@idealic/poker-engine/src/__tests__/croupier/08-multi-street.test.ts

Poker game engine and hand evaluator

/**
 * @instructions
 * Croupier test suite principles:
 * 1. Verify exact action sequence - each player action must be checked in order using exact index in result.actions
 * 2. Verify state transitions after each significant phase:
 *    - After initial deal: stacks after blinds, street
 *    - After betting round: stacks, roundBet, totalBet, currentBet, pot
 *    - After showdown: board length, shown cards
 * 3. Include detailed pot calculations in comments, showing contributions from each player
 * 4. Use position labels in comments (BTN, SB, BB) to clarify action order
 * 5. Group verifications by game phase (deal, betting, board, final)
 * 6. Avoid array slicing for action verification to ensure strict order
 * 7. Focus on money movement and betting state, avoid implementation details
 * 8. Always verify bettingComplete after each round closes
 * 9. For all-in situations, verify isAllIn status and automatic board dealing
 */

import { Game } from '../../Game';
import { croupier } from '../../game/croupier';
import { Hand } from '../../Hand';

const createPlayers = (histories: string[][]) => {
  return histories.map((history, i) => {
    let index = 0;
    return () => Promise.resolve(history[index++] || `p${i + 1} cc`);
  });
};

/**
 * This test simulates a complex hand with action on all streets and position changes.
 * It's interesting because it:
 * 1. Tests intricate betting patterns across all streets
 * 2. Verifies position-dependent action order changes
 * 3. Ensures proper pot growth through multiple betting rounds
 * 4. Validates complex action closing rules
 * 5. Tests large bet sizing and raise calculations
 */
describe('Croupier - Multi-street Betting', () => {
  it('should handle complex multi-street betting with position changes', async () => {
    const hand: Hand = {
      variant: 'NT',
      players: ['p1', 'p2', 'p3'],
      startingStacks: [1000, 1000, 1000],
      blindsOrStraddles: [0, 10, 20],
      antes: [],
      actions: [],
      minBet: 20,
      seed: 123456,
    };

    const players = createPlayers([
      ['p1 cbr 60', 'p1 cc', 'p1 cbr 200', 'p1 cc'], // BTN: raise preflop, call flop, bet turn, call river
      ['p2 cc', 'p2 cbr 100', 'p2 cc', 'p2 cbr 400'], // SB: call preflop, lead flop, call turn, bet river
      ['p3 cc', 'p3 cc', 'p3 cc', 'p3 cc'], // BB: call preflop, call flop, call turn, call river
    ]);
    const result = await croupier(hand, players);

    let game: Game;

    // Initial deal
    expect(result.actions[0]).toMatch(/^d dh p1/);
    expect(result.actions[1]).toMatch(/^d dh p2/);
    expect(result.actions[2]).toMatch(/^d dh p3/);

    game = Game(hand, result.actions.slice(0, 3));
    expect(game.street).toBe('preflop');
    expect(game.players.map(p => p.stack)).toEqual([1000, 990, 980]);
    expect(game.players.map(p => p.roundBet)).toEqual([0, 10, 20]);
    expect(game.bet).toBe(20);

    // Preflop betting
    expect(result.actions[3]).toBe('p1 cbr 60'); // BTN raises to 60 (+60)

    game = Game(hand, result.actions.slice(0, 4));
    expect(game.players.map(p => p.roundBet)).toEqual([60, 10, 20]);
    expect(game.bet).toBe(60);

    expect(result.actions[4]).toBe('p2 cc'); // SB calls (+50)
    expect(result.actions[5]).toBe('p3 cc'); // BB calls (+40)

    game = Game(hand, result.actions.slice(0, 6));
    expect(game.players.map(p => p.stack)).toEqual([940, 940, 940]);
    expect(game.players.map(p => p.roundBet)).toEqual([60, 60, 60]);
    expect(game.players.map(p => p.totalBet)).toEqual([60, 60, 60]);
    expect(game.isBettingComplete).toBe(true);
    expect(game.bet).toBe(60);
    expect(game.pot).toBe(180); // 60 (BTN) + 60 (SB) + 60 (BB)

    // Flop
    expect(result.actions[6]).toMatch(/^d db/);
    expect(result.actions[7]).toBe('p2 cbr 100'); // SB leads for 100

    game = Game(hand, result.actions.slice(0, 8));
    expect(game.players.map(p => p.roundBet)).toEqual([0, 100, 0]);
    expect(game.bet).toBe(100);

    expect(result.actions[8]).toBe('p3 cc'); // BB calls
    expect(result.actions[9]).toBe('p1 cc'); // BTN calls

    game = Game(hand, result.actions.slice(0, 10));
    expect(game.players.map(p => p.stack)).toEqual([840, 840, 840]);
    expect(game.players.map(p => p.roundBet)).toEqual([100, 100, 100]);
    expect(game.players.map(p => p.totalBet)).toEqual([160, 160, 160]);
    expect(game.isBettingComplete).toBe(true);
    expect(game.bet).toBe(100);
    expect(game.pot).toBe(480); // Preflop (180) + Flop (300)

    // Turn
    expect(result.actions[10]).toMatch(/^d db/);
    expect(result.actions[11]).toBe('p2 cc'); // SB checks
    expect(result.actions[12]).toBe('p3 cc'); // BB checks
    expect(result.actions[13]).toBe('p1 cbr 200'); // BTN bets 200

    game = Game(hand, result.actions.slice(0, 14));
    expect(game.players.map(p => p.roundBet)).toEqual([200, 0, 0]);
    expect(game.bet).toBe(200);

    expect(result.actions[14]).toBe('p2 cbr 400'); // SB raises to 400
    expect(result.actions[15]).toBe('p3 cc'); // BB calls
    expect(result.actions[16]).toBe('p1 cc'); // BTN calls

    game = Game(hand, result.actions.slice(0, 17));
    expect(game.players.map(p => p.stack)).toEqual([440, 440, 440]);
    expect(game.players.map(p => p.roundBet)).toEqual([400, 400, 400]);
    expect(game.players.map(p => p.totalBet)).toEqual([560, 560, 560]);
    expect(game.isBettingComplete).toBe(true);
    expect(game.bet).toBe(400);
    expect(game.pot).toBe(1680); // Previous (480) + Turn (1200)

    // River
    expect(result.actions[17]).toMatch(/^d db/);
    expect(result.actions[18]).toBe('p2 cc'); // SB checks
    expect(result.actions[19]).toBe('p3 cc'); // BB checks
    expect(result.actions[20]).toBe('p1 cc'); // BTN checks

    // Final state
    game = Game(hand, result.actions);
    expect(game.players.map(p => p.stack)).toEqual([440, 2120, 440]); // Each -560 total
    expect(game.players.map(p => p.roundBet)).toEqual([0, 0, 0]); // No betting on river
    expect(game.players.map(p => p.totalBet)).toEqual([560, 560, 560]); // All betting done on turn
    expect(game.players.map(p => p.hasFolded)).toEqual([false, false, false]);
    expect(game.bet).toBe(0);
    expect(game.pot).toBe(1680); // distributed
    expect(game.isBettingComplete).toBe(true);
    expect(game.board).toHaveLength(5); // Full board dealt
    expect(game.players.map(p => p.hasShownCards)).toEqual([true, true, true]); // All show in multi-way pot
  });
});