fix(s3-deployment): skip replacement pass when no source markers

packages/@aws-cdk-testing/framework-integ/test/aws-s3-deployment/test/integ.bucket-deployment-large-file.js.snapshot/test-bucket-deployment-large-file.template.json

@@ -405,7 +405,7 @@
      "S3Bucket": {
       "Fn::Sub": "cdk-hnb659fds-assets-${AWS::AccountId}-${AWS::Region}"
      },
-     "S3Key": "3423a042b818e31c1e34a19d6689ab2e5f9b70fcbe9e71df66f241b20a200bd9.zip"
+     "S3Key": "fbc0c6f6cf1d34be4fad26e77840e9068ff1f4e94fe80e26a0d6527bb8e6a9d1.zip"
     },
     "Environment": {
      "Variables": {

packages/@aws-cdk-testing/framework-integ/test/aws-s3-deployment/test/integ.bucket-deployment-large-file.ts

@@ -162,10 +162,11 @@ const noEscapeFileWithMarker = Source.jsonData('my-json/secret-config-no-escape.
   secret_value: param.stringValue,
 });
 
-// Deploy the large files
+const deploymentSources = [largeJsonSource, largeTextSource, fileWithMarker, noEscapeFileWithMarker];
+
 new BucketDeployment(stack, 'DeployWithLargeFiles', {
   destinationBucket: bucket,
-  sources: [largeJsonSource, largeTextSource, fileWithMarker, noEscapeFileWithMarker],
+  sources: deploymentSources,
   retainOnDelete: false,
 });
 

packages/@aws-cdk/custom-resource-handlers/lib/aws-s3-deployment/bucket-deployment-handler/index.py

@@ -336,6 +336,9 @@ def extract_and_replace_markers(archive, contents_dir, markers, markers_config):
     with ZipFile(archive, "r") as zip:
         zip.extractall(contents_dir)
 
+        if not markers:
+            return
+
         # replace markers for this source
         for file in zip.namelist():
             file_path = os.path.join(contents_dir, file)

packages/@aws-cdk/custom-resource-handlers/test/aws-s3-deployment/bucket-deployment-handler/test.py

@@ -725,6 +725,14 @@ def test_replace_markers(self):
                     else:
                         self.assertEqual(content, '{\n    "root": {\n        "key_with_quote": "prefixvalue"with"quotessuffix",\n        "key_without_quote": "prefixboom-marker2-replacedsuffix"\n    }\n}')
 
+    def test_extract_and_replace_markers_skips_sources_without_markers(self):
+        with tempfile.TemporaryDirectory() as outdir:
+            with patch.object(index, 'replace_markers') as replace_markers:
+                index.extract_and_replace_markers(os.path.join(scriptdir, "test.zip"), outdir, {}, {})
+
+            replace_markers.assert_not_called()
+            self.assertTrue(os.path.exists(os.path.join(outdir, "test.txt")))
+
     def test_marker_substitution(self):
         outdir = tempfile.mkdtemp()
 
@@ -846,4 +854,4 @@ def assert_field(name, expect=None):
     return resp
 
 if __name__ == '__main__':
-    unittest.main()
+    unittest.main()