Add Vitest test suite with 184 tests covering all game engine systems

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

packages/game-engine/src/__test-utils__/createTestState.ts

@@ -0,0 +1,68 @@
+import type { GameState } from '@ai-tycoon/shared';
+import {
+  INITIAL_SETTINGS, SAVE_VERSION,
+  INITIAL_ECONOMY, INITIAL_INFRASTRUCTURE, INITIAL_COMPUTE,
+  INITIAL_RESEARCH, INITIAL_MODELS, INITIAL_MARKET,
+  INITIAL_COMPETITORS, INITIAL_TALENT, INITIAL_DATA,
+  INITIAL_REPUTATION, INITIAL_ACHIEVEMENTS,
+} from '@ai-tycoon/shared';
+
+export type DeepPartial<T> = T extends object
+  ? { [K in keyof T]?: DeepPartial<T[K]> }
+  : T;
+
+function deepMerge<T>(target: T, source: DeepPartial<T>): T {
+  if (source === undefined || source === null) return target;
+  if (typeof target !== 'object' || target === null) return source as T;
+  if (Array.isArray(source)) return source as unknown as T;
+
+  const result = { ...target };
+  for (const key of Object.keys(source) as (keyof T)[]) {
+    const srcVal = source[key];
+    if (srcVal === undefined) continue;
+    const tgtVal = result[key];
+    if (
+      typeof tgtVal === 'object' && tgtVal !== null && !Array.isArray(tgtVal) &&
+      typeof srcVal === 'object' && srcVal !== null && !Array.isArray(srcVal)
+    ) {
+      result[key] = deepMerge(tgtVal, srcVal as DeepPartial<typeof tgtVal>);
+    } else {
+      result[key] = srcVal as T[keyof T];
+    }
+  }
+  return result;
+}
+
+function baseState(): GameState {
+  return {
+    meta: {
+      saveVersion: SAVE_VERSION,
+      companyName: 'TestCorp',
+      currentEra: 'startup',
+      tickCount: 0,
+      lastTickTimestamp: Date.now(),
+      gameSpeed: 1,
+      isPaused: false,
+      createdAt: Date.now(),
+      totalPlayTime: 0,
+      settings: { ...INITIAL_SETTINGS },
+    },
+    economy: structuredClone(INITIAL_ECONOMY),
+    infrastructure: structuredClone(INITIAL_INFRASTRUCTURE),
+    compute: structuredClone(INITIAL_COMPUTE),
+    research: structuredClone(INITIAL_RESEARCH),
+    models: structuredClone(INITIAL_MODELS),
+    market: structuredClone(INITIAL_MARKET),
+    competitors: structuredClone(INITIAL_COMPETITORS),
+    talent: structuredClone(INITIAL_TALENT),
+    data: structuredClone(INITIAL_DATA),
+    reputation: structuredClone(INITIAL_REPUTATION),
+    achievements: structuredClone(INITIAL_ACHIEVEMENTS),
+  };
+}
+
+export function createTestState(overrides?: DeepPartial<GameState>): GameState {
+  const state = baseState();
+  if (!overrides) return state;
+  return deepMerge(state, overrides);
+}