Also clear the schedule cache for recomputation, when the task date h…

…as changed.

This happens (without changing the try number) when the task has been cleared.

Later we will also address https://dfinity.atlassian.net/browse/DRE-304 .
This is a very small prelude to that, covering a corner case we were not covering
before.

rollout-dashboard/server/src/frontend_api.rs

@@ -256,7 +256,11 @@ impl From<CyclicDependencyError> for RolloutDataGatherError {
 #[derive(Clone, Serialize)]
 enum ScheduleCache {
     Empty,
-    Valid(usize, String),
+    Valid {
+        try_number: usize,
+        task_date: DateTime<Utc>,
+        cached_schedule: String,
+    },
 }
 
 struct RolloutDataCache {
@@ -635,15 +639,24 @@ impl RolloutApi {
                         | Some(TaskInstanceState::Scheduled)
                         | None => rollout.state = min(rollout.state, RolloutState::Preparing),
                         Some(TaskInstanceState::Success) => {
-                            if let ScheduleCache::Valid(try_number, _) = cache_entry.schedule {
-                                if try_number != task_instance.try_number {
+                            if let ScheduleCache::Valid {
+                                try_number,
+                                task_date,
+                                ..
+                            } = cache_entry.schedule
+                            {
+                                if try_number != task_instance.try_number
+                                    || task_date != task_instance.latest_date()
+                                {
                                     info!(target: "frontend_api", "{}: resetting schedule cache", dag_run.dag_run_id);
                                     // Another task run of the same task has executed.  We must clear the cache entry.
                                     cache_entry.schedule = ScheduleCache::Empty;
                                 }
                             }
                             let schedule_string = match &cache_entry.schedule {
-                                ScheduleCache::Valid(_, s) => s,
+                                ScheduleCache::Valid {
+                                    cached_schedule, ..
+                                } => cached_schedule,
                                 ScheduleCache::Empty => {
                                     let value = self
                                         .airflow_api
@@ -657,10 +670,11 @@ impl RolloutApi {
                                         .await;
                                     let schedule = match value {
                                         Ok(schedule) => {
-                                            cache_entry.schedule = ScheduleCache::Valid(
-                                                task_instance.try_number,
-                                                schedule.value.clone(),
-                                            );
+                                            cache_entry.schedule = ScheduleCache::Valid {
+                                                try_number: task_instance.try_number,
+                                                task_date: task_instance.latest_date(),
+                                                cached_schedule: schedule.value.clone(),
+                                            };
                                             info!(target: "frontend_api", "{}: saving schedule cache", dag_run.dag_run_id);
                                             schedule.value
                                         }