GoogleChrome/lighthouse-ci

CLS diff not showing on compare screen

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#689 opened on Sep 13, 2021

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buggood first issue

Description

Describe the bug I have 2 builds with different CLS Build 1 - CLS = 0.001 Build 2 - CLS = 0.026 When I compare this 2 builds it will not show CLS in metrics (this works with any threshold)

To Reproduce Steps to reproduce the behavior:

  1. Prepare 2 builds with different CLS
  2. Compare them

Expected behavior See CLS diff same way as any other metrics.

Logs/Screenshots I think it's clear w/o any screenshots

Environment (please complete the following information):

  • Server - latest docker server
  • Client - latest docker client

Contributor guide

Tech stack
javascriptnodejs
Domain
frontendperformance
Issue type
bug
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
3
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
1-3 hours
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
stale
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
clear
Prerequisites
Familiarity with Lighthouse metricsBasic understanding of Node.js
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
60
Research direction
Start by examining the compare screen component in the Lighthouse CI server code (likely in the 'server' directory). Look for how metrics are filtered or displayed, especially around CLS. Review the logic that determines which metrics show up in the comparison view. Check if CLS is being ignored due to a missing case or a bug in metric key handling. Also, read through the issue comments for any hints or partial solutions.