Provide stackId in ResourceHandlerRequest (#314)

* Provide stackId in ResourceHandlerRequest

Author: omkhegde

src/main/java/software/amazon/cloudformation/LambdaWrapper.java

@@ -272,6 +272,7 @@ public void handleRequest(final InputStream inputStream, final OutputStream outp
 
         if (resourceHandlerRequest != null) {
             resourceHandlerRequest.setPreviousResourceTags(getPreviousResourceTags(request));
+            resourceHandlerRequest.setStackId(getStackId(request));
         }
 
         this.metricsPublisherProxy.publishInvocationMetric(Instant.now(), request.getAction());
@@ -570,6 +571,15 @@ protected Map<String, String> getPreviousResourceTags(final HandlerRequest<Resou
         return previousResourceTags;
     }
 
+    @VisibleForTesting
+    protected String getStackId(final HandlerRequest<ResourceT, CallbackT> request) {
+        if (request != null) {
+            return request.getStackId();
+        }
+
+        return null;
+    }
+
     private void replaceInMap(final Map<String, String> targetMap, final Map<String, String> sourceMap) {
         if (targetMap == null) {
             return;

src/main/java/software/amazon/cloudformation/proxy/ResourceHandlerRequest.java

@@ -43,4 +43,5 @@ public class ResourceHandlerRequest<T> {
     private String logicalResourceIdentifier;
     private String nextToken;
     private String region;
+    private String stackId;
 }

src/test/java/software/amazon/cloudformation/LambdaWrapperTest.java

@@ -1078,4 +1078,14 @@ public void getPreviousResourceTags_resourceTagOverridesStackTag() {
         assertThat(tags.size()).isEqualTo(1);
         assertThat(tags.get("Tag1")).isEqualTo("Value2");
     }
+
+    @Test
+    public void getStackId_setAndGetStackId() {
+        final HandlerRequest<TestModel, TestContext> request = new HandlerRequest<>();
+        request.setStackId("AWSStackId");
+
+        final String stackId = wrapper.getStackId(request);
+        assertThat(stackId).isNotNull();
+        assertThat(stackId).isEqualTo("AWSStackId");
+    }
 }