Add support for empty expiration policies in pubsub (#783)

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

google-beta/resource_pubsub_subscription.go

@@ -183,7 +183,7 @@ func resourcePubsubSubscriptionCreate(d *schema.ResourceData, meta interface{})
 	expirationPolicyProp, err := expandPubsubSubscriptionExpirationPolicy(d.Get("expiration_policy"), d, config)
 	if err != nil {
 		return err
-	} else if v, ok := d.GetOkExists("expiration_policy"); !isEmptyValue(reflect.ValueOf(expirationPolicyProp)) && (ok || !reflect.DeepEqual(v, expirationPolicyProp)) {
+	} else if v, ok := d.GetOkExists("expiration_policy"); ok || !reflect.DeepEqual(v, expirationPolicyProp) {
 		obj["expirationPolicy"] = expirationPolicyProp
 	}
 
@@ -301,7 +301,7 @@ func resourcePubsubSubscriptionUpdate(d *schema.ResourceData, meta interface{})
 	expirationPolicyProp, err := expandPubsubSubscriptionExpirationPolicy(d.Get("expiration_policy"), d, config)
 	if err != nil {
 		return err
-	} else if v, ok := d.GetOkExists("expiration_policy"); !isEmptyValue(reflect.ValueOf(v)) && (ok || !reflect.DeepEqual(v, expirationPolicyProp)) {
+	} else if v, ok := d.GetOkExists("expiration_policy"); ok || !reflect.DeepEqual(v, expirationPolicyProp) {
 		obj["expirationPolicy"] = expirationPolicyProp
 	}
 
@@ -455,9 +455,6 @@ func flattenPubsubSubscriptionExpirationPolicy(v interface{}, d *schema.Resource
 		return nil
 	}
 	original := v.(map[string]interface{})
-	if len(original) == 0 {
-		return nil
-	}
 	transformed := make(map[string]interface{})
 	transformed["ttl"] =
 		flattenPubsubSubscriptionExpirationPolicyTtl(original["ttl"], d)
@@ -576,9 +573,14 @@ func expandPubsubSubscriptionRetainAckedMessages(v interface{}, d TerraformResou
 
 func expandPubsubSubscriptionExpirationPolicy(v interface{}, d TerraformResourceData, config *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{})
@@ -605,7 +607,9 @@ func resourcePubsubSubscriptionUpdateEncoder(d *schema.ResourceData, meta interf
 
 func resourcePubsubSubscriptionDecoder(d *schema.ResourceData, meta interface{}, res map[string]interface{}) (map[string]interface{}, error) {
 
+	// path is a derived field from the API-side `name`
 	path := fmt.Sprintf("projects/%s/subscriptions/%s", d.Get("project"), d.Get("name"))
 	d.Set("path", path)
+
 	return res, nil
 }

google-beta/resource_pubsub_subscription_test.go

@@ -8,6 +8,30 @@ import (
 	"github.com/hashicorp/terraform/helper/resource"
 )
 
+func TestAccPubsubSubscription_emptyTTL(t *testing.T) {
+	t.Parallel()
+
+	topic := fmt.Sprintf("tf-test-topic-%s", acctest.RandString(10))
+	subscription := fmt.Sprintf("projects/%s/subscriptions/tf-test-sub-%s", getTestProjectFromEnv(), acctest.RandString(10))
+
+	resource.Test(t, resource.TestCase{
+		PreCheck:     func() { testAccPreCheck(t) },
+		Providers:    testAccProviders,
+		CheckDestroy: testAccCheckPubsubSubscriptionDestroy,
+		Steps: []resource.TestStep{
+			{
+				Config: testAccPubsubSubscription_emptyTTL(topic, subscription),
+			},
+			{
+				ResourceName:      "google_pubsub_subscription.foo",
+				ImportStateId:     subscription,
+				ImportState:       true,
+				ImportStateVerify: true,
+			},
+		},
+	})
+}
+
 func TestAccPubsubSubscription_fullName(t *testing.T) {
 	t.Parallel()
 
@@ -81,6 +105,24 @@ func TestAccPubsubSubscription_update(t *testing.T) {
 	})
 }
 
+func testAccPubsubSubscription_emptyTTL(topic, subscription string) string {
+	return fmt.Sprintf(`
+resource "google_pubsub_topic" "foo" {
+	name = "%s"
+}
+
+resource "google_pubsub_subscription" "foo" {
+	name                 = "%s"
+	topic                = "${google_pubsub_topic.foo.id}"
+
+	message_retention_duration = "1200s"
+	retain_acked_messages = true
+	ack_deadline_seconds = 20
+	expiration_policy {}
+}
+`, topic, subscription)
+}
+
 // TODO: Add acceptance test for push delivery.
 //
 // Testing push endpoints is tricky for the following reason:
@@ -107,7 +149,8 @@ resource "google_pubsub_subscription" "foo" {
 		foo = "%s"
 	}
 	ack_deadline_seconds = %d
-}`, topic, subscription, label, deadline)
+}
+`, topic, subscription, label, deadline)
 }
 
 func TestGetComputedTopicName(t *testing.T) {