convert events.TrailerReceived into a dataclass

Author: mhils

src/h2/events.py

@@ -13,7 +13,7 @@
 import binascii
 import sys
 from dataclasses import dataclass
-from typing import Any, TYPE_CHECKING
+from typing import TYPE_CHECKING, Any
 
 from .settings import ChangedSetting, SettingCodes, Settings, _setting_code_from_int
 
@@ -128,6 +128,7 @@ def __repr__(self) -> str:
         return f"<ResponseReceived stream_id:{self.stream_id}, headers:{self.headers}>"
 
 
+@dataclass(**kw_only)
 class TrailersReceived(Event):
     """
     The TrailersReceived event is fired whenever trailers are received on a
@@ -145,25 +146,28 @@ class TrailersReceived(Event):
        Added ``stream_ended`` and ``priority_updated`` properties.
     """
 
-    def __init__(self) -> None:
-        #: The Stream ID for the stream on which these trailers were received.
-        self.stream_id: int | None = None
+    stream_id: int
+    """The Stream ID for the stream on which these trailers were received."""
 
-        #: The trailers themselves.
-        self.headers: list[Header] | None = None
+    headers: list[Header] = _LAZY_INIT
+    """The trailers themselves."""
 
-        #: Trailers always end streams. This property has the associated
-        #: :class:`StreamEnded <h2.events.StreamEnded>` in it.
-        #:
-        #: .. versionadded:: 2.4.0
-        self.stream_ended: StreamEnded | None = None
+    stream_ended: StreamEnded | None = None
+    """
+    Trailers always end streams. This property has the associated
+    :class:`StreamEnded <h2.events.StreamEnded>` in it.
 
-        #: If the trailers also set associated priority information, the
-        #: associated :class:`PriorityUpdated <h2.events.PriorityUpdated>`
-        #: event will be available here.
-        #:
-        #: .. versionadded:: 2.4.0
-        self.priority_updated: PriorityUpdated | None = None
+    .. versionadded:: 2.4.0
+    """
+
+    priority_updated: PriorityUpdated | None = None
+    """
+    If the trailers also set associated priority information, the
+    associated :class:`PriorityUpdated <h2.events.PriorityUpdated>`
+    event will be available here.
+
+    .. versionadded:: 2.4.0
+    """
 
     def __repr__(self) -> str:
         return f"<TrailersReceived stream_id:{self.stream_id}, headers:{self.headers}>"

src/h2/stream.py

@@ -212,7 +212,7 @@ def response_received(self, previous_state: StreamState) -> list[Event]:
         else:
             assert not self.trailers_received
             self.trailers_received = True
-            event = TrailersReceived()
+            event = TrailersReceived(stream_id=self.stream_id)
 
         event.stream_id = self.stream_id
         return [event]

tests/test_events.py

@@ -144,9 +144,7 @@ def test_trailersreceived_repr(self) -> None:
         """
         TrailersReceived has a useful debug representation.
         """
-        e = h2.events.TrailersReceived()
-        e.stream_id = 62
-        e.headers = self.example_response_headers
+        e = h2.events.TrailersReceived(stream_id=62, headers=self.example_response_headers)
 
         assert repr(e) == (
             "<TrailersReceived stream_id:62, headers:["