Let SanicTestClient has its own port

For parallel test running, the servers must have different ports.
See examples/pytest_xdist.py for example.

examples/pytest_xdist.py

@@ -0,0 +1,49 @@
+"""pytest-xdist example for sanic server
+
+Install testing tools:
+
+    $ pip install pytest pytest-xdist
+
+Run with xdist params:
+
+    $ pytest examples/pytest_xdist.py -n 8  # 8 workers
+"""
+import re
+from sanic import Sanic
+from sanic.response import text
+from sanic.testing import PORT as PORT_BASE, SanicTestClient
+import pytest
+
+
+@pytest.fixture(scope="session")
+def test_port(worker_id):
+    m = re.search(r'[0-9]+', worker_id)
+    if m:
+        num_id = m.group(0)
+    else:
+        num_id = 0
+    port = PORT_BASE + int(num_id)
+    return port
+
+
+@pytest.fixture(scope="session")
+def app():
+    app = Sanic()
+
+    @app.route('/')
+    async def index(request):
+        return text('OK')
+
+    return app
+
+
+@pytest.fixture(scope="session")
+def client(app, test_port):
+    return SanicTestClient(app, test_port)
+
+
+@pytest.mark.parametrize('run_id', range(100))
+def test_index(client, run_id):
+    request, response = client._sanic_endpoint_test('get', '/')
+    assert response.status == 200
+    assert response.text == 'OK'

sanic/testing.py

@@ -8,8 +8,9 @@ PORT = 42101
 
 
 class SanicTestClient:
-    def __init__(self, app):
+    def __init__(self, app, port=PORT):
         self.app = app
+        self.port = port
 
     async def _local_request(self, method, uri, cookies=None, *args, **kwargs):
         import aiohttp
@@ -17,7 +18,7 @@ class SanicTestClient:
             url = uri
         else:
             url = 'http://{host}:{port}{uri}'.format(
-                host=HOST, port=PORT, uri=uri)
+                host=HOST, port=self.port, uri=uri)
 
         logger.info(url)
         conn = aiohttp.TCPConnector(verify_ssl=False)
@@ -66,7 +67,7 @@ class SanicTestClient:
                 exceptions.append(e)
             self.app.stop()
 
-        self.app.run(host=HOST, debug=debug, port=PORT, **server_kwargs)
+        self.app.run(host=HOST, debug=debug, port=self.port, **server_kwargs)
         self.app.listeners['after_server_start'].pop()
 
         if exceptions: