FA-39188 / Tree accessibility / Member archive

Treegrid rectangular cell range: Cell range extension mutates its anchor · case 03

Cell range extension mutates its anchor produces the wrong hierarchical widget state in a regression fixture.

Member previewVariant 3 · 3 implementations · 6 checks per implementation

Case contract

A cell range spans visible rows within the anchor sibling group and visible columns; collapsed descendants and other sibling groups are excluded. Disabled rows and protected cells are skipped. Range serialization follows row-major visible order; additive range preserves prior cells.

Why this case matters

Offline executable model of a hierarchical accessibility interaction; inputs are bounded and valid as stipulated. No browser, assistive technology, or normative ARIA conformance is claimed.

One recorded failure

Sample boundary fixture

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

Boundary fixture	Actual	Expected	Outcome
rectangle	`[["a:name", "a:x", "a:y", "c:name", "c:y", "d:name", "d:x", "d:y"], "d:y", ["d", "y"]]`	`[["a:name", "a:x", "a:y", "c:name", "c:y", "d:name", "d:x", "d:y"], "d:y", ["a", "name"]]`	Failed

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

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