fix: Fixes tags in mongodbatlas_flex_cluster (#2829)

* fix tags

* add tests

* fix

Author: oarbusi

internal/common/conversion/tags.go

@@ -31,3 +31,7 @@ func NewTFTags(tags []admin.ResourceTag) types.Map {
 	}
 	return types.MapValueMust(types.StringType, typesTags)
 }
+
+func UseNilForEmpty(planTag, newTag types.Map) bool {
+	return planTag.IsNull() && len(newTag.Elements()) == 0
+}

internal/service/flexcluster/resource.go

@@ -8,6 +8,7 @@ import (
 
 	"github.com/hashicorp/terraform-plugin-framework/path"
 	"github.com/hashicorp/terraform-plugin-framework/resource"
+	"github.com/hashicorp/terraform-plugin-framework/types"
 	"go.mongodb.org/atlas-sdk/v20241113001/admin"
 
 	"github.com/mongodb/terraform-provider-mongodbatlas/internal/common/conversion"
@@ -77,6 +78,11 @@ func (r *rs) Create(ctx context.Context, req resource.CreateRequest, resp *resou
 		resp.Diagnostics.Append(diags...)
 		return
 	}
+
+	if conversion.UseNilForEmpty(tfModel.Tags, newFlexClusterModel.Tags) {
+		newFlexClusterModel.Tags = types.MapNull(types.StringType)
+	}
+
 	resp.Diagnostics.Append(resp.State.Set(ctx, newFlexClusterModel)...)
 }
 
@@ -103,6 +109,11 @@ func (r *rs) Read(ctx context.Context, req resource.ReadRequest, resp *resource.
 		resp.Diagnostics.Append(diags...)
 		return
 	}
+
+	if conversion.UseNilForEmpty(flexClusterState.Tags, newFlexClusterModel.Tags) {
+		newFlexClusterModel.Tags = types.MapNull(types.StringType)
+	}
+
 	resp.Diagnostics.Append(resp.State.Set(ctx, newFlexClusterModel)...)
 }
 
@@ -145,6 +156,11 @@ func (r *rs) Update(ctx context.Context, req resource.UpdateRequest, resp *resou
 		resp.Diagnostics.Append(diags...)
 		return
 	}
+
+	if conversion.UseNilForEmpty(plan.Tags, newFlexClusterModel.Tags) {
+		newFlexClusterModel.Tags = types.MapNull(types.StringType)
+	}
+
 	resp.Diagnostics.Append(resp.State.Set(ctx, newFlexClusterModel)...)
 }
 

internal/service/flexcluster/resource_test.go

@@ -44,15 +44,15 @@ func basicTestCase(t *testing.T) *resource.TestCase {
 		CheckDestroy:             checkDestroy,
 		Steps: []resource.TestStep{
 			{
-				Config: configBasic(projectID, clusterName, provider, region, true),
-				Check:  checksFlexCluster(projectID, clusterName, true),
+				Config: configBasic(projectID, clusterName, provider, region, true, false),
+				Check:  checksFlexCluster(projectID, clusterName, true, false),
 			},
 			{
-				Config: configBasic(projectID, clusterName, provider, region, false),
-				Check:  checksFlexCluster(projectID, clusterName, false),
+				Config: configBasic(projectID, clusterName, provider, region, false, true),
+				Check:  checksFlexCluster(projectID, clusterName, false, true),
 			},
 			{
-				Config:            configBasic(projectID, clusterName, provider, region, true),
+				Config:            configBasic(projectID, clusterName, provider, region, true, true),
 				ResourceName:      resourceName,
 				ImportStateIdFunc: importStateIDFunc(resourceName),
 				ImportState:       true,
@@ -80,30 +80,37 @@ func failedUpdateTestCase(t *testing.T) *resource.TestCase {
 		CheckDestroy:             checkDestroy,
 		Steps: []resource.TestStep{
 			{
-				Config: configBasic(projectID, clusterName, provider, region, false),
-				Check:  checksFlexCluster(projectID, clusterName, false),
+				Config: configBasic(projectID, clusterName, provider, region, false, false),
+				Check:  checksFlexCluster(projectID, clusterName, false, false),
 			},
 			{
-				Config:      configBasic(projectID, clusterNameUpdated, provider, region, false),
+				Config:      configBasic(projectID, clusterNameUpdated, provider, region, false, false),
 				ExpectError: regexp.MustCompile("name cannot be updated"),
 			},
 			{
-				Config:      configBasic(projectIDUpdated, clusterName, provider, region, false),
+				Config:      configBasic(projectIDUpdated, clusterName, provider, region, false, false),
 				ExpectError: regexp.MustCompile("project_id cannot be updated"),
 			},
 			{
-				Config:      configBasic(projectID, clusterName, providerUpdated, region, false),
+				Config:      configBasic(projectID, clusterName, providerUpdated, region, false, false),
 				ExpectError: regexp.MustCompile("provider_settings.backing_provider_name cannot be updated"),
 			},
 			{
-				Config:      configBasic(projectID, clusterName, provider, regionUpdated, false),
+				Config:      configBasic(projectID, clusterName, provider, regionUpdated, false, false),
 				ExpectError: regexp.MustCompile("provider_settings.region_name cannot be updated"),
 			},
 		},
 	}
 }
 
-func configBasic(projectID, clusterName, provider, region string, terminationProtectionEnabled bool) string {
+func configBasic(projectID, clusterName, provider, region string, terminationProtectionEnabled, tags bool) string {
+	tagsConfig := ""
+	if tags {
+		tagsConfig = `
+			tags = {
+				testKey = "testValue"
+			}`
+	}
 	return fmt.Sprintf(`
 		resource "mongodbatlas_flex_cluster" "test" {
 			project_id = %[1]q
@@ -113,26 +120,26 @@ func configBasic(projectID, clusterName, provider, region string, terminationPro
 				region_name           = %[4]q
 			}
 			termination_protection_enabled = %[5]t
-			tags = {
-				testKey = "testValue"
-			}
+			%[6]s
 		}
 		data "mongodbatlas_flex_cluster" "test" {
 			project_id = mongodbatlas_flex_cluster.test.project_id
 			name       = mongodbatlas_flex_cluster.test.name
 		}
 		data "mongodbatlas_flex_clusters" "test" {
 			project_id = mongodbatlas_flex_cluster.test.project_id
-		}`, projectID, clusterName, provider, region, terminationProtectionEnabled)
+		}`, projectID, clusterName, provider, region, terminationProtectionEnabled, tagsConfig)
 }
 
-func checksFlexCluster(projectID, clusterName string, terminationProtectionEnabled bool) resource.TestCheckFunc {
+func checksFlexCluster(projectID, clusterName string, terminationProtectionEnabled, tagsCheck bool) resource.TestCheckFunc {
 	checks := []resource.TestCheckFunc{checkExists()}
 	attrMap := map[string]string{
 		"project_id":                     projectID,
 		"name":                           clusterName,
 		"termination_protection_enabled": fmt.Sprintf("%v", terminationProtectionEnabled),
-		"tags.testKey":                   "testValue",
+	}
+	if tagsCheck {
+		attrMap["tags.testKey"] = "testValue"
 	}
 	pluralMap := map[string]string{
 		"project_id": projectID,