Sorting by channel does not sort alphabetically fixes #1042

app/experimenter/experiments/constants.py

@@ -85,6 +85,12 @@ class ExperimentConstants(object):
         (CHANNEL_RELEASE, CHANNEL_RELEASE),
     )
 
+    # Ordering given in https://github.com/mozilla/experimenter/issues/1042
+    CHANNEL_NIGHTLY_ORDER = 1
+    CHANNEL_BETA_ORDER = 2
+    CHANNEL_RELEASE_ORDER = 3
+    CHANNEL_UNSET_ORDER = 0
+
     # Pref stuff
     PREF_TYPE_BOOL = "boolean"
     PREF_TYPE_INT = "integer"

app/experimenter/experiments/models.py

@@ -7,7 +7,7 @@
 from django.contrib.postgres.fields import JSONField
 from django.core.validators import MaxValueValidator
 from django.db import models
-from django.db.models import Max
+from django.db.models import Case, Max, Value, When
 from django.urls import reverse
 from django.utils import timezone
 from django.utils.functional import cached_property
@@ -511,6 +511,26 @@ def population(self):
             channel=self.firefox_channel,
         )
 
+    @staticmethod
+    def firefox_channel_sort():
+        """A Case that can be added to an Experiment QuerySet to sort."""
+        return Case(
+            When(
+                firefox_channel=ExperimentConstants.CHANNEL_RELEASE,
+                then=Value(ExperimentConstants.CHANNEL_RELEASE_ORDER),
+            ),
+            When(
+                firefox_channel=ExperimentConstants.CHANNEL_BETA,
+                then=Value(ExperimentConstants.CHANNEL_BETA_ORDER),
+            ),
+            When(
+                firefox_channel=ExperimentConstants.CHANNEL_NIGHTLY,
+                then=Value(ExperimentConstants.CHANNEL_NIGHTLY_ORDER),
+            ),
+            default=Value(ExperimentConstants.CHANNEL_UNSET_ORDER),
+            output_field=models.IntegerField(),
+        )
+
 
 class ExperimentVariant(models.Model):
     experiment = models.ForeignKey(

app/experimenter/experiments/tests/test_models.py

@@ -838,6 +838,28 @@ def test_experiment_population_returns_correct_string(self):
         )
         self.assertEqual(experiment.population, "0.5% of Nightly Firefox 57.0")
 
+    def test_experiment_firefox_channel_sort_does_sorting(self):
+        ExperimentFactory.create(firefox_channel=Experiment.CHANNEL_NIGHTLY)
+        ExperimentFactory.create(firefox_channel=Experiment.CHANNEL_RELEASE)
+        ExperimentFactory.create(firefox_channel=Experiment.CHANNEL_BETA)
+        ExperimentFactory.create(firefox_channel="")
+        sorted_experiments = (
+            Experiment.objects.annotate(
+                firefox_channel_sort=Experiment.firefox_channel_sort()
+            )
+            .order_by("firefox_channel_sort")
+            .values("firefox_channel_sort")
+        )
+        self.assertEqual(
+            [r["firefox_channel_sort"] for r in sorted_experiments],
+            [
+                Experiment.CHANNEL_UNSET_ORDER,
+                Experiment.CHANNEL_NIGHTLY_ORDER,
+                Experiment.CHANNEL_BETA_ORDER,
+                Experiment.CHANNEL_RELEASE_ORDER,
+            ],
+        )
+
 
 class TestExperimentChangeLog(TestCase):
 

app/experimenter/experiments/views.py

@@ -111,8 +111,8 @@ class ExperimentOrderingForm(forms.Form):
         ("latest_change", "Least Recently Updated"),
         ("firefox_version", "Firefox Version Ascending"),
         ("-firefox_version", "Firefox Version Descending"),
-        ("firefox_channel", "Firefox Channel Ascending"),
-        ("-firefox_channel", "Firefox Channel Descending"),
+        ("firefox_channel_sort", "Firefox Channel Ascending"),
+        ("-firefox_channel_sort", "Firefox Channel Descending"),
     )
 
     ordering = forms.ChoiceField(
@@ -141,6 +141,13 @@ def get_filterset_kwargs(self, *args, **kwargs):
         kwargs["data"] = self.request.GET
         return kwargs
 
+    def get_queryset(self):
+        qs = super().get_queryset()
+        qs = qs.annotate(
+            firefox_channel_sort=Experiment.firefox_channel_sort()
+        )
+        return qs
+
     def get_ordering(self):
         self.ordering_form = ExperimentOrderingForm(self.request.GET)