created a clone method for xml-components

src/file/file.ts

@@ -328,7 +328,7 @@ export class File {
         // console.log("Generating content for paragraph: ", bookmarkId);
 
         // deep clone the original paragraph
-        const generatedParagraph = Object.assign(Object.create(Object.getPrototypeOf(paragraph)), paragraph);
+        const generatedParagraph = paragraph.clone() as Paragraph;
 
         generatedParagraph.clearPageBreaks().rightTabStop(9016, "dot");
 

src/file/paragraph/paragraph.spec.ts

@@ -393,4 +393,23 @@ describe("Paragraph", () => {
             });
         });
     });
+
+    describe("#clone", () => {
+        it("changes in a cloned paragraph must not affect the original paragraph", () => {
+            paragraph.pageBreakBefore();
+
+            const clonedParagraph = paragraph.clone() as file.Paragraph;
+            clonedParagraph.clearPageBreaks();
+
+            const tree = new Formatter().format(paragraph);
+            expect(tree).to.deep.equal({
+                "w:p": [{ "w:pPr": [{ "w:pageBreakBefore": [] }] }],
+            });
+
+            const clonedTree = new Formatter().format(clonedParagraph);
+            expect(clonedTree).to.deep.equal({
+                "w:p": [{ "w:pPr": [] }],
+            });
+        });
+    });
 });

src/file/xml-components/xml-component.ts

@@ -30,7 +30,6 @@ export abstract class XmlComponent extends BaseXmlComponent {
         };
     }
 
-    // TODO: Unused method
     public addChildElement(child: XmlComponent | string): XmlComponent {
         this.root.push(child);
 
@@ -40,4 +39,10 @@ export abstract class XmlComponent extends BaseXmlComponent {
     public delete(): void {
         this.deleted = true;
     }
+
+    public clone(): XmlComponent {
+        const newXmlComponent = Object.assign(Object.create(Object.getPrototypeOf(this)), this);
+        newXmlComponent.root = newXmlComponent.root.map((child) => (child instanceof XmlComponent ? child.clone() : child));
+        return newXmlComponent as XmlComponent;
+    }
 }