Fix live graph never rendering (Infinity sample poisons maxValue) - #167
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claudioabreu wants to merge 1 commit into
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Fix live graph never rendering (Infinity sample poisons maxValue)#167claudioabreu wants to merge 1 commit into
claudioabreu wants to merge 1 commit into
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At the very start of a measurement the elapsed time can be ~0, so the first speed sample (dTotal/dtTotal) evaluates to Infinity. isNaN(Infinity) is false, so the sample enters values[] and maxValue stays Infinity for the whole test: every point of the live graph collapses to y=height (invisible polygon) and calcPoints produces NaN coordinates (SVG errors in the console). Fix: only accept finite samples in Graph(), and guard the perc division in calcPoints. Applied to both app-2.5.4.js and app-2.5.4.min.js.
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Problem
The live traffic graph inside the result cards never renders, and the console shows SVG errors like
Error: <polygon> attribute points: Expected number, "… NaN …".Root cause: at the very start of a measurement the elapsed time is ~0, so the first speed sample (
dTotal/dtTotal) evaluates toInfinity.isNaN(Infinity)isfalse, so the sample entersvalues[]andmaxValuestaysInfinityfor the entire test — every subsequent point ofcalcPoints()collapses toy = height(an invisible polygon along the baseline), andInfinity/Infinityproduces theNaNcoordinates seen in the console.Fix
Graph(): only accept finite samples (!isNaN(speed) && isFinite(speed));calcPoints(): guard thevalues[x]/maxValuedivision (isFinite(perc) || (perc = 0)).Applied to both
app-2.5.4.jsandapp-2.5.4.min.js(same logic, minified form).How to reproduce / validate
Run any speed test and watch the graphs in the result cards: before this patch they stay empty and the console logs the polygon/NaN error on every tick; after it, the download/upload graphs draw live and persist after the test.
Found while maintaining our fork (vialink/vialink-speedtest) — running in production with this fix since June 2026.