FA-82367 / Chess move legality / Member archive

Slider x-rays through an enemy piece · case 02

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

Member previewVariant 2 · 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 behind enemy	`["a4", "b4", "c4", "d1", "d2", "d3", "d5", "d6", "d7", "d8", "e4"]`	`["b4", "c4", "d1", "d2", "d3", "d5", "d6", "e4"]`	Failed

MEMBER ARCHIVE

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

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