chore: Avoids non-empty plan after removing advanced_configuration block removal (#3134)

* show failing test

* fix: optional-only problem in advanced_configuration

* not safe to use state for custom_openssl_cipher_config_tls12 when `tls_cipher_config_mode` is changed

* remove: unnecessary null value, can rely on API empty list

* address PR comments

* chore: update comment

* doc: Add more comments to clarify behavior

Author: EspenAlbert

internal/service/advancedcluster/resource_advanced_cluster_test.go

@@ -1271,6 +1271,10 @@ func TestAccMockableAdvancedCluster_replicasetAdvConfigUpdate(t *testing.T) {
 				Config: configBasicReplicaset(t, projectID, clusterName, fullUpdate),
 				Check:  checksUpdate,
 			},
+			{
+				Config: configBasicReplicaset(t, projectID, clusterName, ""),
+				Check:  checks,
+			},
 			acc.TestStepImportCluster(resourceName),
 		},
 	})

internal/service/advancedcluster/testdata/TestAccMockableAdvancedCluster_replicasetAdvConfigUpdate.yaml

@@ -51,17 +51,16 @@ func AddAdvancedConfig(ctx context.Context, tfModel *TFModel, input *admin.Clust
 		}
 	}
 
-	advancedConfig.CustomOpensslCipherConfigTls12 = customOpensslCipherConfigTLS12(ctx, diags, input) // required to handle move state
+	advancedConfig.CustomOpensslCipherConfigTls12 = customOpensslCipherConfigTLS12(ctx, diags, input)
 	objType, diagsLocal := types.ObjectValueFrom(ctx, AdvancedConfigurationObjType.AttrTypes, advancedConfig)
 	diags.Append(diagsLocal...)
 	tfModel.AdvancedConfiguration = objType
 }
 
 func customOpensslCipherConfigTLS12(ctx context.Context, diags *diag.Diagnostics, processArgs *admin.ClusterDescriptionProcessArgs20240805) types.Set {
-	if processArgs == nil || len(*processArgs.CustomOpensslCipherConfigTls12) == 0 {
+	if processArgs == nil {
 		return types.SetNull(types.StringType)
 	}
-
 	customOpensslCipherConfigTLS12, d := types.SetValueFrom(ctx, types.StringType, processArgs.CustomOpensslCipherConfigTls12)
 	diags.Append(d...)
 	return customOpensslCipherConfigTLS12

internal/service/advancedclustertpf/model_ClusterDescriptionProcessArgs20240805.go

@@ -22,8 +22,13 @@ func NewAtlasReqAdvancedConfiguration(ctx context.Context, objInput *types.Objec
 		diags.Append(localDiags...)
 		return resp
 	}
+	changeStreamOptionsPreAndPostImagesExpireAfterSeconds := conversion.NilForUnknown(input.ChangeStreamOptionsPreAndPostImagesExpireAfterSeconds, conversion.Int64PtrToIntPtr(input.ChangeStreamOptionsPreAndPostImagesExpireAfterSeconds.ValueInt64Pointer()))
+	if changeStreamOptionsPreAndPostImagesExpireAfterSeconds == nil {
+		// in case the user removes the value, we should set it to -1, a special value used by the backend to use its default behavior
+		changeStreamOptionsPreAndPostImagesExpireAfterSeconds = conversion.Pointer(-1)
+	}
 	return &admin.ClusterDescriptionProcessArgs20240805{
-		ChangeStreamOptionsPreAndPostImagesExpireAfterSeconds: conversion.NilForUnknown(input.ChangeStreamOptionsPreAndPostImagesExpireAfterSeconds, conversion.Int64PtrToIntPtr(input.ChangeStreamOptionsPreAndPostImagesExpireAfterSeconds.ValueInt64Pointer())),
+		ChangeStreamOptionsPreAndPostImagesExpireAfterSeconds: changeStreamOptionsPreAndPostImagesExpireAfterSeconds,
 		DefaultWriteConcern:              conversion.NilForUnknown(input.DefaultWriteConcern, input.DefaultWriteConcern.ValueStringPointer()),
 		JavascriptEnabled:                conversion.NilForUnknown(input.JavascriptEnabled, input.JavascriptEnabled.ValueBoolPointer()),
 		MinimumEnabledTlsProtocol:        conversion.NilForUnknown(input.MinimumEnabledTlsProtocol, input.MinimumEnabledTlsProtocol.ValueStringPointer()),

internal/service/advancedclustertpf/model_to_ClusterDescriptionProcessArgs20240805.go

@@ -13,10 +13,12 @@ import (
 )
 
 var (
+	// Change mappings uses `attribute_name`, it doesn't care about the nested level.
 	attributeRootChangeMapping = map[string][]string{
 		"disk_size_gb":           {}, // disk_size_gb can be change at any level/spec
 		"replication_specs":      {},
 		"mongo_db_major_version": {"mongo_db_version"},
+		"tls_cipher_config_mode": {"custom_openssl_cipher_config_tls12"},
 	}
 	attributeReplicationSpecChangeMapping = map[string][]string{
 		// All these fields can exist in specs that are computed, therefore, it is not safe to use them when they have changed.

internal/service/advancedclustertpf/plan_modifier.go

@@ -440,12 +440,14 @@ func AdvancedConfigurationSchema(ctx context.Context) schema.SingleNestedAttribu
 		Computed:            true,
 		Optional:            true,
 		MarkdownDescription: "advanced_configuration", // TODO: add description
+		// Avoid adding optional-only attributes, if the block is removed and attributes are not null in the state we get unintentional plan changes after apply.
+		// Avoid computed-optional with Default, if the block is removed and the attribute Default != state value we get unintentional plan changes after apply.
 		Attributes: map[string]schema.Attribute{
 			"change_stream_options_pre_and_post_images_expire_after_seconds": schema.Int64Attribute{
-				Optional:            true,
+				Optional: true,
+				// Default set in NewAtlasReqAdvancedConfiguration
 				Computed:            true,
 				MarkdownDescription: "The minimum pre- and post-image retention time in seconds.",
-				Default:             int64default.StaticInt64(-1), // in case the user removes the value, we should set it to -1, a special value used by the backend to use its default behavior
 				PlanModifiers: []planmodifier.Int64{
 					PlanMustUseMongoDBVersion(7.0, EqualOrHigher),
 				},
@@ -512,13 +514,15 @@ func AdvancedConfigurationSchema(ctx context.Context) schema.SingleNestedAttribu
 				MarkdownDescription: "fail_index_key_too_long", // TODO: add description
 			},
 			"default_max_time_ms": schema.Int64Attribute{
+				Computed:            true,
 				Optional:            true,
 				MarkdownDescription: "Default time limit in milliseconds for individual read operations to complete. This parameter is supported only for MongoDB version 8.0 and above.",
 				PlanModifiers: []planmodifier.Int64{
 					PlanMustUseMongoDBVersion(8.0, EqualOrHigher),
 				},
 			},
 			"custom_openssl_cipher_config_tls12": schema.SetAttribute{
+				Computed:            true,
 				Optional:            true,
 				ElementType:         types.StringType,
 				MarkdownDescription: "The custom OpenSSL cipher suite list for TLS 1.2. This field is only valid when `tls_cipher_config_mode` is set to `CUSTOM`.",