chore: change error message, add UT

src/resolve/sourceComponent.ts

@@ -232,7 +232,9 @@ export class SourceComponent implements MetadataComponent {
     const uniqueElement = this.type.uniqueIdElement;
     const matched = uniqueElement ? children.find((c) => getString(c, uniqueElement) === this.name) : undefined;
     if (!matched) {
-      throw new SfError(`Unable to find matching parent xml file for ${this.xml}`);
+      throw new SfError(
+        `Invalid XML tags or unable to find matching parent xml file for ${this.type.name} "${this.name}"`
+      );
     }
     return matched;
   }

test/resolve/sourceComponent.test.ts

@@ -15,6 +15,7 @@ import {
   CHILD_1_NAME,
   CHILD_1_XML,
   CHILD_2_NAME,
+  CHILD_2_XML,
   COMPONENT_1,
   COMPONENT_1_XML,
   COMPONENT_1_XML_PATH,
@@ -37,6 +38,7 @@ import {
 } from '../mock/type-constants/customObjectTranslationConstant';
 import { DecomposedSourceAdapter } from '../../src/resolve/adapters';
 import { DE_METAFILE } from '../mock/type-constants/digitalExperienceBundleConstants';
+import { XML_NS_KEY, XML_NS_URL } from '../../src/common';
 import { RegistryTestUtil } from './registryTestUtil';
 
 Messages.importMessagesDirectory(__dirname);
@@ -487,6 +489,24 @@ describe('SourceComponent', () => {
       expect(COMPONENT_1.parseFromParentXml(COMPONENT_1_XML)).to.deep.equal(COMPONENT_1_XML);
     });
 
+    it('throw an error when it cant find the parent xml', () => {
+      try {
+        expectedChild.parseFromParentXml({
+          // notice "B" not "b"
+          CustomLaBels: {
+            [XML_NS_KEY]: XML_NS_URL,
+            [type.directoryName]: [CHILD_1_XML, CHILD_2_XML],
+          },
+        });
+        assert.fail('this should throw');
+      } catch (e) {
+        assert(e instanceof Error);
+        expect(e.message).to.equal(
+          'Invalid XML tags or unable to find matching parent xml file for CustomLabel "Child_1"'
+        );
+      }
+    });
+
     // https://github.com/forcedotcom/salesforcedx-vscode/issues/3210
     it('should return empty children for types that do not have uniqueIdElement but xmlPathToChildren returns elements', () => {
       const noUniqueIdElementType: MetadataType = JSON.parse(JSON.stringify(MATCHING_RULES_TYPE));