fix crash when importing pluggy.Result on old versions of pluggy (microsoft#23866)

fixes microsoft#23816

---------

Co-authored-by: detachhead <detachhead@users.noreply.github.com>
Co-authored-by: eleanorjboyd <eleanorboyd@microsoft.com>

Author: DetachHead

python_files/vscode_pytest/__init__.py

@@ -1,31 +1,33 @@
 # Copyright (c) Microsoft Corporation. All rights reserved.
 # Licensed under the MIT License.
 
+from __future__ import annotations
+
 import atexit
 import json
 import os
 import pathlib
 import sys
 import traceback
 from typing import (
+    TYPE_CHECKING,
     Any,
     Dict,
     Generator,
-    List,
     Literal,
-    Optional,
     TypedDict,
-    Union,
 )
 
 import pytest
-from pluggy import Result
 
 script_dir = pathlib.Path(__file__).parent.parent
 sys.path.append(os.fspath(script_dir))
 sys.path.append(os.fspath(script_dir / "lib" / "python"))
 from testing_tools import socket_manager  # noqa: E402
 
+if TYPE_CHECKING:
+    from pluggy import Result
+
 
 class TestData(TypedDict):
     """A general class that all test objects inherit from."""
@@ -46,7 +48,7 @@ class TestItem(TestData):
 class TestNode(TestData):
     """A general class that handles all test data which contains children."""
 
-    children: "list[Union[TestNode, TestItem, None]]"
+    children: list[TestNode | TestItem | None]
 
 
 class VSCodePytestError(Exception):
@@ -209,17 +211,17 @@ class TestOutcome(Dict):
 
     test: str
     outcome: Literal["success", "failure", "skipped", "error"]
-    message: Union[str, None]
-    traceback: Union[str, None]
-    subtest: Optional[str]
+    message: str | None
+    traceback: str | None
+    subtest: str | None
 
 
 def create_test_outcome(
     testid: str,
     outcome: str,
-    message: Union[str, None],
-    traceback: Union[str, None],
-    subtype: Optional[str] = None,  # noqa: ARG001
+    message: str | None,
+    traceback: str | None,
+    subtype: str | None = None,  # noqa: ARG001
 ) -> TestOutcome:
     """A function that creates a TestOutcome object."""
     return TestOutcome(
@@ -235,7 +237,7 @@ class TestRunResultDict(Dict[str, Dict[str, TestOutcome]]):
     """A class that stores all test run results."""
 
     outcome: str
-    tests: Dict[str, TestOutcome]
+    tests: dict[str, TestOutcome]
 
 
 @pytest.hookimpl(hookwrapper=True, trylast=True)
@@ -384,7 +386,7 @@ def pytest_sessionfinish(session, exitstatus):
             }
             post_response(os.fsdecode(cwd), error_node)
         try:
-            session_node: Union[TestNode, None] = build_test_tree(session)
+            session_node: TestNode | None = build_test_tree(session)
             if not session_node:
                 raise VSCodePytestError(
                     "Something went wrong following pytest finish, \
@@ -430,10 +432,10 @@ def build_test_tree(session: pytest.Session) -> TestNode:
     session -- the pytest session object.
     """
     session_node = create_session_node(session)
-    session_children_dict: Dict[str, TestNode] = {}
-    file_nodes_dict: Dict[Any, TestNode] = {}
-    class_nodes_dict: Dict[str, TestNode] = {}
-    function_nodes_dict: Dict[str, TestNode] = {}
+    session_children_dict: dict[str, TestNode] = {}
+    file_nodes_dict: dict[Any, TestNode] = {}
+    class_nodes_dict: dict[str, TestNode] = {}
+    function_nodes_dict: dict[str, TestNode] = {}
 
     # Check to see if the global variable for symlink path is set
     if SYMLINK_PATH:
@@ -492,7 +494,7 @@ def build_test_tree(session: pytest.Session) -> TestNode:
         if isinstance(test_case.parent, pytest.Class):
             case_iter = test_case.parent
             node_child_iter = test_node
-            test_class_node: Union[TestNode, None] = None
+            test_class_node: TestNode | None = None
             while isinstance(case_iter, pytest.Class):
                 # While the given node is a class, create a class and nest the previous node as a child.
                 try:
@@ -529,7 +531,7 @@ def build_test_tree(session: pytest.Session) -> TestNode:
                 parent_test_case = create_file_node(test_case.parent)
                 file_nodes_dict[test_case.parent] = parent_test_case
             parent_test_case["children"].append(test_node)
-    created_files_folders_dict: Dict[str, TestNode] = {}
+    created_files_folders_dict: dict[str, TestNode] = {}
     for file_node in file_nodes_dict.values():
         # Iterate through all the files that exist and construct them into nested folders.
         root_folder_node: TestNode
@@ -562,7 +564,7 @@ def build_test_tree(session: pytest.Session) -> TestNode:
 
 def build_nested_folders(
     file_node: TestNode,
-    created_files_folders_dict: Dict[str, TestNode],
+    created_files_folders_dict: dict[str, TestNode],
     session_node: TestNode,
 ) -> TestNode:
     """Takes a file or folder and builds the nested folder structure for it.
@@ -722,18 +724,18 @@ class DiscoveryPayloadDict(TypedDict):
 
     cwd: str
     status: Literal["success", "error"]
-    tests: Optional[TestNode]
-    error: Optional[List[str]]
+    tests: TestNode | None
+    error: list[str] | None
 
 
 class ExecutionPayloadDict(Dict):
     """A dictionary that is used to send a execution post request to the server."""
 
     cwd: str
     status: Literal["success", "error"]
-    result: Union[TestRunResultDict, None]
-    not_found: Union[List[str], None]  # Currently unused need to check
-    error: Union[str, None]  # Currently unused need to check
+    result: TestRunResultDict | None
+    not_found: list[str] | None  # Currently unused need to check
+    error: str | None  # Currently unused need to check
 
 
 class EOTPayloadDict(TypedDict):
@@ -782,9 +784,7 @@ def get_node_path(node: Any) -> pathlib.Path:
 atexit.register(lambda: __writer.close() if __writer else None)
 
 
-def execution_post(
-    cwd: str, status: Literal["success", "error"], tests: Union[TestRunResultDict, None]
-):
+def execution_post(cwd: str, status: Literal["success", "error"], tests: TestRunResultDict | None):
     """Sends a POST request with execution payload details.
 
     Args:
@@ -829,7 +829,7 @@ def default(self, obj):
 
 
 def send_post_request(
-    payload: Union[ExecutionPayloadDict, DiscoveryPayloadDict, EOTPayloadDict],
+    payload: ExecutionPayloadDict | DiscoveryPayloadDict | EOTPayloadDict,
     cls_encoder=None,
 ):
     """