Add --live-server-port option

Author: RazerM

docs/features.rst

@@ -174,6 +174,17 @@ example, in your project’s ``pytest.ini`` file)::
             assert b'got it' in res.read()
 
 
+``--live-server-port`` - use a fixed port
+`````````````````````````````````````````
+
+By default the server uses a random port. In some cases it is desirable to run
+the server with a fixed port. You can use ``--live-server-port`` (for example,
+in your project's ``pytest.ini`` file)::
+
+    [pytest]
+    addopts = --live-server-port=5000
+
+
 ``request_ctx`` - request context
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 

pytest_flask/fixtures.py

@@ -98,7 +98,7 @@ def _rewrite_server_name(server_name, new_port):
 
 
 @pytest.fixture(scope='function')
-def live_server(request, app, monkeypatch):
+def live_server(request, app, monkeypatch, pytestconfig):
     """Run application in a separate process.
 
     When the ``live_server`` fixture is applied, the ``url_for`` function
@@ -112,11 +112,14 @@ def test_server_is_up_and_running(live_server):
             assert res.code == 200
 
     """
-    # Bind to an open port
-    s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
-    s.bind(('', 0))
-    port = s.getsockname()[1]
-    s.close()
+    port = pytestconfig.getvalue('live_server_port')
+
+    if port == 0:
+        # Bind to an open port
+        s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+        s.bind(('', 0))
+        port = s.getsockname()[1]
+        s.close()
 
     # Explicitly set application ``SERVER_NAME`` for test suite
     # and restore original value on test teardown.

pytest_flask/plugin.py

@@ -124,6 +124,8 @@ def pytest_addoption(parser):
                     action="store_false", dest="start_live_server",
                     help="don't start server automatically when live_server "
                          "fixture is applied.")
+    group.addoption('--live-server-port', action='store', default=0, type=int,
+                    help='use a fixed port for the live_server fixture.')
 
 
 def pytest_configure(config):

tests/test_live_server.py

@@ -116,3 +116,15 @@ def two():
         result = appdir.runpytest('-v', '--no-start-live-server')
         result.stdout.fnmatch_lines(['*PASSED*'])
         assert result.ret == 0
+
+    @pytest.mark.parametrize('port', [5000, 5001])
+    def test_live_server_fixed_port(self, port, appdir):
+        appdir.create_test_module('''
+            import pytest
+
+            def test_port(live_server):
+                assert live_server.port == %d
+        ''' % port)
+        result = appdir.runpytest('-v', '--live-server-port', port)
+        result.stdout.fnmatch_lines(['*PASSED*'])
+        assert result.ret == 0