Add MessageTransform field to 'google_pubsub_subscription'

mmv1/products/pubsub/Subscription.yaml

@@ -506,3 +506,63 @@ properties:
 
       Note that subscribers may still receive multiple copies of a message when `enable_exactly_once_delivery`
       is true if the message was published multiple times by a publisher client. These copies are considered distinct by Pub/Sub and have distinct messageId values
+  - name: messageTransforms
+    type: Array
+    required: false
+    description: |
+      Transforms to be applied to messages published to the topic. Transforms are applied in the
+      order specified.
+    item_type:
+      type: NestedObject
+      properties:
+        - name: javascriptUdf
+          type: NestedObject
+          required: false
+          description: |
+            Javascript User Defined Function. If multiple Javascript UDFs are specified on a resource,
+            each one must have a unique `function_name`.
+          properties:
+            - name: functionName
+              type: String
+              required: true
+              description: |
+                Name of the JavaScript function that should be applied to Pub/Sub messages.
+            - name: code
+              type: String
+              required: true
+              description: |
+                JavaScript code that contains a function `function_name` with the
+                following signature:
+                ```
+                  /**
+                  * Transforms a Pub/Sub message.
+                  *
+                  * @return {(Object<string, (string | Object<string, string>)>|null)} - To
+                  * filter a message, return `null`. To transform a message return a map
+                  * with the following keys:
+                  *   - (required) 'data' : {string}
+                  *   - (optional) 'attributes' : {Object<string, string>}
+                  * Returning empty `attributes` will remove all attributes from the
+                  * message.
+                  *
+                  * @param  {(Object<string, (string | Object<string, string>)>} Pub/Sub
+                  * message. Keys:
+                  *   - (required) 'data' : {string}
+                  *   - (required) 'attributes' : {Object<string, string>}
+                  *
+                  * @param  {Object<string, any>} metadata - Pub/Sub message metadata.
+                  * Keys:
+                  *   - (required) 'message_id'  : {string}
+                  *   - (optional) 'publish_time': {string} YYYY-MM-DDTHH:MM:SSZ format
+                  *   - (optional) 'ordering_key': {string}
+                  */
+                  function <function_name>(message, metadata) {
+                  }
+                ```
+        - name: enabled
+          type: Boolean
+          required: false
+          default_value: true
+          description: |
+            If set to `true`, the transform is enabled. If `false` the transform is disabled and will
+            not be applied to messages. Default: `true`.

mmv1/templates/terraform/examples/pubsub_subscription_javascript_udf.tf.tmpl

@@ -0,0 +1,18 @@
+resource "google_pubsub_topic" "{{$.PrimaryResourceId}}" {
+  name = "{{index $.Vars "topic_name"}}"
+}
+
+resource "google_pubsub_subscription" "{{$.PrimaryResourceId}}" {
+  name  = "{{index $.Vars "subscription_name"}}"
+  topic = google_pubsub_topic.{{$.PrimaryResourceId}}.id
+
+  message_transforms = [
+    {
+      javascript_udf {
+        function_name = "filter_falsy",
+        code = "function filter_falsy(message, metadata) {\n  return message ? message : null;\n}\n"
+      }
+      enabled = true
+    }
+  ]
+}

mmv1/third_party/terraform/services/pubsub/resource_pubsub_subscription_test.go

@@ -539,6 +539,54 @@ func TestAccPubsubSubscription_filter(t *testing.T) {
 	})
 }
 
+func TestAccPubsubSubscription_javascriptUdfUpdate(t *testing.T) {
+	t.Parallel()
+
+	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: testAccPubsubSubscription_updateWithUpdatedJavascriptUdfSettings(topic, subscriptionShort),
+			},
+			{
+				ResourceName:      "google_pubsub_subscription.foo",
+				ImportStateId: subscriptionShort,
+				ImportState:       true,
+				ImportStateVerify: true,
+			},
+		},
+	})
+}
+
+func testAccPubsubSubscription_updateWithUpdatedJavascriptUdfSettings(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
+	name = "%s"
+	message_transforms = [
+		{
+			javascript_udf {
+				function_name = "filter_falsy",
+				code = "function filter_falsy(message, metadata) {\n  return message ? message : null;\n}\n"
+			}
+			enabled = true
+		}
+	]
+}
+`, topic, subscription)
+}
+
+
 func testAccPubsubSubscription_emptyTTL(topic, subscription string) string {
 	return fmt.Sprintf(`
 resource "google_pubsub_topic" "foo" {