From 36c40b1e67e8ff8c76be2f37b38534fcfc6c1649 Mon Sep 17 00:00:00 2001
From: Guillaume Viguier-Just <guillaume.viguier-just@propulse-lab.com>
Date: Fri, 27 Dec 2019 11:59:21 +0100
Subject: [PATCH] #136 - Fixed issue with eventSourceArn if not a resource
 reference

---
 lib/stackops/events.js | 50 ++++++++++++++++++++++--------------------
 1 file changed, 26 insertions(+), 24 deletions(-)

diff --git a/lib/stackops/events.js b/lib/stackops/events.js
index a528271..6d67704 100644
--- a/lib/stackops/events.js
+++ b/lib/stackops/events.js
@@ -32,31 +32,33 @@ module.exports = function(currentTemplate, aliasStackTemplates, currentAliasStac
 
 		// Make sure that the referenced resource is exported by the stageStack.
 		const resourceRef = utils.findAllReferences(_.get(subscription, 'Properties.EventSourceArn'));
-		// Build the export name
-		let resourceRefName = _.get(resourceRef, '[0].ref');
-		if (_.has(subscription.Properties, 'EventSourceArn.Fn::GetAtt')) {
-			const attribute = subscription.Properties.EventSourceArn['Fn::GetAtt'][1];
-			resourceRefName += attribute;
-		}
-		// Add the ref output to the stack if not already done.
-		stageStack.Outputs[resourceRefName] = {
-			Description: 'Alias resource reference',
-			Value: subscription.Properties.EventSourceArn,
-			Export: {
-				Name: `${stackName}-${resourceRefName}`
-			}
-		};
-		// Add the output to the referenced alias outputs
-		const aliasOutputs = JSON.parse(aliasStack.Outputs.AliasOutputs.Value);
-		aliasOutputs.push(resourceRefName);
-		aliasStack.Outputs.AliasOutputs.Value = JSON.stringify(aliasOutputs);
-		// Replace the reference with the cross stack reference
-		subscription.Properties.EventSourceArn = {};
+		if (resourceRef.length > 0) {
+		  // Build the export name
+		  let resourceRefName = _.get(resourceRef, '[0].ref');
+		  if (_.has(subscription.Properties, 'EventSourceArn.Fn::GetAtt')) {
+			  const attribute = subscription.Properties.EventSourceArn['Fn::GetAtt'][1];
+			  resourceRefName += attribute;
+		  }
+		  // Add the ref output to the stack if not already done.
+		  stageStack.Outputs[resourceRefName] = {
+			  Description: 'Alias resource reference',
+			  Value: subscription.Properties.EventSourceArn,
+			  Export: {
+				  Name: `${stackName}-${resourceRefName}`
+			 }
+		  };
+		  // Add the output to the referenced alias outputs
+		  const aliasOutputs = JSON.parse(aliasStack.Outputs.AliasOutputs.Value);
+		  aliasOutputs.push(resourceRefName);
+		  aliasStack.Outputs.AliasOutputs.Value = JSON.stringify(aliasOutputs);
+		  // Replace the reference with the cross stack reference
+		  subscription.Properties.EventSourceArn = {};
 
-		// Event source ARNs can be volatile - e.g. DynamoDB and must not be referenced
-		// with Fn::ImportValue which does not allow for changes. So we have to register
-		// them for delayed lookup until the base stack has been updated.
-		this.addDeferredOutput(`${stackName}-${resourceRefName}`, subscription.Properties, 'EventSourceArn');
+		  // Event source ARNs can be volatile - e.g. DynamoDB and must not be referenced
+		  // with Fn::ImportValue which does not allow for changes. So we have to register
+		  // them for delayed lookup until the base stack has been updated.
+		  this.addDeferredOutput(`${stackName}-${resourceRefName}`, subscription.Properties, 'EventSourceArn');
+		}
 
 		// Remove mapping from stage stack
 		delete stageStack.Resources[name];