fix(custom-resources): physical resource id must be determined before isComplete

packages/@aws-cdk/custom-resources/lib/provider-framework/runtime/framework.ts

@@ -73,6 +73,7 @@ async function isComplete(event: AWSCDKAsyncCustomResource.IsCompleteRequest) {
 
   const response = {
     ...event,
+    ...isCompleteResult,
     Data: {
       ...event.Data,
       ...isCompleteResult.Data,

packages/@aws-cdk/custom-resources/lib/provider-framework/types.d.ts

@@ -4,7 +4,7 @@
 /**
  * these types can be accessed without needing to `import` the module.
  * e.g. `AWSCDKAsyncCustomResource.OnEventRequest`
- */ 
+ */
 export as namespace AWSCDKAsyncCustomResource;
 
 /**
@@ -105,6 +105,11 @@ export interface IsCompleteResponse {
    */
   readonly IsComplete: boolean;
 
+  /**
+   * If present, overrides the PhysicalResourceId of OnEventResponse with the PhysicalResourceId of IsCompleteResponse.
+   */
+  readonly PhysicalResourceId?: string;
+
   /**
    * Additional/changes to resource attributes. This hash will be merged with the one returned from `OnEventResponse`.
    */

packages/@aws-cdk/custom-resources/test/provider-framework/runtime.test.ts

@@ -169,6 +169,23 @@ describe('PhysicalResourceId', () => {
     });
   });
 
+  test('UPDATE: can override the physical ID with the actual on isComplete', async () => {
+    // GIVEN
+    mocks.onEventImplMock = async () => ({ PhysicalResourceId: 'TemporaryPhysicalId' });
+    mocks.isCompleteImplMock = async () => ({ IsComplete: true, PhysicalResourceId: 'NewPhysicalId' });
+
+    // WHEN
+    await simulateEvent({
+      RequestType: 'Update',
+      PhysicalResourceId: 'CurrentPhysicalId',
+    });
+
+    // THEN
+    expectCloudFormationSuccess({
+      PhysicalResourceId: 'NewPhysicalId',
+    });
+  });
+
   test('DELETE: cannot change the physical resource ID during a delete', async () => {
     // GIVEN
     mocks.onEventImplMock = async () => ({ PhysicalResourceId: 'NewPhysicalId' });