feat: implement legal castling #1

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Janis merged 12 commits from castling into main 2026-03-24 17:55:01 +01:00

Conversation 1 Commits 12 Files Changed 12

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lq64 commented 2026-03-24 17:05:36 +01:00

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Summary

• Introduces GameContext wrapper (board + castling rights) threading through the entire engine pipeline
• Extends MoveValidator with castlingTargets, context-aware legalTargets/isLegal overloads, and helpers (isCastle, castleSide)
• Updates GameRules.legalMoves and gameStatus to use GameContext, preventing false stalemate when castling is the only legal move
• Adds castle detection and atomic execution (withCastle) to GameController.processMove, plus full rights revocation via source- and
  destination-square tables

Test Plan

• 142 tests passing, 100% statement and branch coverage on modules/core
• White/Black kingside (e1g1/e8g8) and queenside (e1c1/e8c8) castling moves execute correctly
• All six legality conditions enforced (rights flags, home squares, empty transit, king not in check, transit/landing squares not attacked)
• Rights revoked on king moves, own rook moves, castle moves, and enemy rook captures
• False stalemate correctly prevented when castling is the only escape

## Summary - Introduces `GameContext` wrapper (board + castling rights) threading through the entire engine pipeline - Extends `MoveValidator` with `castlingTargets`, context-aware `legalTargets`/`isLegal` overloads, and helpers (`isCastle`, `castleSide`) - Updates `GameRules.legalMoves` and `gameStatus` to use `GameContext`, preventing false stalemate when castling is the only legal move - Adds castle detection and atomic execution (`withCastle`) to `GameController.processMove`, plus full rights revocation via source- and destination-square tables ## Test Plan - [ ] 142 tests passing, 100% statement and branch coverage on `modules/core` - [ ] White/Black kingside (e1g1/e8g8) and queenside (e1c1/e8c8) castling moves execute correctly - [ ] All six legality conditions enforced (rights flags, home squares, empty transit, king not in check, transit/landing squares not attacked) - [ ] Rights revoked on king moves, own rook moves, castle moves, and enemy rook captures - [ ] False stalemate correctly prevented when castling is the only escape

lq64 added 11 commits 2026-03-24 17:05:37 +01:00

docs: add castling design spec ... b6ab8ed6ac

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

docs: update castling design spec (rev 2 — spec review fixes) ... 205ade8d88

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

docs: add castling implementation plan (TDD, 9 tasks) ... 38a68549f5

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

feat: add GameContext, CastleSide, and Board.withCastle ... 3c8297e1c3

Introduces GameContext (board + per-side CastlingRights), CastleSide enum,
and a Board.withCastle extension method. Also pins missing verification
checksums for com.fasterxml:oss-parent:41 and org.junit:junit-bom:5.9.2.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

feat: add castling logic to MoveValidator (castlingTargets + context-aware overloads) ... ffe663a62e

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

refactor: migrate GameRules.legalMoves signature to GameContext ... 7c568581a7

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

feat: include castling moves in GameRules.legalMoves ... 417a475d84

Switch legalMoves to the context-aware MoveValidator.legalTargets(ctx, from)
so castling destinations are included, and simulate castle moves via withCastle
when filtering for self-check.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

feat: migrate GameRules.gameStatus to GameContext; add false-stalemate test ... c9a59d3ad1

- gameStatus now accepts GameContext instead of Board so legalMoves
  (which already requires GameContext for castling) is called directly
  without discarding castling rights
- All four existing gameStatus call sites in GameRulesTest migrated to ctx(...)
- New test: castling as sole legal move returns Normal, not Drawn
- GameController.processMove updated to wrap newBoard in GameContext at
  the gameStatus call site (full ctx propagation deferred to Task 6)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

refactor: migrate GameController to GameContext (signatures only) ... 62e180c6d9

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

feat: add castling execution to processMove ... 150e78e080

Detect castle moves via MoveValidator.isCastle and dispatch to
Board.withCastle so both king and rook are moved atomically.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

feat: add castling rights revocation to processMove ... b0141d2c89

Introduces applyRightsRevocation helper that revokes rights on castle
moves, king/rook departures from home squares, and enemy captures on
rook home squares. Six new tests verify all revocation paths.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Janis approved these changes 2026-03-24 17:36:29 +01:00

Janis added 1 commit 2026-03-24 17:46:03 +01:00

chore: Merge remote-tracking branch 'origin/main' into castling 4a7813f4ff

Janis merged commit 00d326c1ba into main 2026-03-24 17:55:01 +01:00

Janis deleted branch castling 2026-03-24 17:55:01 +01:00

Janis referenced this issue from a commit 2026-03-24 17:55:02 +01:00

feat: implement legal castling (#1)

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Reference: NowChess/NowChessSystems#1