navStartTsInMS) * 1000
         },
         expectedLatencyAtTTI: currentLatency,
         foundLatencies
       };
 
       return TTIMetric.generateAuditResult({
         score,
-        rawValue: timeToInteractive,
+        rawValue: parseFloat(timeToInteractive.toFixed(1)),
         displayValue: `${timeToInteractive}ms`,
         optimalValue: this.meta.optimalValue,
         debugString: speedline.debugString,

diff --git a/lighthouse-core/test/audits/time-to-interactive-test.js b/lighthouse-core/test/audits/time-to-interactive-test.js
@@ -53,8 +53,8 @@ describe('Performance: time-to-interactive audit', () => {
       assert.equal(output.rawValue, '1105.8', output.debugString);
       assert.equal(output.extendedInfo.value.expectedLatencyAtTTI, '20.72');
       assert.equal(output.extendedInfo.value.timings.fMP, '1099.5');
-      assert.equal(output.extendedInfo.value.timings.mainThreadAvail, '1105.8');
-      assert.equal(output.extendedInfo.value.timings.visuallyReady, '1105.8');
+      assert.equal(output.extendedInfo.value.timings.timeToInteractive, 1105.798);
+      assert.equal(output.extendedInfo.value.timings.visuallyReady, 1105.798);
     });
   });
 });