FA-8404 / Tree accessibility / Member archive

Tree keyboard expansion: Collapse-all leaves unrelated expanded branches open · case 04

Collapse-all leaves unrelated expanded branches open.

Member previewVariant 4 · 3 implementations · 11 checks per implementation

Case contract

Right expands then enters the first child; Left collapses only the current branch or focuses its parent; roots retain focus; collapse-all clears every expansion.

Why this case matters

A deterministic model of tree keyboard expansion; this isolates one interface invariant without requiring a browser.

One recorded failure

Sample boundary fixture

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

Boundary fixture	Actual	Expected	Outcome
all	`["a", ["z"]]`	`["a", []]`	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.