feat(shared): pure phantom-model helpers (seed positions, deserialize)

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-05-18 20:20:46 -04:00
parent 783d85a40c
commit a574100e25
3 changed files with 80 additions and 0 deletions
@@ -0,0 +1,38 @@
+import { describe, it, expect } from 'vitest';
+import { opponentStartPosition, deserializePhantoms } from '../src/phantoms.js';
+
+describe('opponentStartPosition', () => {
+  it('seeds 16 black pieces on ranks 7-8', () => {
+    const p = opponentStartPosition('b');
+    expect(Object.keys(p).length).toBe(16);
+    expect(p.e8).toEqual({ color: 'b', type: 'k' });
+    expect(p.d8).toEqual({ color: 'b', type: 'q' });
+    expect(p.a8).toEqual({ color: 'b', type: 'r' });
+    expect(p.h7).toEqual({ color: 'b', type: 'p' });
+  });
+
+  it('seeds 16 white pieces on ranks 1-2', () => {
+    const p = opponentStartPosition('w');
+    expect(Object.keys(p).length).toBe(16);
+    expect(p.e1).toEqual({ color: 'w', type: 'k' });
+    expect(p.a2).toEqual({ color: 'w', type: 'p' });
+  });
+});
+
+describe('deserializePhantoms', () => {
+  it('returns {} for null or invalid JSON', () => {
+    expect(deserializePhantoms(null)).toEqual({});
+    expect(deserializePhantoms('not json')).toEqual({});
+    expect(deserializePhantoms('[]')).toEqual({});
+  });
+
+  it('keeps valid entries and drops invalid ones', () => {
+    const raw = JSON.stringify({
+      e5: { color: 'b', type: 'n' },
+      zz: { color: 'b', type: 'p' },  // invalid square
+      a1: { color: 'x', type: 'p' },  // invalid colour
+      b2: { color: 'b', type: 'z' },  // invalid type
+    });
+    expect(deserializePhantoms(raw)).toEqual({ e5: { color: 'b', type: 'n' } });
+  });
+});