History/server/map.test.ts

import { describe, expect, it } from 'vitest';
import { buildRegionMap } from './map';
import { mapFeatureOwner, nationColor, regionOwner, type RegionMap } from '../shared/protocol';
import type { GameState } from '../shared/types';

// As of v0.19 territory is a list of **sub-region ids** (the RegionMap keys),
// not whole-country ISO_A3 codes.
const state: GameState = {
  id: 'g',
  presetId: 'p',
  presetTitle: 'P',
  playerNationId: 'uk',
  turn: 1,
  date: '1939-09-01',
  nations: {
    uk: {
      id: 'uk',
      name: 'UK',
      type: 'major',
      stats: { military: 80, economy: 70, stability: 60, population: 50 },
      territory: ['GB-01', 'GB-02'],
      relations: {},
    },
    de: {
      id: 'de',
      name: 'DE',
      type: 'major',
      stats: { military: 90, economy: 70, stability: 70, population: 90 },
      territory: ['DE-01'],
      relations: {},
    },
  },
  events: [],
  pending: [],
  version: 1,
};

// The RegionMap built from the fixture: the authoritative sub-region id → owner
// source.
const regions: RegionMap = buildRegionMap(state);

describe('buildRegionMap', () => {
  it('maps each sub-region id to its owner + that nation\'s stable color', () => {
    const m = buildRegionMap(state);
    expect(m['GB-01']).toEqual({ color: nationColor('uk'), owner: 'UK', ownerId: 'uk' });
    expect(m['GB-02']).toEqual({ color: nationColor('uk'), owner: 'UK', ownerId: 'uk' });
    expect(m['DE-01']).toEqual({ color: nationColor('de'), owner: 'DE', ownerId: 'de' });
    // a sub-region nobody owns is simply absent
    expect(m['FR-57']).toBeUndefined();
  });
});

describe('regionOwner', () => {
  it('resolves an owned sub-region id to its owner record', () => {
    expect(regionOwner(regions, 'GB-01')).toEqual({
      color: nationColor('uk'),
      owner: 'UK',
      ownerId: 'uk',
    });
    expect(regionOwner(regions, 'DE-01')).toEqual({
      color: nationColor('de'),
      owner: 'DE',
      ownerId: 'de',
    });
  });

  it('returns undefined for an unowned region (no RegionMap entry)', () => {
    expect(regionOwner(regions, 'FR-57')).toBeUndefined();
    expect(regionOwner(regions, 'US-01')).toBeUndefined();
  });

  it('returns undefined for an empty or missing id', () => {
    expect(regionOwner(regions, '')).toBeUndefined();
    expect(regionOwner(regions, null)).toBeUndefined();
    expect(regionOwner(regions, undefined)).toBeUndefined();
  });
});

/**
 * #6 regression guard (sub-national map, v0.19 region-level ownership). The
 * click/hover handlers resolve the owning nation from a rendered map feature.
 * MapLibre repacks a GeoJSON source's top-level `id` into a *numeric index*
 * when it stores the source, so a feature the map hands back at interaction
 * time has a number for `id`. Since v0.19 ownership is at **sub-region**
 * granularity: a feature's owner lives at its **own sub-region id** (e.g.
 * `DE-01`), which the client stamps into `properties.regionId` (the RegionMap
 * is keyed by that id). This pins the exact data shape and proves the
 * resolution: `mapFeatureOwner` works via `properties.regionId`, while the
 * repacked numeric `feature.id` path does not.
 */
describe('#6 — region owner must be resolved from properties.regionId, never the repacked feature.id', () => {
  // The shape MapLibre returns for a sub-region feature after setData(): `id`
  // is a number (repacked), and the stable identifiers live only in properties
  // — `regionId` (the sub-region id, the RegionMap key) and `parent` (the
  // static parent country's ISO_A3).
  const repackedFeature = {
    id: 0,
    properties: { name: 'Rhineland', regionId: 'DE-01', parent: 'DEU' },
  };

  it('resolves the owner from properties.regionId (the fix)', () => {
    expect(mapFeatureOwner(regions, repackedFeature)).toEqual({
      color: nationColor('de'),
      owner: 'DE',
      ownerId: 'de',
    });
  });

  it('the repacked numeric feature.id does NOT resolve — the original bug', () => {
    // String(0) === '0' is not a valid key, so the pre-fix lookup failed and
    // reported "No owner" even for owned regions.
    expect(regionOwner(regions, String(repackedFeature.id))).toBeUndefined();
  });

  it('a sub-region id nobody owns does NOT resolve', () => {
    expect(regionOwner(regions, 'FR-57')).toBeUndefined();
  });
});

describe('mapFeatureOwner', () => {
  it('returns undefined for a missing feature, missing regionId, or non-string regionId', () => {
    expect(mapFeatureOwner(regions, null)).toBeUndefined();
    expect(mapFeatureOwner(regions, undefined)).toBeUndefined();
    expect(mapFeatureOwner(regions, {})).toBeUndefined();
    expect(mapFeatureOwner(regions, { properties: {} })).toBeUndefined();
    expect(mapFeatureOwner(regions, { properties: { regionId: 42 } })).toBeUndefined();
    expect(mapFeatureOwner(regions, { properties: { regionId: '' } })).toBeUndefined();
  });

  it('returns undefined for a sub-region nobody owns', () => {
    expect(mapFeatureOwner(regions, { properties: { regionId: 'FR-57' } })).toBeUndefined();
    expect(mapFeatureOwner(regions, { properties: { regionId: 'US-01' } })).toBeUndefined();
  });
});

describe('nationColor', () => {
  it('is deterministic per id and distinct across different ids', () => {
    expect(nationColor('uk')).toBe(nationColor('uk'));
    expect(nationColor('uk')).not.toBe(nationColor('de'));
    // always a valid HSL string
    expect(nationColor('uk')).toMatch(/^hsl\(\d+ 58% 46%\)$/);
  });
});