FA-82368 / Chess move legality / Member archive

Slider x-rays through an enemy piece · case 03

A rook facing an enemy pawn is offered the squares behind it, including the enemy king square.

Member previewVariant 3 · 3 implementations · 8 checks per implementation

Case contract

Input: {"board", "from": square of a rook, bishop or queen}. Return the sorted pseudo-legal destinations: walk each ray until the edge; an empty square is added, an enemy piece is added and ends the ray, a friendly piece ends the ray without being added.

Why this case matters

Move validators gate every move in engines, servers and arbiters; accepting an illegal move or rejecting a legal one corrupts the game record.

One recorded failure

Sample boundary fixture

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

Boundary fixture	Actual	Expected	Outcome
rook blocked by enemy	`["a2", "a3", "a4", "a5", "a6", "a7", "a8", "b1"]`	`["a2", "a3", "b1"]`	Failed

MEMBER ARCHIVE

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

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