Support for setting the live server port (pytest-dev#500)

* Allow setting the live server port for Django >= 1.11.2.
* Removed warning when specifying live server port with Django >= 1.11 < 1.11.2.
* Added test for specifying a live server port with Django >= 1.11.2.

pytest_django/fixtures.py

@@ -302,10 +302,14 @@ def live_server(request):
     addr = (request.config.getvalue('liveserver') or
             os.getenv('DJANGO_LIVE_TEST_SERVER_ADDRESS'))
 
-    if addr and django.VERSION >= (1, 11) and ':' in addr:
-        request.config.warn('D001', 'Specifying a live server port is not supported '
-                            'in Django 1.11. This will be an error in a future '
-                            'pytest-django release.')
+    if addr and ':' in addr:
+        if django.VERSION >= (1, 11):
+            ports = addr.split(':')[1]
+            if '-' in ports or ',' in ports:
+                request.config.warn('D001',
+                                    'Specifying multiple live server ports is not supported '
+                                    'in Django 1.11. This will be an error in a future '
+                                    'pytest-django release.')
 
     if not addr:
         if django.VERSION < (1, 11):

pytest_django/live_server_helper.py

@@ -38,7 +38,12 @@ def __init__(self, addr):
             self.thread = LiveServerThread(host, possible_ports,
                                            **liveserver_kwargs)
         else:
-            host = addr
+            try:
+                host, port = addr.split(':')
+            except ValueError:
+                host = addr
+            else:
+                liveserver_kwargs['port'] = int(port)
             self.thread = LiveServerThread(host, **liveserver_kwargs)
 
         self._live_server_modified_settings = modify_settings(

tests/test_fixtures.py

@@ -6,6 +6,8 @@
 
 from __future__ import with_statement
 
+import socket
+
 import pytest
 
 from django.db import connection, transaction
@@ -321,18 +323,35 @@ def test_serve_static_dj17_without_staticfiles_app(self, live_server,
 
     @pytest.mark.skipif(get_django_version() < (1, 11),
                         reason='Django >= 1.11 required')
-    def test_specified_port_error_message_django_111(self, django_testdir):
+    def test_specified_port_range_error_message_django_111(self, django_testdir):
         django_testdir.create_test_module("""
         def test_with_live_server(live_server):
             pass
         """)
 
-        result = django_testdir.runpytest_subprocess('--liveserver=localhost:1234')
+        result = django_testdir.runpytest_subprocess('--liveserver=localhost:1234-2345')
         result.stdout.fnmatch_lines([
-            '*Specifying a live server port is not supported in Django 1.11. This '
+            '*Specifying multiple live server ports is not supported in Django 1.11. This '
             'will be an error in a future pytest-django release.*'
         ])
 
+    @pytest.mark.skipif(get_django_version() < (1, 11, 2),
+                        reason='Django >= 1.11.2 required')
+    def test_specified_port_django_111(self, django_testdir):
+        sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+        try:
+            sock.bind(('', 0))
+            __, port = sock.getsockname()
+        finally:
+            sock.close()
+
+        django_testdir.create_test_module("""
+        def test_with_live_server(live_server):
+            assert live_server.port == %d
+        """ % port)
+
+        django_testdir.runpytest_subprocess('--liveserver=localhost:%s' % port)
+
 
 @pytest.mark.django_project(extra_settings="""
     AUTH_USER_MODEL = 'app.MyCustomUser'