FA-9037 / Undo and history / Member archive

Adjacent typing undo coalescing: Deletion transactions merge as if they were adjacent typing · case 02

Deletion transactions merge as if they were adjacent typing.

Member previewVariant 2 · 3 implementations · 10 checks per implementation

Case contract

Only contiguous insertion edits without explicit boundary coalesce; preserve the first before-state and newest after-state; no-op input creates no history.

Why this case matters

A deterministic model of adjacent typing undo coalescing; 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
delete	`[["abcd", "ab"]]`	`[["abcd", "abc"], ["abc", "ab"]]`	Failed

MEMBER ARCHIVE

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

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