fix(ApplicationSet): Check strategy type to verify it's a progressive sync (cherry-pick #22563)

applicationset/controllers/applicationset_controller.go

@@ -210,16 +210,16 @@ func (r *ApplicationSetReconciler) Reconcile(ctx context.Context, req ctrl.Reque
 	appSyncMap := map[string]bool{}
 
 	if r.EnableProgressiveSyncs {
-		if applicationSetInfo.Spec.Strategy == nil && len(applicationSetInfo.Status.ApplicationStatus) > 0 {
-			// If appset used progressive sync but stopped, clean up the progressive sync application statuses
+		if !isRollingSyncStrategy(&applicationSetInfo) && len(applicationSetInfo.Status.ApplicationStatus) > 0 {
+			// If an appset was previously syncing with a `RollingSync` strategy but it has switched to the default strategy, clean up the progressive sync application statuses
 			logCtx.Infof("Removing %v unnecessary AppStatus entries from ApplicationSet %v", len(applicationSetInfo.Status.ApplicationStatus), applicationSetInfo.Name)
 
 			err := r.setAppSetApplicationStatus(ctx, logCtx, &applicationSetInfo, []argov1alpha1.ApplicationSetApplicationStatus{})
 			if err != nil {
 				return ctrl.Result{}, fmt.Errorf("failed to clear previous AppSet application statuses for %v: %w", applicationSetInfo.Name, err)
 			}
-		} else if applicationSetInfo.Spec.Strategy != nil {
-			// appset uses progressive sync
+		} else if isRollingSyncStrategy(&applicationSetInfo) {
+			// The appset uses progressive sync with `RollingSync` strategy
 			for _, app := range currentApplications {
 				appMap[app.Name] = app
 			}
@@ -1008,8 +1008,14 @@ func appSyncEnabledForNextStep(appset *argov1alpha1.ApplicationSet, app argov1al
 	return true
 }
 
+func isRollingSyncStrategy(appset *argov1alpha1.ApplicationSet) bool {
+	// It's only RollingSync if the type specifically sets it
+	return appset.Spec.Strategy != nil && appset.Spec.Strategy.Type == "RollingSync" && appset.Spec.Strategy.RollingSync != nil
+}
+
 func progressiveSyncsRollingSyncStrategyEnabled(appset *argov1alpha1.ApplicationSet) bool {
-	return appset.Spec.Strategy != nil && appset.Spec.Strategy.RollingSync != nil && appset.Spec.Strategy.Type == "RollingSync" && len(appset.Spec.Strategy.RollingSync.Steps) > 0
+	// ProgressiveSync is enabled if the strategy is set to `RollingSync` + steps slice is not empty
+	return isRollingSyncStrategy(appset) && len(appset.Spec.Strategy.RollingSync.Steps) > 0
 }
 
 func isApplicationHealthy(app argov1alpha1.Application) bool {

applicationset/controllers/applicationset_controller_test.go

@@ -6736,3 +6736,62 @@ func TestIgnoreNotAllowedNamespaces(t *testing.T) {
 		})
 	}
 }
+
+func TestIsRollingSyncStrategy(t *testing.T) {
+	tests := []struct {
+		name     string
+		appset   *v1alpha1.ApplicationSet
+		expected bool
+	}{
+		{
+			name: "RollingSync strategy is explicitly set",
+			appset: &v1alpha1.ApplicationSet{
+				Spec: v1alpha1.ApplicationSetSpec{
+					Strategy: &v1alpha1.ApplicationSetStrategy{
+						Type: "RollingSync",
+						RollingSync: &v1alpha1.ApplicationSetRolloutStrategy{
+							Steps: []v1alpha1.ApplicationSetRolloutStep{},
+						},
+					},
+				},
+			},
+			expected: true,
+		},
+		{
+			name: "AllAtOnce strategy is explicitly set",
+			appset: &v1alpha1.ApplicationSet{
+				Spec: v1alpha1.ApplicationSetSpec{
+					Strategy: &v1alpha1.ApplicationSetStrategy{
+						Type: "AllAtOnce",
+					},
+				},
+			},
+			expected: false,
+		},
+		{
+			name: "Strategy is empty",
+			appset: &v1alpha1.ApplicationSet{
+				Spec: v1alpha1.ApplicationSetSpec{
+					Strategy: &v1alpha1.ApplicationSetStrategy{},
+				},
+			},
+			expected: false,
+		},
+		{
+			name: "Strategy is nil",
+			appset: &v1alpha1.ApplicationSet{
+				Spec: v1alpha1.ApplicationSetSpec{
+					Strategy: nil,
+				},
+			},
+			expected: false,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			result := isRollingSyncStrategy(tt.appset)
+			assert.Equal(t, tt.expected, result)
+		})
+	}
+}