FA-54832 / Accessibility interaction semantics / Member archive

Equal-stack semantic objects reverse native encounter precedence · case 02

Equal-stack semantic objects reverse native encounter precedence.

Member previewVariant 2 · 3 implementations · 8 checks per implementation

Case contract

Input [window_origin,scroll,point,records,expected_window]. Pointer is screen coordinates. Convert to document coordinates by subtracting window_origin and adding scroll. Records [id,window,rect,z,exposed,transparent,clip,proxy,enabled]; rect and optional clip are [x0,y0,x1,y1], half-open. Zero/reversed rectangles never hit. Reject other windows or unexposed records. Transparent records do not themselves hit. Reject points outside clip. Among hits largest z wins, ties retain first input. Disabled semantics remain inspectable. Return proxy ID when nonempty, else own ID, plus [document_x,document_y]. None when no hit. This is semantic hit selection, not pixel rendering or focus navigation.

Why this case matters

Offline accessibility bridge model with explicit policy; useful for testing semantic API adapters independently of browser implementations.

One recorded failure

Sample boundary fixture

This sample comes from the broken implementation of a controlled reproducer.

Boundary fixture	Actual	Expected	Outcome
contract fixture 3	`["second", [1, 1]]`	`["first", [1, 1]]`	Failed

MEMBER ARCHIVE

The complete case is available to members.

This record includes three runnable implementations, regression fixtures, execution results, and source hashes.

Member access is invitation-based. Sign in with your invited account to inspect the sources.