Merge pull request #10 from praekeltfoundation/feature/SAS-92-store-randomisation-percentage

Add randomisation percentage to segment model

src/wagtail_personalisation/migrations/0017_segment_randomisation_percent.py

@@ -0,0 +1,21 @@
+# -*- coding: utf-8 -*-
+# Generated by Django 1.10.8 on 2018-01-31 16:12
+from __future__ import unicode_literals
+
+import django.core.validators
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('wagtail_personalisation', '0016_auto_20180125_0918'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='segment',
+            name='randomisation_percent',
+            field=models.PositiveSmallIntegerField(blank=True, default=None, help_text='If this number is set each user matching the rules will have this percentage chance of being placed in the segment.', null=True, validators=[django.core.validators.MaxValueValidator(100), django.core.validators.MinValueValidator(0)]),
+        ),
+    ]

src/wagtail_personalisation/models.py

@@ -2,6 +2,7 @@ from __future__ import absolute_import, unicode_literals
 
 from django import forms
 from django.conf import settings
+from django.core.validators import MaxValueValidator, MinValueValidator
 from django.db import models, transaction
 from django.template.defaultfilters import slugify
 from django.utils.encoding import python_2_unicode_compatible
@@ -85,6 +86,16 @@ class Segment(ClusterableModel):
     matched_users_count = models.PositiveIntegerField(default=0, editable=False)
     matched_count_updated_at = models.DateTimeField(null=True, editable=False)
 
+    randomisation_percent = models.PositiveSmallIntegerField(
+        null=True, blank=True, default=None,
+        help_text=_(
+            "If this number is set each user matching the rules will "
+            "have this percentage chance of being placed in the segment."
+        ), validators=[
+            MaxValueValidator(100),
+            MinValueValidator(0)
+        ])
+
     objects = SegmentQuerySet.as_manager()
 
     base_form_class = SegmentAdminForm
@@ -100,6 +111,7 @@ class Segment(ClusterableModel):
                 FieldPanel('match_any'),
                 FieldPanel('type', widget=forms.RadioSelect),
                 FieldPanel('count', classname='count_field'),
+                FieldPanel('randomisation_percent', classname='percent_field'),
             ], heading="Segment"),
             MultiFieldPanel([
                 InlinePanel(

src/wagtail_personalisation/templates/modeladmin/wagtail_personalisation/segment/dashboard.html

@@ -70,6 +70,13 @@
                                                     {% endif %}
                                                 </li>
 
+                                                {% if segment.randomisation_percent is not None %}
+                                                    <li class="stat_card">
+                                                        <span>{{ segment.randomisation_percent }} %</span>
+                                                        {% trans "Chance that visitors matching the rules are added to the segment" %}
+                                                    </li>
+                                                {% endif %}
+
                                                 {% for rule in segment.get_rules %}
                                                     <li class="stat_card {{ rule.encoded_name }}">
                                                         {{ rule.description.title }}

tests/unit/test_static_dynamic_segments.py

@@ -13,7 +13,7 @@ from wagtail_personalisation.rules import (AbstractBaseRule, TimeRule,
 
 
 def form_with_data(segment, *rules):
-    model_fields = ['type', 'status', 'count', 'name', 'match_any']
+    model_fields = ['type', 'status', 'count', 'name', 'match_any', 'randomisation_percent']
 
     class TestSegmentAdminForm(SegmentAdminForm):
         class Meta:
@@ -249,6 +249,38 @@ def test_dynamic_segment_with_non_static_rules_have_a_count():
     assert form.is_valid(), form.errors
 
 
+@pytest.mark.django_db
+def test_randomisation_percentage_added_to_segment_at_creation(site, client, mocker, django_user_model):
+    segment = SegmentFactory.build(type=Segment.TYPE_STATIC)
+    segment.randomisation_percent = 80
+    rule = VisitCountRule()
+
+    form = form_with_data(segment, rule)
+    instance = form.save()
+
+    assert instance.randomisation_percent == 80
+
+
+@pytest.mark.django_db
+def test_randomisation_percentage_min_zero(site, client, mocker, django_user_model):
+    segment = SegmentFactory.build(type=Segment.TYPE_STATIC)
+    segment.randomisation_percent = -1
+    rule = VisitCountRule()
+
+    form = form_with_data(segment, rule)
+    assert not form.is_valid()
+
+
+@pytest.mark.django_db
+def test_randomisation_percentage_max_100(site, client, mocker, django_user_model):
+    segment = SegmentFactory.build(type=Segment.TYPE_STATIC)
+    segment.randomisation_percent = 101
+    rule = VisitCountRule()
+
+    form = form_with_data(segment, rule)
+    assert not form.is_valid()
+
+
 @pytest.mark.django_db
 def test_matched_user_count_added_to_segment_at_creation(site, client, mocker, django_user_model):
     django_user_model.objects.create(username='first')