Add the option to preserve duplicate elements

Author: Gigabyte5671

README.md

@@ -58,3 +58,12 @@ Output:
     <a><img src="https://example.com/image" id="logo"></a>
 </body>
 ```
+
+
+## Options
+
+An options object can be passed as the second argument to `cssToHtml()` to customize the behaviour of the HTML generator.
+
+|    Option    |        Values        | Description |
+| :----------- | :------------------- | :---------- |
+| `duplicates` | `preserve`, `remove` |             |

src/Generator.ts

@@ -1,6 +1,7 @@
 type Combinator = '>' | '~' | '+';
 
 interface Options {
+	duplicates?: 'preserve' | 'remove';
 }
 
 /**
@@ -92,17 +93,19 @@ export function cssToHtml(css: CSSRuleList | string, options: Options = {}): HTM
 		};
 
 		function addElementToOutput (): void {
-			// If an identical element already exists, skip adding the new element.
-			const existingElements = Array.from(
-				(descriptor.combinator === '>' ?
-				descriptor.previousElement?.children :
-				descriptor.previousElement?.parentElement?.children) ?? output.children
-			);
-			const matchingElement = existingElements.find((element) => descriptor.matchesElement(element));
-			if (matchingElement) {
-				// Reference the matching element so properties such as `content` can cascade.
-				descriptor.previousElement = matchingElement as HTMLElement;
-				return;
+			if (options.duplicates !== 'preserve') {
+				// If an identical element already exists, skip adding the new element.
+				const existingElements = Array.from(
+					(descriptor.combinator === '>' ?
+					descriptor.previousElement?.children :
+					descriptor.previousElement?.parentElement?.children) ?? output.children
+				);
+				const matchingElement = existingElements.find((element) => descriptor.matchesElement(element));
+				if (matchingElement) {
+					// Reference the matching element so properties such as `content` can cascade.
+					descriptor.previousElement = matchingElement as HTMLElement;
+					return;
+				}
 			}
 			// Create the new element.
 			const newElement = document.createElement(descriptor.tag || 'div');