fix(cli): state machine hotswap fails if the DependsOn change (aws#…

…22396)

----
*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/hotswap/stepfunctions-state-machines.ts

@@ -37,6 +37,10 @@ async function isStateMachineDefinitionOnlyChange(
   }
 
   const propertyUpdates = change.propertyUpdates;
+  if (Object.keys(propertyUpdates).length === 0) {
+    return ChangeHotswapImpact.IRRELEVANT;
+  }
+
   for (const updatedPropName in propertyUpdates) {
     // ensure that only changes to the definition string result in a hotswap
     if (updatedPropName !== 'DefinitionString') {

packages/aws-cdk/test/api/hotswap/state-machine-hotswap-deployments.test.ts

@@ -637,3 +637,40 @@ test('knows how to handle attributes of the AWS::DynamoDB::Table resource', asyn
     }),
   });
 });
+
+test('does not explode if the DependsOn changes', async () => {
+  // GIVEN
+  setup.setCurrentCfnStackTemplate({
+    Resources: {
+      Machine: {
+        Type: 'AWS::StepFunctions::StateMachine',
+        Properties: {
+          DefinitionString: '{ Prop: "old-value" }',
+          StateMachineName: 'my-machine',
+        },
+        DependsOn: ['abc'],
+      },
+    },
+  });
+  const cdkStackArtifact = setup.cdkStackArtifactOf({
+    template: {
+      Resources: {
+        Machine: {
+          Type: 'AWS::StepFunctions::StateMachine',
+          Properties: {
+            DefinitionString: '{ Prop: "old-value" }',
+            StateMachineName: 'my-machine',
+          },
+        },
+        DependsOn: ['xyz'],
+      },
+    },
+  });
+
+  // WHEN
+  const deployStackResult = await hotswapMockSdkProvider.tryHotswapDeployment(cdkStackArtifact);
+
+  // THEN
+  expect(deployStackResult).not.toBeUndefined();
+  expect(mockUpdateMachineDefinition).not.toHaveBeenCalled();
+});