refactor: 推进后端分层架构治理

tests/test_event_runtime_components.py

@@ -0,0 +1,128 @@
+"""事件注册、绑定、调度和错误策略组件的独立测试。"""
+
+import threading
+from unittest.mock import Mock
+
+from app.runtime.event.binding import (
+    EventBindingResolver,
+    EventHandlerBinding,
+)
+from app.runtime.event.errors import EventErrorPolicy
+from app.runtime.events import Event
+from app.schemas.types import EventType
+from app.startup.modules_initializer import get_host_event_handler_factories
+
+
+class _UnmanagedHandler:
+    """记录构造次数，用于证明绑定未命中时不会被总线实例化。"""
+
+    constructed = 0
+
+    def __init__(self) -> None:
+        """记录任何非预期的隐式构造。"""
+        type(self).constructed += 1
+
+    def handle(self, _event: Event) -> None:
+        """提供可解析的实例方法声明。"""
+
+
+def test_binding_miss_does_not_construct_handler_owner() -> None:
+    """resolver 未命中时只记录诊断，不能调用 owner_class()。"""
+    resolvers = {}
+    binding = EventBindingResolver(
+        lock=threading.Lock(),
+        resolvers=lambda: resolvers,
+    )
+    _UnmanagedHandler.constructed = 0
+
+    assert binding.resolve(_UnmanagedHandler.handle) is None
+    assert _UnmanagedHandler.constructed == 0
+    assert binding.unresolved_handlers() == (
+        f"{__name__}._UnmanagedHandler.handle",
+    )
+
+
+def test_binding_uses_explicit_resolver_instance() -> None:
+    """显式 resolver 应返回当前托管实例上的绑定方法。"""
+    instance = object.__new__(_UnmanagedHandler)
+    resolvers = {
+        "test": lambda owner: EventHandlerBinding(
+            instance=instance,
+            owner_name="托管处理器",
+        )
+        if owner is _UnmanagedHandler
+        else None
+    }
+    binding = EventBindingResolver(
+        lock=threading.Lock(),
+        resolvers=lambda: resolvers,
+    )
+
+    method, resolved, class_name, method_name = binding.resolve(
+        _UnmanagedHandler.handle
+    )
+
+    assert method.__self__ is instance
+    assert resolved.owner_name == "托管处理器"
+    assert class_name == "_UnmanagedHandler"
+    assert method_name == "handle"
+
+
+def test_system_error_failure_does_not_rebroadcast() -> None:
+    """SystemError 处理器自身失败时只能通知和日志降级，不能再次发送事件。"""
+    notifier = Mock()
+    emit = Mock()
+    policy = EventErrorPolicy(
+        notifier=lambda: notifier,
+        emit_system_error=emit,
+    )
+
+    policy.handle(
+        event=Event(EventType.SystemError, {}),
+        module_name="测试模块",
+        class_name="BrokenHandler",
+        method_name="handle",
+        error=RuntimeError("broken"),
+    )
+
+    notifier.assert_called_once()
+    emit.assert_not_called()
+
+
+def test_regular_event_failure_emits_one_system_error() -> None:
+    """普通事件失败应生成一次结构稳定的 SystemError 载荷。"""
+    emit = Mock()
+    policy = EventErrorPolicy(
+        notifier=lambda: None,
+        emit_system_error=emit,
+    )
+
+    policy.handle(
+        event=Event(EventType.ConfigChanged, {}),
+        module_name="测试模块",
+        class_name="BrokenHandler",
+        method_name="handle",
+        error=RuntimeError("broken"),
+    )
+
+    payload = emit.call_args.args[0]
+    assert payload["type"] == "event"
+    assert payload["event_type"] is EventType.ConfigChanged
+    assert payload["event_handle"] == "BrokenHandler.handle"
+    assert payload["error"] == "broken"
+
+
+def test_all_decorated_host_handler_classes_have_explicit_factories() -> None:
+    """宿主中使用事件装饰器的类必须全部由组合根 resolver 白名单接管。"""
+    factories = get_host_event_handler_factories()
+
+    assert {owner.__name__ for owner in factories} == {
+        "Command",
+        "DownloadChain",
+        "Scheduler",
+        "ScrapingChain",
+        "SearchChain",
+        "SiteChain",
+        "SubscribeChain",
+        "WorkflowChain",
+    }