feat: AI Town MVP - 完整三层架构实现

- Python FastAPI 引擎：世界状态模拟、全局能量条、世界事件系统
- Node.js WebSocket 服务器：实时通信、事件队列批处理
- 前端仪表盘：世界状态可视化、行动日志、事件展示

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

engine-python/tests/test_step.py

@@ -0,0 +1,173 @@
+import pytest
+from fastapi.testclient import TestClient
+import os
+import json
+from pathlib import Path
+
+from app.main import app
+from app.state import STATE_FILE, get_default_state, save_state
+
+
+@pytest.fixture(autouse=True)
+def reset_state():
+    """每个测试前重置状态文件"""
+    if STATE_FILE.exists():
+        STATE_FILE.unlink()
+    save_state(get_default_state())
+    yield
+    if STATE_FILE.exists():
+        STATE_FILE.unlink()
+
+
+@pytest.fixture
+def client():
+    return TestClient(app)
+
+
+def test_step_tick_increments(client):
+    """测试 tick 递增"""
+    # 第一次调用
+    resp1 = client.post("/step", json={"events": []})
+    assert resp1.status_code == 200
+    data1 = resp1.json()
+    assert data1["world_state"]["tick"] == 1
+
+    # 第二次调用
+    resp2 = client.post("/step", json={"events": []})
+    assert resp2.status_code == 200
+    data2 = resp2.json()
+    assert data2["world_state"]["tick"] == 2
+
+
+def test_mood_bounded(client):
+    """测试 town_mood 有界 (-10 到 10)"""
+    # 发送多个"支持"事件，测试上限
+    events = [
+        {"type": "comment", "text": "支持", "user": "test", "ts": i}
+        for i in range(15)
+    ]
+    resp = client.post("/step", json={"events": events})
+    data = resp.json()
+    assert data["world_state"]["town_mood"] <= 10
+
+    # 重置状态
+    save_state(get_default_state())
+
+    # 发送多个"混乱"事件，测试下限
+    events = [
+        {"type": "comment", "text": "混乱", "user": "test", "ts": i}
+        for i in range(15)
+    ]
+    resp = client.post("/step", json={"events": events})
+    data = resp.json()
+    assert data["world_state"]["town_mood"] >= -10
+
+
+def test_memory_max_length(client):
+    """测试 memory 长度不超过 3"""
+    events = [
+        {"type": "comment", "text": f"消息{i}", "user": "user1", "ts": i}
+        for i in range(10)
+    ]
+    resp = client.post("/step", json={"events": events})
+    data = resp.json()
+
+    for agent_id, agent in data["world_state"]["agents"].items():
+        assert len(agent["memory"]) <= 3
+
+
+def test_weather_change(client):
+    """测试天气变化"""
+    # 下雨
+    resp = client.post("/step", json={
+        "events": [{"type": "comment", "text": "下雨了", "user": "test", "ts": 1}]
+    })
+    assert resp.json()["world_state"]["weather"] == "rainy"
+
+    # 天晴
+    resp = client.post("/step", json={
+        "events": [{"type": "comment", "text": "天晴了", "user": "test", "ts": 2}]
+    })
+    assert resp.json()["world_state"]["weather"] == "sunny"
+
+
+def test_actions_generated(client):
+    """测试 actions 生成"""
+    resp = client.post("/step", json={"events": []})
+    data = resp.json()
+
+    assert len(data["actions"]) == 2
+    agent_ids = [a["agent_id"] for a in data["actions"]]
+    assert "alice" in agent_ids
+    assert "bob" in agent_ids
+
+    for action in data["actions"]:
+        assert "say" in action
+        assert "do" in action
+
+
+def test_global_meter_accumulates(client):
+    """测试能量累计"""
+    # comment 类型 +1
+    events = [{"type": "comment", "text": "hello", "user": "test", "ts": 1}]
+    resp = client.post("/step", json={"events": events})
+    data = resp.json()
+    assert data["world_state"]["global_meter"]["value"] == 1
+
+    # support 类型 +3
+    events = [{"type": "support", "text": "支持", "user": "test", "ts": 2}]
+    resp = client.post("/step", json={"events": events})
+    data = resp.json()
+    assert data["world_state"]["global_meter"]["value"] == 4
+
+    # chaos 类型 +5
+    events = [{"type": "chaos", "text": "混乱", "user": "test", "ts": 3}]
+    resp = client.post("/step", json={"events": events})
+    data = resp.json()
+    assert data["world_state"]["global_meter"]["value"] == 9
+
+
+def test_global_event_triggers(client):
+    """测试世界级事件触发"""
+    # 发送足够多的 chaos 事件达到阈值 (100)
+    # chaos +5, 需要 20 个事件
+    events = [
+        {"type": "chaos", "text": f"chaos{i}", "user": "test", "ts": i}
+        for i in range(20)
+    ]
+    resp = client.post("/step", json={"events": events})
+    data = resp.json()
+
+    # 验证事件触发
+    assert data["global_event"]["triggered"] is True
+    assert data["global_event"]["event"] is not None
+    assert "name" in data["global_event"]["event"]
+    assert "description" in data["global_event"]["event"]
+
+    # 验证能量重置和冷却设置
+    assert data["world_state"]["global_meter"]["value"] == 0
+    assert data["world_state"]["global_meter"]["cooldown"] == 5
+
+
+def test_global_event_cooldown(client):
+    """测试冷却期间不触发事件"""
+    # 先触发一次事件
+    events = [
+        {"type": "chaos", "text": f"chaos{i}", "user": "test", "ts": i}
+        for i in range(20)
+    ]
+    resp = client.post("/step", json={"events": events})
+    assert resp.json()["global_event"]["triggered"] is True
+
+    # 冷却期间再次达到阈值，不应触发
+    events = [
+        {"type": "chaos", "text": f"chaos{i}", "user": "test", "ts": i}
+        for i in range(20)
+    ]
+    resp = client.post("/step", json={"events": events})
+    data = resp.json()
+
+    # 不应触发（冷却中）
+    assert data["global_event"]["triggered"] is False
+    # 冷却递减
+    assert data["world_state"]["global_meter"]["cooldown"] == 4