JSDOM recursion fix

[charlesverge]

Summary

• capture the browser platform's Element#matches implementation once, before nwsapi can replace it
• prevent CommonJS and headless environments from dynamically delegating back through a module-backed node.matches
• add Jest regression coverage for all affected display-state pseudo-classes
• update GitHub Actions to run the Jest suite with the latest Node.js release and current action versions

Problem

The native display-state detection introduced in nwsapi 2.2.26 assumes that node.matches is a native browser implementation when _matches is unavailable. In environments such as jsdom, Element#matches delegates back to the same nwsapi instance:

element.matches(':modal')
-> nwsapi.match(':modal')
-> isModal()
-> matchesNative(':modal')
-> element.matches(':modal')
-> ...

The resulting stack overflow is caught by matchesNative(), so the caller eventually receives false, but only after substantial recursive work and CPU usage.

Solution

Native matcher provenance is now established when the factory is created:

• the browser bootstrap captures the platform matcher from Element.prototype
• the captured matcher is passed into the nwsapi factory and retained in its closure
• matchesNative() calls only that trusted reference
• when no platform matcher is supplied, matchesNative() is initialized as a direct false-returning function

The helper no longer probes node.matches or its vendor-prefixed aliases during selector evaluation. A module-backed matcher therefore cannot be mistaken for a native implementation and called recursively.

CommonJS and headless embedders with a genuine platform matcher can supply it explicitly. Otherwise, nwsapi uses its existing observable DOM-state fallbacks.

Why This Approach

A synchronous re-entrancy flag limits the recursion but still calls the module-backed matcher once for every outer state check. That causes an unnecessary round trip through the host and another nwsapi selector evaluation. It also adds repeated matcher discovery and mutable guard state to a hot path.

Capturing matcher provenance once removes the recursive route entirely:

• zero calls to a module-backed Element#matches
• no repeated matcher-chain lookup
• no try/finally re-entrancy bookkeeping
• no factory-wide flag that can suppress unrelated nested native matching
• one direct call when a trusted platform matcher is available

Testing

The Jest regression suite verifies that:

• module-backed Element#matches is never called for :open, :closed, :modal, :fullscreen, :picture-in-picture, or :popover-open
• an explicitly supplied platform matcher is called exactly once
• an element-level matcher is not consulted when a platform matcher was captured
• exceptions from the platform matcher retain the existing false fallback

Validation performed:

npm test
Test Suites: 1 passed, 1 total
Tests:       3 passed, 3 total

The original jsdom 26.1.0 reproduction also completes without recursion.

CI

The Node workflow now:

• runs on pushes and pull requests targeting the repository's master branch
• uses actions/checkout@v7 and actions/setup-node@v7
• resolves the latest available Node.js release
• installs dependencies and executes npm test