feat(nimbus): Support pausing Firefox Labs deliveries

Because:

- we are going to graduate our first Firefox Labs feature into a real
  feature (auto-pip);
- we want to prevent additional enrollment in the feature when we
  graduate this feature in Firefox 147; and
- we can accomplish this via supporting ending enrollment for Firefox
  Labs delivries

this commit:

- adds support for ending enrollment to Firefox Labs rollouts; and
- adds additional error handling to the LiveToEndEnrollmentForm to
  prevent updating the status via a stale page.

Fixes #14064

Author: freshstrangemusic

experimenter/experimenter/experiments/constants.py

@@ -1232,6 +1232,16 @@ class FirefoxLabsGroups(models.TextChoices):
     ERROR_FIREFOX_LABS_REQUIRED_FIELD = "This field is requried for Firefox Labs Opt-Ins."
     ERROR_FIREFOX_LABS_ROLLOUT_REQUIRED = "Firefox Labs opt-ins must be rollouts."
 
+    ERROR_CANNOT_PAUSE_NOT_LIVE = "Cannot end enrollment: experiment is not live"
+    ERROR_CANNOT_PAUSE_UNPUBLISHED = (
+        "Cannot end enrollment: there are unpublished changes"
+    )
+    ERROR_CANNOT_PAUSE_PAUSED = "Cannot end enrollment: enrollment has already ended"
+    ERROR_CANNOT_PAUSE_ROLLOUT = (
+        "Cannot end enrollment: rollouts do not support this behaviour"
+    )
+    ERROR_CANNOT_PAUSE_INVALID = "Cannot end enrollment at this time"
+
 
 EXTERNAL_URLS = {
     "SIGNOFF_QA": "https://experimenter.info/qa-sign-off",

experimenter/experimenter/experiments/models.py

@@ -819,6 +819,10 @@ def is_review_timeline(self):
             self.PublishStatus.WAITING,
         }
 
+    @property
+    def is_draft(self):
+        return self.status == self.Status.DRAFT
+
     @property
     def is_preview(self):
         return self.status == self.Status.PREVIEW
@@ -911,7 +915,9 @@ def should_show_timeout_message(self):
 
     @property
     def should_show_end_enrollment(self):
-        return self.is_enrolling and not self.is_rollout
+        # If these conditions change then you must update
+        # `LiveToEndEnrollmentForm.clean`.
+        return self.is_enrolling and (not self.is_rollout or self.is_firefox_labs_opt_in)
 
     @property
     def should_show_end_experiment(self):
@@ -1148,7 +1154,7 @@ def computed_observations_days(self):
 
     @property
     def is_live_rollout(self):
-        return self.is_rollout and self.is_enrolling
+        return self.is_rollout and (self.is_enrolling or self.is_observation)
 
     @property
     def is_missing_takeaway_info(self):
@@ -1168,7 +1174,7 @@ def can_edit_metrics(self):
         return self.is_draft
 
     def can_edit_audience(self):
-        return self.is_draft or self.is_live_rollout
+        return self.is_draft or (self.is_live_rollout and self.is_enrolling)
 
     def sidebar_links(self, current_path):
         return [

experimenter/experimenter/nimbus_ui/forms.py

@@ -1412,6 +1412,27 @@ class LiveToEndEnrollmentForm(UpdateStatusForm):
     publish_status = NimbusExperiment.PublishStatus.REVIEW
     is_paused = True
 
+    def clean(self):
+        if self.instance and self.instance.is_rollout_dirty:
+            raise forms.ValidationError(NimbusExperiment.ERROR_CANNOT_PAUSE_UNPUBLISHED)
+        elif not self.instance.should_show_end_enrollment:
+            if (
+                self.instance.is_draft
+                or self.instance.is_preview
+                or self.instance.is_complete
+            ):
+                raise forms.ValidationError(NimbusExperiment.ERROR_CANNOT_PAUSE_NOT_LIVE)
+            elif not self.instance.is_enrolling:
+                raise forms.ValidationError(NimbusExperiment.ERROR_CANNOT_PAUSE_PAUSED)
+            elif self.instance.is_rollout and not self.instance.is_firefox_labs_opt_in:
+                raise forms.ValidationError(NimbusExperiment.ERROR_CANNOT_PAUSE_ROLLOUT)
+            else:  # pragma: nocover
+                # The conditions for Experiment.should_show_enrollment have
+                # changed but this function has become out of sync.
+                raise forms.ValidationError(NimbusExperiment.ERROR_CANNOT_PAUSE_INVALID)
+
+        return super().clean()
+
     def get_changelog_message(self):
         return f"{self.request.user} requested review to end enrollment"
 

experimenter/experimenter/nimbus_ui/templates/nimbus_experiments/launch_controls.html

@@ -27,6 +27,17 @@
       </p>
     </div>
   {% endif %}
+  {% if update_status_form_errors %}
+    <div class="alert alert-danger" role="alert">
+      <p class="mb-1">
+        Could not request an update for this experiment:
+      </p>
+      {{ update_status_form_errors }}
+      <p class="mb-0">
+        Please fix the above issues or ask in <code>#ask-experimenter</code>.
+      </p>
+    </div>
+  {% endif %}
   {% with rejection=experiment.rejection_block %}
     {% if rejection %}
       <div class="alert alert-warning"
@@ -243,7 +254,8 @@ <h5 class="mb-3 ms-2">Actions</h5>
                     hx-select="#content"
                     hx-target="#content"
                     hx-swap="outerHTML"
-                    class="btn btn-primary m-2 end-enrollment_btn">End Enrollment</button>
+                    class="btn btn-primary m-1 end-enrollment_btn"
+                    {% if experiment.is_rollout_dirty %}disabled{% endif %}>End Enrollment</button>
           {% endif %}
           {% if experiment.should_show_end_experiment %}
             <button type="button"
@@ -252,7 +264,7 @@ <h5 class="mb-3 ms-2">Actions</h5>
                     hx-target="#content"
                     hx-swap="outerHTML"
                     id="end-experiment"
-                    class="btn btn-primary end_experiment_btn">
+                    class="btn btn-primary m-1 end_experiment_btn">
               End
               {% if experiment.is_rollout %}
                 Rollout
@@ -267,7 +279,7 @@ <h5 class="mb-3 ms-2">Actions</h5>
                     hx-select="#content"
                     hx-target="#content"
                     hx-swap="outerHTML"
-                    class="btn btn-primary"
+                    class="btn btn-primary m-1"
                     id="request-update-button"
                     {% if not experiment.is_rollout_dirty %}disabled{% endif %}>Request Update</button>
           {% endif %}

experimenter/experimenter/nimbus_ui/tests/test_forms.py

@@ -893,6 +893,88 @@ def test_live_to_end_enrollment_form(self):
         self.assertEqual(changelog.changed_by, self.user)
         self.assertIn("requested review to end enrollment", changelog.message)
 
+    def test_live_to_end_enrollment_form_rollout(self):
+        rollout = NimbusExperimentFactory.create_with_lifecycle(
+            NimbusExperimentFactory.Lifecycles.LIVE_ENROLLING, is_rollout=True
+        )
+
+        form = LiveToEndEnrollmentForm(data={}, instance=rollout, request=self.request)
+        self.assertFalse(form.is_valid())
+        self.assertEqual(
+            form.errors, {"__all__": [NimbusExperiment.ERROR_CANNOT_PAUSE_ROLLOUT]}
+        )
+
+    def test_live_to_end_enrollment_form_firefox_labs(self):
+        rollout = NimbusExperimentFactory.create_with_lifecycle(
+            NimbusExperimentFactory.Lifecycles.LIVE_ENROLLING,
+            is_rollout=True,
+            is_firefox_labs_opt_in=True,
+            firefox_labs_title="title",
+            firefox_labs_description="description",
+            firefox_labs_group="group",
+        )
+
+        form = LiveToEndEnrollmentForm(data={}, instance=rollout, request=self.request)
+        self.assertTrue(form.is_valid(), form.errors)
+
+        rollout = form.save()
+        self.assertEqual(rollout.status, NimbusExperiment.Status.LIVE)
+        self.assertEqual(rollout.status_next, NimbusExperiment.Status.LIVE)
+        self.assertEqual(rollout.publish_status, NimbusExperiment.PublishStatus.REVIEW)
+        self.assertTrue(rollout.is_paused)
+
+        changelog = rollout.changes.latest("changed_on")
+        self.assertEqual(changelog.changed_by, self.user)
+        self.assertIn("requested review to end enrollment", changelog.message)
+
+    def test_live_to_end_enrollment_form_firefox_labs_dirty(self):
+        rollout = NimbusExperimentFactory.create_with_lifecycle(
+            NimbusExperimentFactory.Lifecycles.LIVE_ENROLLING,
+            is_rollout=True,
+            is_firefox_labs_opt_in=True,
+            firefox_labs_title="title",
+            firefox_labs_description="description",
+            firefox_labs_group="group",
+            is_rollout_dirty=True,
+        )
+
+        form = LiveToEndEnrollmentForm(data={}, instance=rollout, request=self.request)
+        self.assertFalse(form.is_valid())
+        self.assertEqual(
+            form.errors, {"__all__": [NimbusExperiment.ERROR_CANNOT_PAUSE_UNPUBLISHED]}
+        )
+
+    def test_live_to_end_enrollment_form_paused(self):
+        experiment = NimbusExperimentFactory.create(
+            status=NimbusExperimentFactory.Lifecycles.LIVE_PAUSED,
+            status_next=None,
+            publish_status=NimbusExperiment.PublishStatus.IDLE,
+        )
+
+        form = LiveToEndEnrollmentForm(data={}, instance=experiment, request=self.request)
+        self.assertFalse(form.is_valid())
+
+        self.assertEqual(
+            form.errors, {"__all__": [NimbusExperiment.ERROR_CANNOT_PAUSE_PAUSED]}
+        )
+
+    @parameterized.expand(
+        [
+            NimbusExperimentFactory.Lifecycles.CREATED,
+            NimbusExperimentFactory.Lifecycles.PREVIEW,
+            NimbusExperimentFactory.Lifecycles.ENDING_APPROVE_APPROVE,
+        ]
+    )
+    def test_live_to_end_enrollment_form_not_live(self, lifecycle):
+        experiment = NimbusExperimentFactory.create_with_lifecycle(lifecycle)
+
+        form = LiveToEndEnrollmentForm(data={}, instance=experiment, request=self.request)
+        self.assertFalse(form.is_valid())
+
+        self.assertEqual(
+            form.errors, {"__all__": [NimbusExperiment.ERROR_CANNOT_PAUSE_NOT_LIVE]}
+        )
+
     def test_approve_end_enrollment_form(self):
         experiment = NimbusExperimentFactory.create(
             status=NimbusExperiment.Status.LIVE,

experimenter/experimenter/nimbus_ui/views.py

@@ -602,6 +602,14 @@ class FeatureUnsubscribeView(FeatureSubscriberViewMixin):
 class StatusUpdateView(RequestFormMixin, RenderResponseMixin, NimbusExperimentDetailView):
     fields = None
 
+    def get_context_data(self, *, form, **kwargs):
+        context = super().get_context_data(form=form, **kwargs)
+
+        if self.request.method in ("POST", "PUT") and not form.is_valid():
+            context["update_status_form_errors"] = form.errors["__all__"]
+
+        return context
+
 
 class DraftToPreviewView(StatusUpdateView):
     form_class = DraftToPreviewForm