Fix breaking change introduced in 0.46.0 - user_group_ids conflicts… (#184)

* Fix breaking chanke introduced in 0.46.0 - `user_group_ids` conflicts with `auth_token`

If you specify only `auth_token` - Terraform plan will fail because it interprets `user_group_ids = []` as specified value

* Auto Format

Co-authored-by: cloudpossebot <11232728+cloudpossebot@users.noreply.github.com>

Author: MaxymVlasov

README.md

@@ -315,7 +315,7 @@ Available targets:
 | <a name="input_tenant"></a> [tenant](#input\_tenant) | ID element \_(Rarely used, not included by default)\_. A customer identifier, indicating who this instance of a resource is for | `string` | `null` | no |
 | <a name="input_transit_encryption_enabled"></a> [transit\_encryption\_enabled](#input\_transit\_encryption\_enabled) | Set `true` to enable encryption in transit. Forced `true` if `var.auth_token` is set.<br>If this is enabled, use the [following guide](https://docs.aws.amazon.com/AmazonElastiCache/latest/red-ug/in-transit-encryption.html#connect-tls) to access redis. | `bool` | `true` | no |
 | <a name="input_use_existing_security_groups"></a> [use\_existing\_security\_groups](#input\_use\_existing\_security\_groups) | DEPRECATED: Use `create_security_group` instead.<br>Historical description: Flag to enable/disable creation of Security Group in the module.<br>Set to `true` to disable Security Group creation and provide a list of existing security Group IDs in `existing_security_groups` to place the cluster into.<br>Historical default: `false` | `bool` | `null` | no |
-| <a name="input_user_group_ids"></a> [user\_group\_ids](#input\_user\_group\_ids) | User Group ID to associate with the replication group | `list(string)` | `[]` | no |
+| <a name="input_user_group_ids"></a> [user\_group\_ids](#input\_user\_group\_ids) | User Group ID to associate with the replication group | `list(string)` | `null` | no |
 | <a name="input_vpc_id"></a> [vpc\_id](#input\_vpc\_id) | VPC ID | `string` | n/a | yes |
 | <a name="input_zone_id"></a> [zone\_id](#input\_zone\_id) | Route53 DNS Zone ID as list of string (0 or 1 items). If empty, no custom DNS name will be published.<br>If the list contains a single Zone ID, a custom DNS name will be pulished in that zone.<br>Can also be a plain string, but that use is DEPRECATED because of Terraform issues. | `any` | `[]` | no |
 

docs/terraform.md

@@ -105,7 +105,7 @@
 | <a name="input_tenant"></a> [tenant](#input\_tenant) | ID element \_(Rarely used, not included by default)\_. A customer identifier, indicating who this instance of a resource is for | `string` | `null` | no |
 | <a name="input_transit_encryption_enabled"></a> [transit\_encryption\_enabled](#input\_transit\_encryption\_enabled) | Set `true` to enable encryption in transit. Forced `true` if `var.auth_token` is set.<br>If this is enabled, use the [following guide](https://docs.aws.amazon.com/AmazonElastiCache/latest/red-ug/in-transit-encryption.html#connect-tls) to access redis. | `bool` | `true` | no |
 | <a name="input_use_existing_security_groups"></a> [use\_existing\_security\_groups](#input\_use\_existing\_security\_groups) | DEPRECATED: Use `create_security_group` instead.<br>Historical description: Flag to enable/disable creation of Security Group in the module.<br>Set to `true` to disable Security Group creation and provide a list of existing security Group IDs in `existing_security_groups` to place the cluster into.<br>Historical default: `false` | `bool` | `null` | no |
-| <a name="input_user_group_ids"></a> [user\_group\_ids](#input\_user\_group\_ids) | User Group ID to associate with the replication group | `list(string)` | `[]` | no |
+| <a name="input_user_group_ids"></a> [user\_group\_ids](#input\_user\_group\_ids) | User Group ID to associate with the replication group | `list(string)` | `null` | no |
 | <a name="input_vpc_id"></a> [vpc\_id](#input\_vpc\_id) | VPC ID | `string` | n/a | yes |
 | <a name="input_zone_id"></a> [zone\_id](#input\_zone\_id) | Route53 DNS Zone ID as list of string (0 or 1 items). If empty, no custom DNS name will be published.<br>If the list contains a single Zone ID, a custom DNS name will be pulished in that zone.<br>Can also be a plain string, but that use is DEPRECATED because of Terraform issues. | `any` | `[]` | no |
 

variables.tf

@@ -245,7 +245,7 @@ variable "description" {
 
 variable "user_group_ids" {
   type        = list(string)
-  default     = []
+  default     = null
   description = "User Group ID to associate with the replication group"
 }