Run the tests by default with postgresql

Most real-world instances will use postgresql instead of sqlite so it's
better to use postgres for the tests. This also allows us to easily add
tests for concurrency issues which is not supported by sqlite

tests/_site/myauth/migrations/0001_initial.py

@@ -0,0 +1,39 @@
+# -*- coding: utf-8 -*-
+# Generated by Django 1.10.6 on 2017-03-30 14:35
+from __future__ import unicode_literals
+
+import django.core.validators
+from django.db import migrations, models
+import django.utils.timezone
+import re
+
+
+class Migration(migrations.Migration):
+
+    initial = True
+
+    dependencies = [
+        ('auth', '0008_alter_user_username_max_length'),
+    ]
+
+    operations = [
+        migrations.CreateModel(
+            name='User',
+            fields=[
+                ('id', models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('password', models.CharField(max_length=128, verbose_name='password')),
+                ('last_login', models.DateTimeField(blank=True, null=True, verbose_name='last login')),
+                ('is_superuser', models.BooleanField(default=False, help_text='Designates that this user has all permissions without explicitly assigning them.', verbose_name='superuser status')),
+                ('email', models.EmailField(max_length=254, unique=True, verbose_name='email address')),
+                ('first_name', models.CharField(blank=True, max_length=255, verbose_name='First name')),
+                ('last_name', models.CharField(blank=True, max_length=255, verbose_name='Last name')),
+                ('is_staff', models.BooleanField(default=False, help_text='Designates whether the user can log into this admin site.', verbose_name='Staff status')),
+                ('is_active', models.BooleanField(default=True, help_text='Designates whether this user should be treated as active. Unselect this instead of deleting accounts.', verbose_name='Active')),
+                ('date_joined', models.DateTimeField(default=django.utils.timezone.now, verbose_name='date joined')),
+                ('username', models.CharField(help_text='Required. 30 characters or fewer. Letters, numbers and @/./+/-/_ characters', max_length=30, unique=True, validators=[django.core.validators.RegexValidator(re.compile('^[\\w.@+-]+$', 32), 'Enter a valid username.', 'invalid')], verbose_name='username')),
+                ('extra_field', models.CharField(blank=True, max_length=5, verbose_name='Nobody needs me')),
+                ('groups', models.ManyToManyField(blank=True, help_text='The groups this user belongs to. A user will get all permissions granted to each of their groups.', related_name='user_set', related_query_name='user', to='auth.Group', verbose_name='groups')),
+                ('user_permissions', models.ManyToManyField(blank=True, help_text='Specific permissions for this user.', related_name='user_set', related_query_name='user', to='auth.Permission', verbose_name='user permissions')),
+            ],
+        ),
+    ]

tests/conftest.py

@@ -5,7 +5,7 @@
 
 
 def pytest_addoption(parser):
-    parser.addoption('--postgres', action='store_true')
+    parser.addoption('--sqlite', action='store_true')
     parser.addoption(
         '--deprecation', choices=['strict', 'log', 'none'], default='log')
 
@@ -26,8 +26,8 @@ def pytest_configure(config):
         # Deprecation warnings are ignored by default
         pass
 
-    if config.getoption('postgres'):
-        os.environ['DATABASE_ENGINE'] = 'django.db.backends.postgresql_psycopg2'
-        os.environ['DATABASE_NAME'] = 'oscar'
+    if config.getoption('sqlite'):
+        os.environ['DATABASE_ENGINE'] = 'django.db.backends.sqlite3'
+        os.environ['DATABASE_NAME'] = ':memory:'
 
-    django.setup()
+    django.setup()

tests/settings.py

@@ -10,9 +10,9 @@
 
 DATABASES = {
     'default': {
-        'ENGINE': os.environ.get('DATABASE_ENGINE', 'django.db.backends.sqlite3'),
-        'NAME': os.environ.get('DATABASE_NAME', ':memory:'),
-    },
+        'ENGINE': os.environ.get('DATABASE_ENGINE', 'django.db.backends.postgresql_psycopg2'),
+        'NAME': os.environ.get('DATABASE_NAME', 'oscar'),
+    }
 }
 
 INSTALLED_APPS = [