[Website] Fix service worker cache purging to support multi-tab scenarios#3414
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brandonpayton wants to merge 4 commits intotrunkfrom
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[Website] Fix service worker cache purging to support multi-tab scenarios#3414brandonpayton wants to merge 4 commits intotrunkfrom
brandonpayton wants to merge 4 commits intotrunkfrom
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self.serviceWorker.state has been available in Firefox since v120 (Nov 2023). Update the misleading comment and make the @ts-ignore annotation more descriptive. The guard is kept as a safety net.
After a service worker update, old tabs still hold references to hashed asset URLs from the previous build. These assets are gone from the current cache and the server, causing 404s and "Failed to initialize WordPress" errors. Search all previous playground-cache-* caches before going to the network so old tabs can still find their assets. Also add purgeExcessOldCaches() which keeps the most recent old cache instead of purging everything, bounding storage to ~3 versions.
Switch from purgeEverythingFromPreviousRelease() to purgeExcessOldCaches() so old tabs can still resolve their hashed asset URLs from the previous build's cache.
brandonpayton
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I'm not sure what I think about this yet but would like to explore it.
| // hashed asset URLs from the previous build. Search older | ||
| // caches before going to the network so those tabs don't 404. | ||
| const previousVersionResponse = await matchInPreviousVersionCaches(request); | ||
| if (previousVersionResponse) { |
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I'm not sure if all packages produce a hashed filename. I have a vague memory of at least one exception to the name-with-hash approach, but it might have been for Node.js deps consumed by Studio builds. We need to make sure.
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| // Keep the last entry (typically the most recent old cache) | ||
| // and delete the rest. | ||
| const toDelete = oldNames.slice(0, -1); |
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It's a bit weak to depend up on the last being "typically the most recent". We need to look more closely at this.
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The test was skipped because it used an outdated UI flow (the "Add Playground" modal no longer exists). Rewrite the test to create a new site via URL query parameters instead, which is the current pattern for specifying WordPress version and language.
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Summary
cacheFirstFetchnow falls back toprevious-version
playground-cache-*caches before going to thenetwork, so old tabs can still resolve their hashed asset URLs
purgeExcessOldCaches()instead ofpurgeEverythingFromPreviousRelease(), keeping the most recent oldcache (bounded to ~3 versions total)
this issue
Problem
When a new version of Playground is deployed, the service worker
immediately activates (
skipWaiting()) and purges all old cachedassets. Existing browser tabs still hold references to old hashed asset
URLs (e.g.,
php_8_3-2286e20c.js). These assets are gone from bothcache and server, causing 404s and "Failed to initialize WordPress"
errors.
This particularly affects users with multiple Playground tabs open
during a deploy.
Approach
Two complementary changes:
Fallback cache search:
cacheFirstFetchchecks all olderplayground-cache-*caches after a miss in the current build'scache, before going to the network. This lets old tabs find their
hashed assets in the previous version's cache.
Retain one old cache:
purgeExcessOldCaches()replaces theprevious purge-everything behavior. It keeps the most recent old
cache and deletes the rest, so old tabs have somewhere to find their
assets. The surviving cache gets cleaned up on the next deploy.
Only the cache-first path needs the fallback —
networkFirstFetch(used for
remote.htmland/) already fetches fresh content.Test plan
npx nx test playground-remotepassesnpx nx lint playground-remotepassesnpx nx e2e playground-website— deployment tests, including there-enabled multi-tab test
the first tab doesn't crash