FA-7944 / Selection controls / Member archive

Hierarchical checkbox state: Clicking a checked child cannot deselect it · case 04

Clicking a checked child cannot deselect it.

Member previewVariant 4 · 3 implementations · 11 checks per implementation

Case contract

Subtree actions preserve outside selections; toggle is symmetric; parent status depends only on selected descendants and distinguishes none, mixed and all.

Why this case matters

A deterministic model of hierarchical checkbox state; 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
toggle off	`[["a"], "mixed"]`	`[[], "none"]`	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.