chore(nimbus): use cached dates in csv reports (#13818)

Because

* Generating the CSV report for all current/past experiments can be very
slow
* One of the slowest parts is looking up all the start/end dates
* Since we added the CSV report, we have added cache fields for both
start/end date
* Using the cached fields should greatly speedup the CSV report
generation

This commit

* Switches the CSV report to use the cached start/end dates

fixes #13810

Author: jaredlockhart

docs/experimenter/openapi-schema.json

@@ -4073,17 +4073,19 @@
             "type": "string",
             "readOnly": true
           },
-          "start_date": {
+          "_start_date": {
             "type": "string",
-            "readOnly": true
+            "format": "date",
+            "nullable": true
           },
           "enrollment_duration": {
             "type": "string",
             "readOnly": true
           },
-          "end_date": {
+          "_end_date": {
             "type": "string",
-            "readOnly": true
+            "format": "date",
+            "nullable": true
           },
           "results_url": {
             "type": "string",

docs/experimenter/swagger-ui.html

@@ -4085,17 +4085,19 @@
             "type": "string",
             "readOnly": true
           },
-          "start_date": {
+          "_start_date": {
             "type": "string",
-            "readOnly": true
+            "format": "date",
+            "nullable": true
           },
           "enrollment_duration": {
             "type": "string",
             "readOnly": true
           },
-          "end_date": {
+          "_end_date": {
             "type": "string",
-            "readOnly": true
+            "format": "date",
+            "nullable": true
           },
           "results_url": {
             "type": "string",

experimenter/experimenter/experiments/api/v5/serializers.py

@@ -1099,9 +1099,9 @@ class Meta:
             "experiment_name",
             "owner",
             "feature_configs",
-            "start_date",
+            "_start_date",
             "enrollment_duration",
-            "end_date",
+            "_end_date",
             "results_url",
             "experiment_summary",
             "rollout",

experimenter/experimenter/experiments/tests/api/v5/test_serializers/test_nimbus_experiment_csv_serializer.py

@@ -11,52 +11,20 @@
 
 
 class TestNimbusExperimentCsvSerializer(TestCase):
-    def test_serializer_outputs_expected_schema(self):
-        application = NimbusExperiment.Application.DESKTOP
-        feature_config = NimbusFeatureConfigFactory.create(application=application)
-
-        experiment = NimbusExperimentFactory.create(
-            application=application, feature_configs=[feature_config]
-        )
-
-        serializer = NimbusExperimentCsvSerializer(experiment)
-        self.assertDictEqual(
-            serializer.data,
-            {
-                "launch_month": experiment.launch_month,
-                "product_area": experiment.application.value,
-                "experiment_name": experiment.name,
-                "owner": experiment.owner.email,
-                "feature_configs": feature_config.name,
-                "start_date": experiment.start_date,
-                "enrollment_duration": experiment.enrollment_duration,
-                "end_date": experiment.end_date,
-                "results_url": "",
-                "experiment_summary": experiment.experiment_url,
-                "rollout": experiment.is_rollout,
-                "hypothesis": experiment.hypothesis,
-                "takeaways_metric_gain": experiment.takeaways_metric_gain,
-                "takeaways_gain_amount": experiment.takeaways_gain_amount,
-                "takeaways_qbr_learning": experiment.takeaways_qbr_learning,
-                "takeaways_summary": experiment.takeaways_summary,
-            },
-        )
+    maxDiff = None
 
     def test_serializer_outputs_expected_schema_with_results_link(self):
         application = NimbusExperiment.Application.DESKTOP
         feature_config = NimbusFeatureConfigFactory.create(application=application)
 
         experiment = NimbusExperimentFactory.create_with_lifecycle(
-            NimbusExperimentFactory.Lifecycles.LAUNCH_APPROVE_APPROVE,
+            NimbusExperimentFactory.Lifecycles.ENDING_APPROVE_APPROVE,
             application=application,
             feature_configs=[feature_config],
+            start_date=datetime.date(2019, 5, 1),
+            end_date=datetime.date(2019, 5, 2),
         )
-        experiment.changes.all().filter(
-            old_status=NimbusExperiment.Status.DRAFT,
-            new_status=NimbusExperiment.Status.LIVE,
-        ).update(
-            changed_on=datetime.date(2019, 5, 1),
-        )
+
         serializer = NimbusExperimentCsvSerializer(experiment)
         self.assertDictEqual(
             serializer.data,
@@ -66,9 +34,9 @@ def test_serializer_outputs_expected_schema_with_results_link(self):
                 "experiment_name": experiment.name,
                 "owner": experiment.owner.email,
                 "feature_configs": feature_config.name,
-                "start_date": experiment.start_date,
+                "_start_date": "2019-05-01",
                 "enrollment_duration": experiment.enrollment_duration,
-                "end_date": experiment.end_date,
+                "_end_date": "2019-05-02",
                 "results_url": f"{experiment.experiment_url}results",
                 "experiment_summary": experiment.experiment_url,
                 "rollout": experiment.is_rollout,