integration tests pytest fixture for running local http server

python-packages/smithy-python/tests/integration/http_clients/conftest.py

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+# Copyright 2023 Amazon.com, Inc. or its affiliates. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License"). You
+# may not use this file except in compliance with the License. A copy of
+# the License is located at
+#
+#     http://aws.amazon.com/apache2.0/
+#
+# or in the "license" file accompanying this file. This file is
+# distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF
+# ANY KIND, either express or implied. See the License for the specific
+# language governing permissions and limitations under the License.
+import json
+from collections.abc import Generator
+from ctypes import c_int
+from http import HTTPStatus
+from http.server import BaseHTTPRequestHandler
+from multiprocessing import Event, Process, Value
+
+# multiprocessing.Event and multiprocessing.Value are wrapper functions for classes in
+# multiprocessing's submodules. As of Python 3.11, no type annotations are readily
+# available.
+from multiprocessing.synchronize import Event as MPEventClass
+from socketserver import TCPServer
+from threading import Thread
+
+import pytest
+
+
+class _IntegrationTestServerRequestHandler(BaseHTTPRequestHandler):
+    """HTTP server that echos the request's path and query string in JSON
+
+    Example response body:
+    {
+        "request_path": "/path?with=query",
+        "headers": {
+            "User-Agent": "Python-urllib/3.11",
+            "'Host": "localhost:60001"
+        },
+        "http_version": "HTTP/1.1"
+    }
+    """
+
+    protocol_version = "HTTP/1.1"
+
+    def do_GET(self) -> None:
+        content = {
+            "request_path": self.path,
+            "request_headers": {k: v for k, v in self.headers.items()},
+            "http_version": self.request_version,
+        }
+        content_json = json.dumps(content).encode("utf-8")
+        size = len(content_json)
+        self.send_response(HTTPStatus.OK)
+        self.send_header("Content-type", "application/json")
+        self.send_header("Content-Length", f"{size}")
+        self.end_headers()
+        self.wfile.write(content_json)
+
+
+def _run_integration_test_server(
+    server_ready_event: MPEventClass,
+    shutdown_event: MPEventClass,
+    # todo: find way to type this despite https://github.com/python/typeshed/issues/8799
+    port_number,
+) -> None:
+    with TCPServer(("localhost", 0), _IntegrationTestServerRequestHandler) as httpd:
+        server_thread = Thread(target=httpd.serve_forever)
+        server_thread.daemon = True
+        server_thread.start()
+        _, port = httpd.server_address
+        port_number.value = port
+        server_ready_event.set()
+        shutdown_event.wait()
+        httpd.shutdown()
+        server_thread.join()
+
+
+@pytest.fixture(scope="module")
+def running_server() -> Generator[int, None, None]:
+    """Runs a HTTP server that responds to GET requests with a JSON response
+
+    The fixture value is the port number of the HTTP server on localhost.
+    """
+    server_ready_event = Event()
+    shutdown_event = Event()
+    port_number = Value(c_int)
+    proc = Process(
+        target=_run_integration_test_server,
+        kwargs={
+            "server_ready_event": server_ready_event,
+            "shutdown_event": shutdown_event,
+            "port_number": port_number,
+        },
+    )
+    proc.start()
+    # wait up to one second for http server to start
+    server_ready_event.wait(timeout=1.0)
+    yield int(port_number.value)
+    shutdown_event.set()
+    # wait for server process to terminate
+    proc.join()

python-packages/smithy-python/tests/integration/http_clients/test_http_basics.py

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+# Copyright 2023 Amazon.com, Inc. or its affiliates. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License"). You
+# may not use this file except in compliance with the License. A copy of
+# the License is located at
+#
+#     http://aws.amazon.com/apache2.0/
+#
+# or in the "license" file accompanying this file. This file is
+# distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF
+# ANY KIND, either express or implied. See the License for the specific
+# language governing permissions and limitations under the License.
+
+import json
+import urllib.request
+
+# mypy: allow-untyped-defs
+# mypy: allow-incomplete-defs
+
+
+def test_uses_local_integ_test_server(running_server) -> None:
+    port = running_server
+    url = f"http://localhost:{port}"
+    with urllib.request.urlopen(url) as f:
+        resp = f.read().decode("utf-8")
+    resp_json = json.loads(resp)
+    assert resp_json["request_headers"]["User-Agent"] == "Python-urllib/3.11"