Fix bug in Pub/Sub Subscription avroConfig which was not sending empty configurations. (#12108) (#20365)

[upstream:e5c4adb8ea7a58fcdb6a61b800c0e07b022934fa]

Signed-off-by: Modular Magician <[email protected]>

Author: modular-magician

.changelog/12108.txt

@@ -0,0 +1,3 @@
+```release-note:bug
+pubsub: fixed the issue to allow successfully configure empty `cloud_storage_config.avro_config` field in `google_pubsub_subscription`
+```

google/services/pubsub/resource_pubsub_subscription.go

@@ -1261,9 +1261,6 @@ func flattenPubsubSubscriptionCloudStorageConfigAvroConfig(v interface{}, d *sch
 		return nil
 	}
 	original := v.(map[string]interface{})
-	if len(original) == 0 {
-		return nil
-	}
 	transformed := make(map[string]interface{})
 	transformed["write_metadata"] =
 		flattenPubsubSubscriptionCloudStorageConfigAvroConfigWriteMetadata(original["writeMetadata"], d, config)
@@ -1648,7 +1645,7 @@ func expandPubsubSubscriptionCloudStorageConfig(v interface{}, d tpgresource.Ter
 	transformedAvroConfig, err := expandPubsubSubscriptionCloudStorageConfigAvroConfig(original["avro_config"], d, config)
 	if err != nil {
 		return nil, err
-	} else if val := reflect.ValueOf(transformedAvroConfig); val.IsValid() && !tpgresource.IsEmptyValue(val) {
+	} else {
 		transformed["avroConfig"] = transformedAvroConfig
 	}
 
@@ -1696,24 +1693,29 @@ func expandPubsubSubscriptionCloudStorageConfigState(v interface{}, d tpgresourc
 
 func expandPubsubSubscriptionCloudStorageConfigAvroConfig(v interface{}, d tpgresource.TerraformResourceData, config *transport_tpg.Config) (interface{}, error) {
 	l := v.([]interface{})
-	if len(l) == 0 || l[0] == nil {
+	if len(l) == 0 {
 		return nil, nil
 	}
+
+	if l[0] == nil {
+		transformed := make(map[string]interface{})
+		return transformed, nil
+	}
 	raw := l[0]
 	original := raw.(map[string]interface{})
 	transformed := make(map[string]interface{})
 
 	transformedWriteMetadata, err := expandPubsubSubscriptionCloudStorageConfigAvroConfigWriteMetadata(original["write_metadata"], d, config)
 	if err != nil {
 		return nil, err
-	} else if val := reflect.ValueOf(transformedWriteMetadata); val.IsValid() && !tpgresource.IsEmptyValue(val) {
+	} else {
 		transformed["writeMetadata"] = transformedWriteMetadata
 	}
 
 	transformedUseTopicSchema, err := expandPubsubSubscriptionCloudStorageConfigAvroConfigUseTopicSchema(original["use_topic_schema"], d, config)
 	if err != nil {
 		return nil, err
-	} else if val := reflect.ValueOf(transformedUseTopicSchema); val.IsValid() && !tpgresource.IsEmptyValue(val) {
+	} else {
 		transformed["useTopicSchema"] = transformedUseTopicSchema
 	}
 

google/services/pubsub/resource_pubsub_subscription_test.go

@@ -354,6 +354,31 @@ func TestAccPubsubSubscriptionCloudStorage_updateAvro(t *testing.T) {
 	})
 }
 
+func TestAccPubsubSubscriptionCloudStorage_emptyAvroConfig(t *testing.T) {
+	t.Parallel()
+
+	bucket := fmt.Sprintf("tf-test-bucket-%s", acctest.RandString(t, 10))
+	topic := fmt.Sprintf("tf-test-topic-%s", acctest.RandString(t, 10))
+	subscriptionShort := fmt.Sprintf("tf-test-sub-%s", acctest.RandString(t, 10))
+
+	acctest.VcrTest(t, resource.TestCase{
+		PreCheck:                 func() { acctest.AccTestPreCheck(t) },
+		ProtoV5ProviderFactories: acctest.ProtoV5ProviderFactories(t),
+		CheckDestroy:             testAccCheckPubsubSubscriptionDestroyProducer(t),
+		Steps: []resource.TestStep{
+			{
+				Config: testAccPubsubSubscriptionCloudStorage_basic(bucket, topic, subscriptionShort, "pre-", "-suffix", "YYYY-MM-DD/hh_mm_ssZ", 1000, "300s", 1000, "", "empty-avro"),
+			},
+			{
+				ResourceName:      "google_pubsub_subscription.foo",
+				ImportStateId:     subscriptionShort,
+				ImportState:       true,
+				ImportStateVerify: true,
+			},
+		},
+	})
+}
+
 func TestAccPubsubSubscriptionCloudStorage_serviceAccount(t *testing.T) {
 	t.Parallel()
 
@@ -825,6 +850,8 @@ resource "google_storage_bucket_iam_member" "admin" {
     use_topic_schema = true
   }
 `
+	} else if outputFormat == "empty-avro" {
+		outputFormatString = `avro_config {}`
 	}
 	return fmt.Sprintf(`
 data "google_project" "project" { }