[cowboyd]

Force align test sources with upstream WPT

While implementing DOM features I noticed the coding agent engaging in the following pathological behaviors:

1. changing the WPT tests in order to accomodate a feature I was adding to the DOM, and allowing it to drift from upstream.
2. Writing its own test cases outside the WPT suite for behavior that was explicitly covered by the WPT
3. Not being sure what exactly each WPT test was supposed to cover.

This adds stricter guardrails around what is allowed in the WPT and instructs future agents to respect them. It stipulates that every adapted test file must mirror its upstream path under src/wpt, with .ts appended. The suite shares the revision in packages/web-platform-tests/WPT_REVISION. This allows agents to quickly navigate to the source of the test.

Furthermore, it strengthens the language to say that the upstream WPT should be followed very closely when adding new tests, or implementing functionality.

Then, I had it re-sync with the upstream WPT and ended up with a test suite that is much more faithful to the original implementation. In fact, it got me thinking that once we have HTML parsing as part of our functionality, we can switch to use the upstream tests directly via vendoring or via a git submodule.

Replaces feature prerequisite gates with optional wpt.config.ts selection by upstream source path and case name. Global bindings also live in wpt.config.ts, as an object or a factory for each fresh document. All adapted cases run by default; explicit includes override exclusions. The UI configuration on this base branch explicitly excludes every adapted top-level directory until implementation PRs enable their cases.

[pkg-pr-new]

Open in StackBlitz

npm i https://pkg.pr.new/bombshell-dev/ui/@clack/ui@52

commit: b99c5e6

[codspeed]

Merging this PR will not alter performance

✅ 240 untouched benchmarks

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_{Comparing wpt-suite-fixes (b99c5e6) with main (37ff5d1)}