Move in-page script to tracker.js (#73)

* Remove inline script

* Lint

* Add tests

wagtail_ab_testing/static/wagtail_ab_testing/js/tracker.js

@@ -7,6 +7,14 @@
         }
     }
 
+    // Read the tracking parameters from JSON script
+    let trackingParams = null;
+    if (document.getElementById('abtesting-tracking-params')) {
+        trackingParams = JSON.parse(document.getElementById('abtesting-tracking-params').textContent);
+        // Attach the wagtailAbTesting object to the window
+        window.wagtailAbTesting = trackingParams;
+    }
+
     function getCookie(cookieName) {
         var cookies = document.cookie.split(';');
         for (var i = 0; i < cookies.length; i++) {

wagtail_ab_testing/templates/wagtail_ab_testing/script.html

@@ -1,30 +1,6 @@
 {% load static %}
 
 {% if track %}
-    <script>
-        window.wagtailAbTesting = {
-            {# Is this a Wagtail Page? #}
-            {# This value is used to check if a goal has been reached #}
-            {% if page %}
-            pageId: {{ page.id }},
-            {% endif %}
-
-            {# Is there a test running on the current page? #}
-            {% if test and version %}
-            testId: {{ test.id }},
-            version: '{{ version|escapejs }}',
-            goalEvent: '{{ test.goal_event|escapejs }}',
-            goalPageId: {% if test.goal_page %}{{ test.goal_page.id }}{% else %}null{% endif %},
-            {% endif %}
-
-            urls: {
-                {% url 'wagtail_ab_testing:register_participant' as register_participant_url %}
-                registerParticipant: '{{ register_participant_url|escapejs }}',
-                {% url 'wagtail_ab_testing:goal_reached' as goal_reached_url %}
-                goalReached: '{{ goal_reached_url|escapejs }}',
-            }
-        };
-    </script>
-
+    {{ tracking_parameters|json_script:"abtesting-tracking-params" }}
     <script src="{% static 'wagtail_ab_testing/js/tracker.js' %}" defer async></script>
 {% endif %}

wagtail_ab_testing/templatetags/wagtail_ab_testing_tags.py

@@ -1,4 +1,5 @@
 from django import template
+from django.urls import reverse
 
 from wagtail_ab_testing.models import AbTest
 from wagtail_ab_testing.utils import request_is_trackable
@@ -11,9 +12,38 @@ def wagtail_ab_testing_script(context):
     request = context['request']
     serving_variant = getattr(request, 'wagtail_ab_testing_serving_variant', False)
 
+    track = request_is_trackable(request)
+    if not track:
+        return {
+            "track": False,
+            "tracking_parameters": None,
+        }
+
+    register_participant_url = reverse('wagtail_ab_testing:register_participant')
+    goal_reached_url = reverse('wagtail_ab_testing:goal_reached')
+
+    tracking_parameters = {
+        "urls": {
+            "registerParticipant": register_participant_url,
+            "goalReached": goal_reached_url,
+        },
+    }
+
+    page = context.get('page', None)
+    page_id = page.id if page else None
+    if page_id:
+        tracking_parameters["pageId"] = page_id
+
+    version = AbTest.VERSION_VARIANT if serving_variant else AbTest.VERSION_CONTROL
+    test = getattr(request, 'wagtail_ab_testing_test', None)
+
+    if (test and version):
+        tracking_parameters["testId"] = test.id
+        tracking_parameters["version"] = version
+        tracking_parameters["goalEvent"] = test.goal_event
+        tracking_parameters["goalPageId"] = test.goal_page.id if test.goal_page else None
+
     return {
-        'track': request_is_trackable(request),
-        'page': context.get('page', None),
-        'test': getattr(request, 'wagtail_ab_testing_test', None),
-        'version': AbTest.VERSION_VARIANT if serving_variant else AbTest.VERSION_CONTROL,
+        'track': track,
+        'tracking_parameters': tracking_parameters,
     }

wagtail_ab_testing/test/tests/test_templatetags.py

@@ -0,0 +1,184 @@
+from unittest.mock import patch
+
+from django.urls import reverse
+from django.test import RequestFactory, TestCase
+
+from wagtail.models import Page
+
+from wagtail_ab_testing.models import AbTest
+from wagtail_ab_testing.templatetags.wagtail_ab_testing_tags import (
+    wagtail_ab_testing_script,
+)
+
+
+@patch(
+    "wagtail_ab_testing.templatetags.wagtail_ab_testing_tags.request_is_trackable",
+    return_value=True,
+)
+class TestWagtailAbTestingScriptTemplateTag(TestCase):
+    def setUp(self):
+        # Create test page with a draft revision
+        self.page = Page.objects.get(id=2).add_child(
+            instance=Page(title="Test", slug="test")
+        )
+        self.page.title = "Changed title"
+        self.page.save_revision()
+
+        # Create an A/B test
+        self.ab_test = AbTest.objects.create(
+            page=self.page,
+            name="Test",
+            variant_revision=self.page.get_latest_revision(),
+            status=AbTest.STATUS_RUNNING,
+            goal_page_id=2,
+            goal_event="visit-page",
+            sample_size=100,
+        )
+
+        # Create a request factory:
+        self.factory = RequestFactory()
+
+    def test_ab_testing_script_tag_test_with_trackable_urls(
+        self, mock_request_is_callable
+    ):
+        """Test the tag for a page that is part of an A/B test serving a control version."""
+        # A/B test page url:
+        url = (reverse("wagtail_ab_testing:goal_reached", args=[]),)
+        # Create a request
+        request = self.factory.post(
+            url,
+            {
+                "test_id": self.ab_test.id,
+                "version": "control",
+            },
+        )
+
+        request.wagtail_ab_testing_test = self.ab_test
+        request.wagtail_ab_testing_serving_variant = False
+
+        context = {
+            "request": request,
+            "page": self.page,
+        }
+
+        result = wagtail_ab_testing_script(context)
+
+        expected_tracking_parameters = {
+            "urls": {
+                "registerParticipant": reverse(
+                    "wagtail_ab_testing:register_participant"
+                ),
+                "goalReached": reverse("wagtail_ab_testing:goal_reached"),
+            },
+            "pageId": self.page.id,
+            "testId": self.ab_test.id,
+            "version": AbTest.VERSION_CONTROL,
+            "goalEvent": self.ab_test.goal_event,
+            "goalPageId": self.ab_test.goal_page.id,
+        }
+
+        self.assertEqual(result["track"], True)
+        self.assertDictEqual(
+            result["tracking_parameters"], expected_tracking_parameters
+        )
+
+    def test_ab_testing_script_tag_test_serving_variant(self, mock_request_is_callable):
+        """Test the tag for a page serving a variant in an A/B test."""
+        # A/B test page url:
+        url = (reverse("wagtail_ab_testing:goal_reached", args=[]),)
+        # Create a request
+        request = self.factory.post(
+            url,
+            {
+                "test_id": self.ab_test.id,
+                "version": "variant",
+            },
+        )
+
+        request.wagtail_ab_testing_test = self.ab_test
+        request.wagtail_ab_testing_serving_variant = True
+
+        context = {
+            "request": request,
+            "page": self.page,
+        }
+
+        result = wagtail_ab_testing_script(context)
+
+        expected_tracking_parameters = {
+            "urls": {
+                "registerParticipant": reverse(
+                    "wagtail_ab_testing:register_participant"
+                ),
+                "goalReached": reverse("wagtail_ab_testing:goal_reached"),
+            },
+            "pageId": self.page.id,
+            "testId": self.ab_test.id,
+            "version": AbTest.VERSION_VARIANT,
+            "goalEvent": self.ab_test.goal_event,
+            "goalPageId": self.ab_test.goal_page.id,
+        }
+
+        self.assertEqual(result["track"], True)
+        self.assertDictEqual(
+            result["tracking_parameters"], expected_tracking_parameters
+        )
+
+    def test_ab_testing_script_tag_without_test_in_request(
+        self, mock_request_is_callable
+    ):
+        """Test the tag for a page that is not part of an A/B test."""
+        # Create a request for a page that is not part of an A/B test
+        request = self.factory.get("/")
+
+        context = {
+            "request": request,
+            "page": self.page,
+        }
+
+        result = wagtail_ab_testing_script(context)
+
+        expected_tracking_parameters = {
+            "urls": {
+                "registerParticipant": reverse(
+                    "wagtail_ab_testing:register_participant"
+                ),
+                "goalReached": reverse("wagtail_ab_testing:goal_reached"),
+            },
+            "pageId": self.page.id,
+        }
+
+        # There is still a test running and this user is being tracked:
+        self.assertEqual(result["track"], True)
+        self.assertDictEqual(result["tracking_parameters"], expected_tracking_parameters)
+
+    def test_ab_testing_script_tag_request_without_tracking(
+        self, mock_request_is_callable
+    ):
+        """Test the tag for a request that should not be tracked."""
+        # A/B test page url:
+        url = (reverse("wagtail_ab_testing:goal_reached", args=[]),)
+        # Create a request
+        request = self.factory.get(
+            url,
+            {
+                "test_id": self.ab_test.id,
+                "version": "variant",
+            },
+        )
+
+        request.wagtail_ab_testing_test = self.ab_test
+        request.wagtail_ab_testing_serving_variant = True
+
+        context = {
+            "request": request,
+            "page": self.page,
+        }
+
+        # Mock a request from a bot or with a DNT
+        mock_request_is_callable.return_value = False
+
+        result = wagtail_ab_testing_script(context)
+
+        self.assertEqual(result["track"], False)
+        self.assertIsNone(result["tracking_parameters"])