fix(cli): direct deploy method fails when there are no updates (#28523)

This is correctly handled for empty change sets here:

https://github.com/aws/aws-cdk/blob/9d8b06f6478a98e01e3aaa86c1dbf22d6e861f05/packages/aws-cdk/lib/api/util/cloudformation.ts#L290-L296

but not for direct updates.

----

*By submitting this pull request, I confirm that my contribution is made under the terms of the Apache-2.0 license*

packages/aws-cdk/lib/api/deploy-stack.ts

@@ -478,16 +478,24 @@ class FullCloudFormationDeployment {
     const startTime = new Date();
 
     if (this.update) {
-      await this.cfn.updateStack({
-        StackName: this.stackName,
-        ClientRequestToken: `update${this.uuid}`,
-        ...this.commonPrepareOptions(),
-        ...this.commonExecuteOptions(),
-      }).promise();
-
-      const ret = await this.monitorDeployment(startTime, undefined);
       await this.updateTerminationProtection();
-      return ret;
+
+      try {
+        await this.cfn.updateStack({
+          StackName: this.stackName,
+          ClientRequestToken: `update${this.uuid}`,
+          ...this.commonPrepareOptions(),
+          ...this.commonExecuteOptions(),
+        }).promise();
+      } catch (err: any) {
+        if (err.message === 'No updates are to be performed.') {
+          debug('No updates are to be performed for stack %s', this.stackName);
+          return { noOp: true, outputs: this.cloudFormationStack.outputs, stackArn: this.cloudFormationStack.stackId };
+        }
+        throw err;
+      }
+
+      return this.monitorDeployment(startTime, undefined);
     } else {
       // Take advantage of the fact that we can set termination protection during create
       const terminationProtection = this.stackArtifact.terminationProtection ?? false;

packages/aws-cdk/test/api/deploy-stack.test.ts

@@ -206,6 +206,25 @@ test('call UpdateStack when method=direct and the stack exists already', async (
   expect(cfnMocks.updateStack).toHaveBeenCalled();
 });
 
+test('method=direct and no updates to be performed', async () => {
+  cfnMocks.updateStack?.mockRejectedValueOnce({
+    code: 'ValidationError',
+    message: 'No updates are to be performed.',
+  } as never);
+
+  // WHEN
+  givenStackExists();
+
+  const ret = await deployStack({
+    ...standardDeployStackArguments(),
+    deploymentMethod: { method: 'direct' },
+    force: true,
+  });
+
+  // THEN
+  expect(ret).toEqual(expect.objectContaining({ noOp: true }));
+});
+
 test("does not call tryHotswapDeployment() if 'hotswap' is false", async () => {
   // WHEN
   await deployStack({