boardgame-core/tests/core/part.test.ts

import { describe, it, expect } from 'vitest';
import { flip, flipTo, roll, Part } from '@/core/part';
import { createRNG } from '@/utils/rng';

function createTestPart<TMeta = {}>(overrides: Partial<Part<TMeta>> & TMeta): Part<TMeta> {
  return {
    id: 'test-part',
    regionId: 'test-region',
    position: [0, 0],
    ...overrides,
  } as Part<TMeta>;
}

describe('flip', () => {
  it('should cycle to next side when sides is defined', () => {
    const part = createTestPart({ sides: 2, side: 0 });
    flip(part);
    expect(part.side).toBe(1);
    flip(part);
    expect(part.side).toBe(0);
  });

  it('should wrap around when side reaches sides count', () => {
    const part = createTestPart({ sides: 6, side: 5 });
    flip(part);
    expect(part.side).toBe(0);
  });

  it('should do nothing when sides is undefined', () => {
    const part = createTestPart({ side: 3 });
    flip(part);
    expect(part.side).toBe(3);
  });

  it('should initialize side to 0 when side is undefined', () => {
    const part = createTestPart({ sides: 4 });
    flip(part);
    expect(part.side).toBe(1);
  });
});

describe('flipTo', () => {
  it('should set side to specified value', () => {
    const part = createTestPart({ sides: 6, side: 0 });
    flipTo(part, 3);
    expect(part.side).toBe(3);
  });

  it('should do nothing when sides is undefined', () => {
    const part = createTestPart({ side: 2 });
    flipTo(part, 5);
    expect(part.side).toBe(2);
  });

  it('should do nothing when side exceeds sides count', () => {
    const part = createTestPart({ sides: 6, side: 0 });
    flipTo(part, 6);
    expect(part.side).toBe(0);
  });

  it('should allow side equal to sides - 1', () => {
    const part = createTestPart({ sides: 6, side: 0 });
    flipTo(part, 5);
    expect(part.side).toBe(5);
  });
});

describe('roll', () => {
  it('should randomize side when sides is defined', () => {
    const part = createTestPart({ sides: 6 });
    const rng = createRNG(12345);
    roll(part, rng);
    expect(part.side).toBeGreaterThanOrEqual(0);
    expect(part.side).toBeLessThan(6);
  });

  it('should do nothing when sides is undefined', () => {
    const part = createTestPart({ side: 3 });
    const rng = createRNG(12345);
    roll(part, rng);
    expect(part.side).toBe(3);
  });

  it('should produce deterministic results with same seed', () => {
    const part1 = createTestPart({ sides: 6 });
    const part2 = createTestPart({ sides: 6 });
    const rng1 = createRNG(42);
    const rng2 = createRNG(42);
    roll(part1, rng1);
    roll(part2, rng2);
    expect(part1.side).toBe(part2.side);
  });
});