prevent panics when waitgroup == nil (#1423)

internal/scheduler/scheduler.go

@@ -138,6 +138,12 @@ func (s *Scheduler) Start(ctx context.Context, wg *sync.WaitGroup) error {
 		event.WriteSysEvent(ctx, op, "scheduler already started, skipping")
 		return nil
 	}
+	if ctx == nil {
+		return errors.New(errors.InvalidParameter, op, "missing context")
+	}
+	if wg == nil {
+		return errors.New(errors.InvalidParameter, op, "missing wait group")
+	}
 
 	if err := ctx.Err(); err != nil {
 		return errors.Wrap(err, op)
@@ -154,9 +160,7 @@ func (s *Scheduler) Start(ctx context.Context, wg *sync.WaitGroup) error {
 		return errors.Wrap(err, op)
 	}
 
-	if wg != nil {
-		wg.Add(2)
-	}
+	wg.Add(2)
 	go func() {
 		defer wg.Done()
 		s.start(ctx)

internal/scheduler/scheduler_test.go

@@ -2,6 +2,7 @@ package scheduler
 
 import (
 	"context"
+	"sync"
 	"testing"
 	"time"
 
@@ -366,3 +367,54 @@ func TestScheduler_UpdateJobNextRunInAtLeast(t *testing.T) {
 		assert.Equal(previousNextRun.Add(-1*time.Hour).Round(time.Minute), dbJob.NextScheduledRun.AsTime().Round(time.Minute))
 	})
 }
+
+func TestScheduler_Start(t *testing.T) {
+	t.Parallel()
+	conn, _ := db.TestSetup(t, "postgres")
+	wrapper := db.TestWrapper(t)
+	iam.TestRepo(t, conn, wrapper)
+
+	sched := TestScheduler(t, conn, wrapper)
+
+	tests := []struct {
+		name            string
+		ctx             context.Context
+		wg              *sync.WaitGroup
+		wantErr         bool
+		wantErrContains string
+	}{
+
+		{
+			name:            "missing-ctx",
+			wg:              &sync.WaitGroup{},
+			wantErr:         true,
+			wantErrContains: "missing context",
+		},
+		{
+			name:            "missing-waitgroup",
+			ctx:             context.Background(),
+			wantErr:         true,
+			wantErrContains: "missing wait group",
+		},
+
+		{
+			name: "valid",
+			ctx:  context.Background(),
+			wg:   &sync.WaitGroup{},
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			assert, require := assert.New(t), require.New(t)
+			err := sched.Start(tt.ctx, tt.wg)
+			if tt.wantErr {
+				require.Error(err)
+				if tt.wantErrContains != "" {
+					assert.Contains(err.Error(), tt.wantErrContains)
+				}
+				return
+			}
+			require.NoError(err)
+		})
+	}
+}