webhooks: Migrate travis to use @typed_endpoint.

To perform the same check, we define a Pydantic model. This includes
some keys "build_url" and "type" that we did not check for previously.

zerver/webhooks/travis/view.py

@@ -1,12 +1,12 @@
 # Webhooks for external integrations.
-from typing import Dict
 
 from django.http import HttpRequest, HttpResponse
+from pydantic import BaseModel, Json
+from typing_extensions import Annotated
 
 from zerver.decorator import webhook_view
-from zerver.lib.request import REQ, has_request_variables
 from zerver.lib.response import json_success
-from zerver.lib.validator import check_bool, check_dict, check_string
+from zerver.lib.typed_endpoint import ApiParamConfig, typed_endpoint
 from zerver.lib.webhooks.common import check_send_webhook_message
 from zerver.models import UserProfile
 
@@ -24,26 +24,26 @@ Build status: {} {}
 Details: [changes]({}), [build log]({})"""
 
 
+class TravisPayload(BaseModel):
+    author_name: str
+    status_message: str
+    compare_url: str
+    build_url: str
+    type: str
+
+
 @webhook_view("Travis", all_event_types=ALL_EVENT_TYPES)
-@has_request_variables
+@typed_endpoint
 def api_travis_webhook(
     request: HttpRequest,
     user_profile: UserProfile,
-    ignore_pull_requests: bool = REQ(json_validator=check_bool, default=True),
-    message: Dict[str, object] = REQ(
-        "payload",
-        json_validator=check_dict(
-            [
-                ("author_name", check_string),
-                ("status_message", check_string),
-                ("compare_url", check_string),
-            ]
-        ),
-    ),
+    *,
+    message: Annotated[Json[TravisPayload], ApiParamConfig("payload")],
+    ignore_pull_requests: Json[bool] = True,
 ) -> HttpResponse:
-    event = str(message["type"])
-    message_status = message["status_message"]
-    if ignore_pull_requests and message["type"] == "pull_request":
+    event = message.type
+    message_status = message.status_message
+    if ignore_pull_requests and message.type == "pull_request":
         return json_success(request)
 
     if message_status in GOOD_STATUSES:
@@ -56,11 +56,11 @@ def api_travis_webhook(
         emoji = f"(No emoji specified for status '{message_status}'.)"
 
     body = MESSAGE_TEMPLATE.format(
-        message["author_name"],
+        message.author_name,
         message_status,
         emoji,
-        message["compare_url"],
-        message["build_url"],
+        message.compare_url,
+        message.build_url,
     )
     topic = "builds"