Implement the --django-debug plugin option with tests

Author: dulacp

docs/changelog.rst

@@ -1,5 +1,12 @@
 Changelog
-=========
+
+Unreleased
+----------
+
+Bugfixes
+^^^^^^^^
+
+* Added a new option `--django-debug` to specify the default DEBUG setting (#228)
 
 3.4.8 (2019-02-26)
 ------------------

docs/configuring_django.rst

@@ -104,3 +104,17 @@ itself::
         project.app.signals.something = noop
 
 This plugin can then be used e.g. via ``-p`` in :pytest-confval:`addopts`.
+
+``DEBUG`` setting during the test run
+-------------------------------------
+
+By default, django test runner behavior is to force DEBUG setting to False. So does the ``pytest-django``.
+But sometimes, especially for functional tests, you might want to avoid this, to debug why certain page does not work.
+
+Command Line Option::
+
+    $ py.test --django-debug True|False|None
+
+``None`` ensure there is no override of the test settings DEBUG value
+``True`` override DEBUG to True
+``False`` override DEBUG to False

pytest_django/plugin.py

@@ -5,6 +5,7 @@
 """
 
 import contextlib
+from distutils.util import strtobool
 import inspect
 from functools import reduce
 import os
@@ -106,6 +107,13 @@ def pytest_addoption(parser):
         default=False,
         help="Enable Django migrations on test setup",
     )
+    group._addoption(
+        "--django-debug",
+        action="store",
+        dest="djangodebug",
+        default="None",
+        help="Configure the DEBUG setting. Defaults to False"
+    )
     parser.addini(
         CONFIGURATION_ENV, "django-configurations class to use by pytest-django."
     )
@@ -466,7 +474,9 @@ def django_test_environment(request):
         from django.conf import settings as dj_settings
         from django.test.utils import setup_test_environment, teardown_test_environment
 
-        dj_settings.DEBUG = False
+        if request.config.getvalue('djangodebug') != 'None':
+            dj_settings.DEBUG = bool(strtobool(request.config.getvalue('djangodebug')))
+
         setup_test_environment()
         request.addfinalizer(teardown_test_environment)
 

tests/test_django_settings_module.py

@@ -308,6 +308,81 @@ def test_debug_is_false():
     assert r.ret == 0
 
 
+def test_no_debug_override(testdir, monkeypatch):
+    monkeypatch.delenv('DJANGO_SETTINGS_MODULE')
+    testdir.makeconftest("""
+        from django.conf import settings
+
+        def pytest_configure():
+            settings.configure(SECRET_KEY='set from pytest_configure',
+                               DEBUG=True,
+                               DATABASES={'default': {
+                                   'ENGINE': 'django.db.backends.sqlite3',
+                                   'NAME': ':memory:'}},
+                               INSTALLED_APPS=['django.contrib.auth',
+                                               'django.contrib.contenttypes',])
+    """)
+
+    testdir.makepyfile("""
+        from django.conf import settings
+        def test_debug_is_unchanged():
+            assert settings.DEBUG is True
+    """)
+
+    r = testdir.runpytest_subprocess('--django-debug=None')
+    assert r.ret == 0
+
+
+def test_override_debug_to_false(testdir, monkeypatch):
+    monkeypatch.delenv('DJANGO_SETTINGS_MODULE')
+    testdir.makeconftest("""
+        from django.conf import settings
+
+        def pytest_configure():
+            settings.configure(SECRET_KEY='set from pytest_configure',
+                               DEBUG=True,
+                               DATABASES={'default': {
+                                   'ENGINE': 'django.db.backends.sqlite3',
+                                   'NAME': ':memory:'}},
+                               INSTALLED_APPS=['django.contrib.auth',
+                                               'django.contrib.contenttypes',])
+    """)
+
+    testdir.makepyfile("""
+        from django.conf import settings
+        def test_debug_is_false():
+            assert settings.DEBUG is False
+    """)
+
+    r = testdir.runpytest_subprocess('--django-debug=False')
+    assert r.ret == 0
+
+
+def test_override_debug_to_true(testdir, monkeypatch):
+    monkeypatch.delenv('DJANGO_SETTINGS_MODULE')
+    testdir.makeconftest("""
+        from django.conf import settings
+
+        def pytest_configure():
+            settings.configure(SECRET_KEY='set from pytest_configure',
+                               DEBUG=True,
+                               DATABASES={'default': {
+                                   'ENGINE': 'django.db.backends.sqlite3',
+                                   'NAME': ':memory:'}},
+                               INSTALLED_APPS=['django.contrib.auth',
+                                               'django.contrib.contenttypes',])
+    """)
+
+    testdir.makepyfile("""
+        from django.conf import settings
+        def test_debug_is_true():
+            assert settings.DEBUG is True
+    """)
+
+    r = testdir.runpytest_subprocess('--django-debug=True')
+    assert r.ret == 0
+
+
 @pytest.mark.skipif(
     not hasattr(django, "setup"),
     reason="This Django version does not support app loading",