The AMP Project Roadmap

What was accomplished

• v0.js and extensions are now more resilient to double loading of the amp library (https://github.com/ampproject/amphtml/pull/31828)
• fixed module build bug where AMP.require would sometimes not exist (caused by race condition https://github.com/ampproject/amphtml/pull/31988)
• turned down module build to fix p0's
• added bento component generator gulp make-component --bento --name=my-component

Lessons Learned

• separate out test features in isolated PR as they are hard to cherry pick if they are merged with runtime features/additions/removals

What's Next

• unflag module/nomodule in origin

What was accomplished

• IntersectionObserver:
• IntersectionObserver polyfill {root:document} support launched: https://github.com/w3c/IntersectionObserver/pull/465
• Integration updated to select best one on a per-instance basis: https://github.com/ampproject/amphtml/pull/31453
• E2E tests for documentHeight-based viewers (gmail): https://github.com/ampproject/amphtml/pull/31526
• Removed polyfills from esm web-worker, cutting -0.3kb: https://github.com/ampproject/amphtml/pull/31494
• Removed some usages of measuring APIs (https://github.com/ampproject/amphtml/pull/31693, https://github.com/ampproject/amphtml/pull/31730, https://github.com/ampproject/amphtml/pull/31753)
• Holidays! 🎁

Lessons Learned

• Can make empty commits via: git commit --allow-empty -m "Trigger Build"

What's Next

• Continue removing usages of measuring APIs
• Resume compiler research

What was accomplished

• module build rollout is in 100%
• Started privacy & legal reviews for adding CWV metrics from Google AMP cache to Page Experience tool
• exclude iOS < 11 specifically from module build insertion

Lessons Learned

What's Next

• fixes for double exec of module/nomodule in iOS < 11 in the runtime
• Working on APIs for CWV metrics from Google AMP Cache

What was accomplished

• Worked on TDD for adding AMP Cache CWV metrics to Page Experience Tool
• mjs files now need to be approved when increased in size
• build and upload esm tests when integration tests are modified

Lessons Learned

What's Next

• Developing Page Experience Tool rule to ensure placeholder inside amp-img uses only data src (no network requests)
• experiment design doc to have a hold over A/B test for module vs nomodule performance
• Fix bug in Google AMP cache transformer where the document from origin already has module/nomodule pattern in markup

What was accomplished

• Turn on esm tests in travis https://github.com/ampproject/amphtml/pull/28336
• investigated A2HS support, but decided not to pursue further

Lessons Learned

What's Next

• mjs tracking for bundle size bot
• de-flake amp-user-notification tests
• write document for SxG experiment methodology
• ramp module/nomodule to 100%
• investigating new rules for Pixi

What was accomplished

• integration fixture files are now transformed through postHTML
• safari fix for block scoping performance regression (can be 3x to 10x slower)
• Investigated Firefox amp-sidebar FixedLayer bug, turned out to be testing setup misconfiguration (https://github.com/ampproject/amphtml/issues/30819)
• Removing {BaseElement.viewportCallback}: 3 PRs currently in flight, as well as a few merged (https://github.com/ampproject/amphtml/pull/30647, https://github.com/ampproject/amphtml/pull/30802, https://github.com/ampproject/amphtml/pull/30859). One already merged (https://github.com/ampproject/amphtml/pull/30761)
• Various test fixes, including aligning unit tests with prod-config: https://github.com/ampproject/amphtml/pull/30535

Lessons Learned

• function definitions can be recursively redefined. (function f() { f = () => 5; return 7})

What's Next

• esm to 100% (monitoring safari performance)
• esm e2e tests
• continue removing viewportCallback as well as associated code
• research two Dynamic Mail bugs probably related to intersect-resources.

What was accomplished

• fix esm ads performance/query tracking
• make sure to opt-out control of LTS reporting
• correctly cache busted control (this caused control to have higher cache hit rate as it was using production resources)
• make performance-impl more robust in performanceobserver observe calls https://github.com/ampproject/amphtml/pull/30554

Lessons Learned

• do not do a/b testing during the rollout phase and have a separate clean a/b testing environment

What's Next

• esm from 50% to 100%

What was accomplished

• Identified performance bottlenecks with amp.dev including inlined SVGs at top of body, unused CSS (https://github.com/ampproject/amp.dev/issues/4650), unnecessary layers (https://github.com/ampproject/amp.dev/issues/4665), and using custom carousel instead of amp-carousel (https://github.com/ampproject/amp.dev/issues/4670)
• Started build-in-chunks experiment to improve FID (https://github.com/ampproject/amphtml/pull/30301)
• support "mjs" in local/test server routes https://github.com/ampproject/amphtml/pull/30378
• refactor postHTML transformers to support bad or implied localhost URL's (like relative paths) (https://github.com/ampproject/amphtml/pull/30292)
• fix bug in module build for amp-ad's. Transfer the parent document's amp-runtime CSS into the amp-ad friendly iframe (https://github.com/ampproject/amphtml/pull/30257)

Lessons Learned

• web.dev suggests a maximum of 1,500 DOM nodes per page

What's Next

• Continue to identify FID & LCP issues affecting amp.dev (and large AMP sites)
• allow for module/nomodule pattern in JavaScript validator (following c++ changes)

What was accomplished

• fixed AMP deployment of worker-dom artifacts (https://github.com/ampproject/amphtml/pull/30141)
• prototyped moving compilation of worker-dom to downstream repos. (https://github.com/ampproject/worker-dom/pull/937)
• added amp-debug and amp-production binaries to worker-dom. (https://github.com/ampproject/worker-dom/pull/929)
• prototyped adding content-visibility css automatically for valid AMP components.
• created repo to test amp.dev performance and discovered svg issue causing slowdown

Lessons Learned

What's Next

• visual diffs for module build
• improve compatibility of worker-dom Element.innerHTML setter.

What was accomplished

• Removed fine and info level logs from ESM build for additional runtime size reduction
• tested modulepreload vs preload vs modulepreload + preload in tachometer (synthetic testing showing that there is no gain to using modulepreload in chrome)

Lessons Learned

What's Next

• Figure out how to make amp.dev pass CWV
• Study advanced closure optimizations/ global variable renaming (potential size reduction: 5kb)
• Study removing user assertions & errors from ESM build for additional size reduction
• add AMP "browsing stories" to chromium system health
• add in memory object table to fix message extraction race condition on disk

What was accomplished

• exclude LTS from module/nomodule rollout
• added AMP "loading stories" to chromium system health
• finished design doc on AMP Analytics vendor config inlining
• Wrapped up work on the AMP packager for the SxG build
• AMP Animations polyfill to lazyloading saving ~18KB for compliant browsers

Lessons Learned

What's Next

• add AMP "browsing stories" to chromium system health
• work on adding module/nomodule support for validator
• make amp.dev pass CWV
• Begin working on validator changes for the SxG build

What was accomplished

• Merged ads experiment id's for module/nomodule
• runtime type meta is temporarily inserted for module/nomodule ads experiments detection (ex. <meta name="runtime-type" value="${value}">
• @xiexr151e added gulp coverage-map task. allows to evaluate code not ran during initialization

Lessons Learned

What's Next

• evaluate gulp unit testing to align with module build
• fixes/update to gulp coverage-map

What was accomplished

• Add a way for the module/nomodule rollout to be able to identify its control branch. This gives us a path to report to the ads team
• Did some preliminary work on reducing v0.js in the upcoming SxG build by enabling the experiment on fixed layer code

Lessons Learned

What's Next

• Add reporting for rollout of module/nomodule as an ads experiment on client side

What was accomplished

• Merged CSS insert logic for tests https://github.com/ampproject/amphtml/pull/28972
• OpenJS/Web.dev conferences
• Wrapped up server side cache transformation for inline amp-analytics vendor config
• Fixed Transpilation of WorkerDOM impacting Element.classList.
• Moved AMP to Graal Native Closure Compiler, increasing concurrency and dropping developer build times by ~2.5x.

Lessons Learned

• Travis, Github, and CircleCI all use low core count machines for Continuous Integration.

What's Next

• turn on transformers for all integration tests. unblock failing critical tests by skipping and assigning to individual working groups.
• Runtime changes for using inlined amp-analytics vendor config
• Efficiency improvements for Closure Compilation
• Kris goes on paternity leave.