account for delimiters in structured data replacements

Fixes #6028

Author: seankhliao

api/filters/replacement/replacement.go

@@ -191,7 +191,7 @@ func copyValueToTarget(target *yaml.RNode, value *yaml.RNode, selector *types.Ta
 		}
 
 		// Check if this fieldPath contains structured data access
-		if err := setValueInStructuredData(target, value, fp, createKind); err == nil {
+		if err := setValueInStructuredData(target, value, fp, selector.Options); err == nil {
 			// Successfully handled as structured data
 			continue
 		}
@@ -258,7 +258,7 @@ func setFieldValue(options *types.FieldOptions, targetField *yaml.RNode, value *
 }
 
 // setValueInStructuredData handles setting values within structured data (JSON/YAML) in scalar fields
-func setValueInStructuredData(target *yaml.RNode, value *yaml.RNode, fieldPath string, createKind yaml.Kind) error {
+func setValueInStructuredData(target *yaml.RNode, value *yaml.RNode, fieldPath string, options *types.FieldOptions) error {
 	pathParts := kyaml_utils.SmarterPathSplitter(fieldPath, ".")
 	if len(pathParts) < 2 {
 		return fmt.Errorf("not a structured data path")
@@ -309,6 +309,11 @@ func setValueInStructuredData(target *yaml.RNode, value *yaml.RNode, fieldPath s
 
 	structuredData := yaml.NewRNode(&parsedNode)
 
+	createKind := yaml.Kind(0) // do not create
+	if options != nil && options.Create {
+		createKind = value.YNode().Kind
+	}
+
 	// Navigate to the target location within the structured data
 	targetInStructured, err := structuredData.Pipe(&yaml.PathMatcher{
 		Path:   structuredDataPath,
@@ -329,10 +334,9 @@ func setValueInStructuredData(target *yaml.RNode, value *yaml.RNode, fieldPath s
 
 	// Set the value in the structured data
 	for _, t := range targetFields {
-		if t.YNode().Kind == yaml.ScalarNode {
-			t.YNode().Value = value.YNode().Value
-		} else {
-			t.SetYNode(value.YNode())
+		err = setFieldValue(options, t, value)
+		if err != nil {
+			return err
 		}
 	}
 

api/filters/replacement/replacement_test.go

@@ -5005,6 +5005,56 @@ data:
     labels: {app: "my-awesome-app", version: "1.0.0", env: "production"}
     spec: {replicas: 3, selector: {matchLabels: {app: "my-awesome-app"}}}`,
 		},
+		"replacement yaml substring options": {
+			input: `apiVersion: v1
+kind: ConfigMap
+metadata:
+  name: source-values
+data:
+  app_name: "my-awesome-app"
+---
+apiVersion: v1
+kind: ConfigMap
+metadata:
+  name: target-config
+data:
+  config.yaml: |-
+    target:
+      url: https://example.com/appname/api/endpoint
+`,
+
+			replacements: `replacements:
+- source:
+    kind: ConfigMap
+    name: source-values
+    fieldPath: data.app_name
+  targets:
+  - select:
+      kind: ConfigMap
+      name: target-config
+    fieldPaths:
+    - data.config\.yaml.target.url
+    options:
+      delimiter: /
+      index: 3
+`,
+			expected: `apiVersion: v1
+kind: ConfigMap
+metadata:
+  name: source-values
+data:
+  app_name: "my-awesome-app"
+---
+apiVersion: v1
+kind: ConfigMap
+metadata:
+  name: target-config
+data:
+  config.yaml: |-
+    target:
+      url: https://example.com/my-awesome-app/api/endpoint
+`,
+		},
 	}
 
 	for tn := range testCases {