Add a simple test mode (#1181)

- [x] Provide data model and configuration toggle
- [x] Allow to delete individual test orders
- [x] Add tests
- [x] Add a prominent warning message to the backend if test mode orders exist (even though test mode is off), as this leads to wrong statistics
- [x] Decide if and how to generate invoices for test orders as invoice numbers cannot be repeated or should not have gaps.
- [x] Decide if and how we expose test orders through the API, since our difference pull mechanism relies on the fact that orders cannot be deleted.
- [x] Decide if and how we want to couple test modes of payment providers?
- [ ] pretix.eu: Ignore test orders for billing
- [ ] Adjust payment providers: Mollie, bitpay, cash, fakepayment, sepadebit

![download](https://user-images.githubusercontent.com/64280/53009081-fe420d80-343a-11e9-8361-b8511c988598.png)

src/pretix/plugins/banktransfer/payment.py

@@ -101,6 +101,11 @@ class BankTransfer(BasePaymentProvider):
     def public_name(self):
         return str(self.settings.get('public_name', as_type=LazyI18nString) or self.verbose_name)
 
+    @property
+    def test_mode_message(self):
+        return _('In test mode, you can just manually mark this order as paid in the backend after it has been '
+                 'created.')
+
     @property
     def settings_form_fields(self):
         d = OrderedDict(

src/pretix/plugins/paypal/payment.py

@@ -36,6 +36,18 @@ class Paypal(BasePaymentProvider):
         super().__init__(event)
         self.settings = SettingsSandbox('payment', 'paypal', event)
 
+    @property
+    def test_mode_message(self):
+        if self.settings.connect_client_id and not self.settings.secret:
+            # in OAuth mode, sandbox mode needs to be set global
+            is_sandbox = self.settings.connect_endpoint == 'sandbox'
+        else:
+            is_sandbox = self.settings.get('endpoint') == 'sandbox'
+        if is_sandbox:
+            return _('The PayPal sandbox is being used, you can test without actually sending money but you will need a '
+                     'PayPal sandbox user to log in.')
+        return None
+
     @property
     def settings_form_fields(self):
         if self.settings.connect_client_id and not self.settings.secret:

src/pretix/plugins/pretixdroid/templates/pretixplugins/pretixdroid/configuration_code.html

@@ -63,6 +63,11 @@
         </p>
         <h2>{% trans "3. Start scanning tickets" %}</h2>
         <script type="text/javascript" src="{% static "pretixplugins/pretixdroid/pretixdroid.js" %}"></script>
+        {% if request.event.testmode %}
+            <div class="alert-info">
+                {% trans "Test mode orders will only be scanned if you scan online. If you scan in asynchronous mode, test mode orders won't be there." %}
+            </div>
+        {% endif %}
     {% endif %}
 {% endblock %}
 

src/pretix/plugins/pretixdroid/views.py

@@ -332,6 +332,7 @@ class ApiDownloadView(ApiView):
             order__event=self.event,
             order__status__in=[Order.STATUS_PAID] + ([Order.STATUS_PENDING] if self.config.list.include_pending else
                                                      []),
+            order__testmode=False,
             subevent=self.config.list.subevent
         ).annotate(
             last_checked_in=Subquery(cqs)

src/pretix/plugins/stripe/payment.py

@@ -14,6 +14,7 @@ from django.template.loader import get_template
 from django.urls import reverse
 from django.utils.crypto import get_random_string
 from django.utils.http import urlquote
+from django.utils.safestring import mark_safe
 from django.utils.timezone import now
 from django.utils.translation import pgettext, ugettext, ugettext_lazy as _
 from django_countries import countries
@@ -111,6 +112,8 @@ class StripeSettingsHolder(BasePaymentProvider):
                              ('live', pgettext('stripe', 'Live')),
                              ('test', pgettext('stripe', 'Testing')),
                          ),
+                         help_text=_('If your event is in test mode, we will always use Stripe\'s test API, '
+                                     'regardless of this setting.')
                      )),
                 ]
             else:
@@ -230,6 +233,21 @@ class StripeMethod(BasePaymentProvider):
         super().__init__(event)
         self.settings = SettingsSandbox('payment', 'stripe', event)
 
+    @property
+    def test_mode_message(self):
+        if self.settings.connect_client_id and not self.settings.secret_key:
+            is_testmode = True
+        else:
+            is_testmode = '_test_' in self.settings.secret_key
+        if is_testmode:
+            return mark_safe(
+                _('The Stripe plugin is operating in test mode. You can use one of <a {args}>many test '
+                  'cards</a> to perform a transaction. No money will actually be transferred.').format(
+                    args='href="https://stripe.com/docs/testing#cards" target="_blank"'
+                )
+            )
+        return None
+
     @property
     def settings_form_fields(self):
         return {}
@@ -262,7 +280,7 @@ class StripeMethod(BasePaymentProvider):
     @property
     def api_kwargs(self):
         if self.settings.connect_client_id and self.settings.connect_user_id:
-            if self.settings.get('endpoint', 'live') == 'live':
+            if self.settings.get('endpoint', 'live') == 'live' and not self.event.testmode:
                 kwargs = {
                     'api_key': self.settings.connect_secret_key,
                     'stripe_account': self.settings.connect_user_id