☂️ Breaking changes for v9

[adamraine]

• https://github.com/GoogleChrome/lighthouse/issues?q=label%3A9.0+
• Remove redirects-http core: remove the redirect pass and redirects-http audit #12643
• Remove appcache - as of m95, appcache is gone. no more OT that kept it alive. core(appcache-manifest): remove audit #13287
• Remove preload audits based on Preload suggestions are too aggressive #11960 (likely needs more investigation based on pmeenan's recent preload improvements - one option is to remove from default config for v9 (rather than keep as N/A that just sit there)).
• Remove mimeType from ImageElements gatherer core(image-elements): remove mimeType from artifact #13265
• remove url prop in errors-in-console details core(errors-in-console): remove url property from items #13286
• Remove PWA category gauge function alias report(pwa): remove gauge alias #13269
• visual indicator of mobile/desktop on perf score - Add visual indicator to score to warn when it was run with non-default settings #8178
• report api proposal: report api #12772

Punted from v8

• move to minimum Node 14 · deps: move to minimum Node 14 #13243

Previously: v8.0 burndown

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Punting

• possibly recalibrate throttling multipliers · Improve BenchmarkIndex to land device targeting #9085
• redirects performance consistency observed v. simulated · Improve handling of redirects, navStart #8984
• Require supportedModes in audits core(fr): add audit mode filter #12649
• Mark BenchmarkIndex optional, remove in snapshot mode / repeated flow situations (we lost context for motivation for this. seems ok but not important)
• drop TagsBlockingFirstPaint gatherer and base render-blocking-resources on LinkElements and ScriptElements instead · misc: add type checking to TagsBlockingFirstPaint #11841 (comment)? probably pending decision on AMP special handling.
  • Also perhaps instead: we use the render-blocking signal from trace events (TODO find issue)

[lifeart]

Note for:

• possibly recalibrate throttling multipliers · Improve BenchmarkIndex to land device targeting #9085

Modern CPU's has different perf-boost techniques, like TurboBoost, and it may temporary improve performance up to 30+%, and "second" measurement can catch performance decrease, because of "cooling" CPU policy.

Also, performance may be different, depends on selected power plan (Windows)

[connorjclark]

Last 8.x release is ~Oct 12

[adamraine]

Merge HostUserAgent and HostFormFactor core(fr): convert additional base artifacts #12594 (comment)

This was added as a breaking change back when HostUserAgent and HostFormFactor had their own gatherers. I'm ok cancelling this idea now that we changed them back to base artifacts.