FA-8228 / Direct manipulation / Member archive

Drag-and-drop list reordering: Drop-after inserts before the target · case 03

Drop-after inserts before the target.

Member previewVariant 3 · 3 implementations · 9 checks per implementation

Case contract

Cancellation, missing endpoints and self drops preserve order; otherwise remove the source and insert it immediately before or after the surviving target.

Why this case matters

A deterministic model of drag-and-drop list reordering; 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
after	`["b", "a", "c"]`	`["b", "c", "a"]`	Failed

MEMBER ARCHIVE

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

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