refactor: 全面迁移至 Python 3.9+ 原生泛型类型语法

- 将所有 `Optional[T]` 替换为 `T | None`
- 将所有 `List[T]`/`Dict[K, V]`/`Tuple[Ts, ...]` 替换为对应原生泛型
- 调整类型导入，移除冗余的 typing 导入项
- 更新项目依赖，添加 typing-extensions 兼容旧版本 Python
- 重构部分函数签名与内部实现以匹配新类型语法

tests/test_executors_edge_cases.py

@@ -0,0 +1,189 @@
+"""Tests for executors module edge cases."""
+
+import asyncio
+import sys
+
+import pytest
+
+import pyflowx as px
+from pyflowx.task import TaskStatus
+
+# 跨平台的 echo 命令
+if sys.platform == "win32":
+    ECHO_CMD = ["cmd", "/c", "echo"]
+else:
+    ECHO_CMD = ["echo"]
+
+
+def test_execute_sync_with_timeout():
+    """Test execute task with timeout correctly."""
+    # Note: timeout for Python functions only works in async strategy
+    # For sync functions, timeout is not enforced in sequential strategy
+    # This test verifies that the task runs without timeout error
+    spec = px.TaskSpec("quick", fn=lambda: "result", timeout=10)
+    graph = px.Graph.from_specs([spec])
+
+    # Should succeed without timeout error
+    report = px.run(graph, strategy="sequential")
+    assert report.success
+
+
+def test_execute_async_with_timeout():
+    """Test execute async task with timeout correctly."""
+
+    async def slow_async_function():
+        await asyncio.sleep(2)
+        return "result"
+
+    spec = px.TaskSpec("slow_async", fn=slow_async_function, timeout=0.5)
+    graph = px.Graph.from_specs([spec])
+
+    # This should timeout
+    with pytest.raises(px.TaskFailedError):
+        px.run(graph, strategy="async")
+
+
+def test_verbose_event_callback_running():
+    """Test verbose event callback for RUNNING status."""
+    # Create a graph with verbose callback
+    spec = px.TaskSpec("test", fn=lambda: "result", verbose=True)
+    graph = px.Graph.from_specs([spec])
+    report = px.run(graph, strategy="sequential")
+    # Should print without error
+    assert report.success
+
+
+def test_verbose_event_callback_success():
+    """Test verbose event callback for SUCCESS status."""
+    # Create a graph with verbose callback
+    spec = px.TaskSpec("test", fn=lambda: "result", verbose=True)
+    graph = px.Graph.from_specs([spec])
+    report = px.run(graph, strategy="sequential")
+    # Should print without error
+    assert report.success
+
+
+def test_verbose_event_callback_failed():
+    """Test verbose event callback for FAILED status."""
+    # Create a graph with verbose callback and failing task
+
+    def raise_error():
+        raise ValueError("test error")
+
+    spec = px.TaskSpec("test", fn=raise_error, verbose=True)
+    graph = px.Graph.from_specs([spec])
+
+    # Should print without error
+    with pytest.raises(px.TaskFailedError):
+        px.run(graph, strategy="sequential")
+
+
+def test_verbose_event_callback_skipped():
+    """Test verbose event callback for SKIPPED status."""
+    # Create a graph with verbose callback and skipped task
+    spec = px.TaskSpec(
+        "test",
+        fn=lambda: "result",
+        conditions=(lambda: False,),
+        verbose=True,
+    )
+    graph = px.Graph.from_specs([spec])
+    report = px.run(graph, strategy="sequential")
+    # Should print without error
+    assert report.success
+
+
+def test_execute_sync_with_retries():
+    """Test execute task with retries."""
+
+    call_count = 0
+
+    def failing_function():
+        nonlocal call_count
+        call_count += 1
+        if call_count < 3:
+            raise ValueError("temporary error")
+        return "success"
+
+    spec = px.TaskSpec("retry_test", fn=failing_function, retries=3)
+    graph = px.Graph.from_specs([spec])
+
+    # Should succeed after retries
+    report = px.run(graph, strategy="sequential")
+    assert report.success
+    assert report.results["retry_test"].attempts == 3
+
+
+def test_execute_async_with_retries():
+    """Test execute async task with retries."""
+
+    call_count = 0
+
+    async def failing_async_function():
+        nonlocal call_count
+        call_count += 1
+        if call_count < 3:
+            raise ValueError("temporary error")
+        return "success"
+
+    spec = px.TaskSpec("retry_async_test", fn=failing_async_function, retries=3)
+    graph = px.Graph.from_specs([spec])
+
+    # Should succeed after retries
+    report = px.run(graph, strategy="async")
+    assert report.success
+    assert report.results["retry_async_test"].attempts == 3
+
+
+def test_execute_sync_skip_on_condition():
+    """Test execute task skips task when condition is false."""
+    spec = px.TaskSpec(
+        "skip_test",
+        fn=lambda: "result",
+        conditions=(lambda: False,),
+    )
+    graph = px.Graph.from_specs([spec])
+
+    report = px.run(graph, strategy="sequential")
+    assert report.success
+    assert report.results["skip_test"].status == TaskStatus.SKIPPED
+
+
+def test_execute_async_skip_on_condition():
+    """Test execute async task skips task when condition is false."""
+    spec = px.TaskSpec(
+        "skip_async_test",
+        fn=lambda: "result",
+        conditions=(lambda: False,),
+    )
+    graph = px.Graph.from_specs([spec])
+
+    report = px.run(graph, strategy="async")
+    assert report.success
+    assert report.results["skip_async_test"].status == TaskStatus.SKIPPED
+
+
+def test_execute_sync_with_error():
+    """Test execute task handles errors correctly."""
+
+    def error_function():
+        raise ValueError("test error")
+
+    spec = px.TaskSpec("error_test", fn=error_function)
+    graph = px.Graph.from_specs([spec])
+
+    with pytest.raises(px.TaskFailedError):
+        px.run(graph, strategy="sequential")
+
+
+def test_execute_async_with_error():
+    """Test execute async task handles errors correctly."""
+
+    async def error_async_function():
+        raise ValueError("test error")
+
+    spec = px.TaskSpec("error_async_test", fn=error_async_function)
+    graph = px.Graph.from_specs([spec])
+
+    with pytest.raises(px.TaskFailedError):
+        px.run(graph, strategy="async")