fix update to skip unchanged replicas

internal/services/appconfiguration/app_configuration_resource.go

@@ -480,6 +480,7 @@ func resourceAppConfigurationUpdate(d *pluginsdk.ResourceData, meta interface{})
 
 		// check if a replica has been removed from config and if so, delete it
 		deleteReplicaIds := make([]replicas.ReplicaId, 0)
+		unchangedReplicaNames := make(map[string]struct{}, 0)
 		oldReplicas, newReplicas := d.GetChange("replica")
 		for _, oldReplica := range oldReplicas.(*pluginsdk.Set).List() {
 			isRemoved := true
@@ -488,8 +489,8 @@ func resourceAppConfigurationUpdate(d *pluginsdk.ResourceData, meta interface{})
 			for _, newReplica := range newReplicas.(*pluginsdk.Set).List() {
 				newReplicaMap := newReplica.(map[string]interface{})
 
-				if strings.EqualFold(oldReplicaMap["name"].(string), newReplicaMap["name"].(string)) &&
-					strings.EqualFold(location.Normalize(oldReplicaMap["location"].(string)), location.Normalize(newReplicaMap["location"].(string))) {
+				if strings.EqualFold(oldReplicaMap["name"].(string), newReplicaMap["name"].(string)) && strings.EqualFold(location.Normalize(oldReplicaMap["location"].(string)), location.Normalize(newReplicaMap["location"].(string))) {
+					unchangedReplicaNames[oldReplicaMap["name"].(string)] = struct{}{}
 					isRemoved = false
 					break
 				}
@@ -511,6 +512,10 @@ func resourceAppConfigurationUpdate(d *pluginsdk.ResourceData, meta interface{})
 
 		// check if a replica has been added or an existing one changed its location, (re)create it
 		for _, replica := range *expandedReplicas {
+			if _, isUnchanged := unchangedReplicaNames[*replica.Name]; isUnchanged {
+				continue
+			}
+
 			replicaId := replicas.NewReplicaID(id.SubscriptionId, id.ResourceGroupName, id.ConfigurationStoreName, *replica.Name)
 
 			existingReplica, err := replicaClient.Get(ctx, replicaId)
@@ -778,8 +783,8 @@ func expandAppConfigurationReplicas(input []interface{}, configurationStoreName,
 
 	// check if there are duplicated replica names or locations
 	// location cannot be same as original configuration store and other replicas
-	locationSet := map[string]string{}
-	replicaNameSet := map[string]struct{}{}
+	locationSet := make(map[string]string, 0)
+	replicaNameSet := make(map[string]struct{}, 0)
 
 	for _, v := range input {
 		replica := v.(map[string]interface{})
@@ -794,9 +799,11 @@ func expandAppConfigurationReplicas(input []interface{}, configurationStoreName,
 		}
 		locationSet[replicaLocation] = replicaName
 
-		if _, ok := replicaNameSet[replicaName]; ok {
+		normalizedReplicaName := strings.ToLower(replicaName)
+		if _, ok := replicaNameSet[normalizedReplicaName]; ok {
 			return nil, fmt.Errorf("replica name %q is duplicated", replicaName)
 		}
+		replicaNameSet[normalizedReplicaName] = struct{}{}
 
 		if len(replicaName)+len(configurationStoreName) > 60 {
 			return nil, fmt.Errorf("replica name %q is too long, the total length of replica name and configuration store name should be greater than 60", replicaName)