Filter out invalid JST in ReconcileDifferences (#3911)

* Filter out invalid JST in ReconcileDifferences (#221)

* lint

Signed-off-by: Chris Martin <chris@cmartinit.co.uk>

---------

Signed-off-by: Chris Martin <chris@cmartinit.co.uk>
Co-authored-by: Christopher Martin <Chris.Martin@gresearch.co.uk>

internal/scheduler/jobdb/reconciliation.go

@@ -78,13 +78,19 @@ func (jobDb *JobDb) ReconcileDifferences(txn *Txn, jobRepoJobs []database.Job, j
 
 	jsts := make([]JobStateTransitions, 0, len(jobRepoJobsById))
 	for jobId, jobRepoJob := range jobRepoJobsById {
-		if jst, err := jobDb.reconcileJobDifferences(
+		jst, err := jobDb.reconcileJobDifferences(
 			txn.GetById(jobId),     // Existing job in the jobDb.
 			jobRepoJob,             // New or updated job from the jobRepo.
 			jobRepoRunsById[jobId], // New or updated runs associated with this job from the jobRepo.
-		); err != nil {
+		)
+		if err != nil {
 			return nil, err
-		} else {
+		}
+
+		// We receive nil jobs from jobDb.ReconcileDifferences if a run is updated after the associated job is deleted.
+		// In this case it is safe to ignore the jst.
+		// TODO: don't generate a jst in the first place if this is the case!
+		if jst.Job != nil {
 			jsts = append(jsts, jst)
 		}
 	}

internal/scheduler/scheduler.go

@@ -373,11 +373,7 @@ func (s *Scheduler) syncState(ctx *armadacontext.Context) ([]*jobdb.Job, []jobdb
 	// Upsert updated jobs (including associated runs).
 	jobDbJobs := make([]*jobdb.Job, 0, len(jsts))
 	for _, jst := range jsts {
-		if jst.Job != nil {
-			// We receive nil jobs from jobDb.ReconcileDifferences if a run is updated after the associated job is deleted.
-			// These nil job must be sorted out.
-			jobDbJobs = append(jobDbJobs, jst.Job)
-		}
+		jobDbJobs = append(jobDbJobs, jst.Job)
 	}
 	if err := txn.Upsert(jobDbJobs); err != nil {
 		return nil, nil, err