fix: duplicated comments

src/preprocess.test.ts

@@ -134,6 +134,46 @@ _ = {
 	],
 	c: "d"
 };
+`,
+		],
+		[
+			`
+const p = 'test';
+
+
+//pre comment
+//this is another pre comment
+if (a) b;
+//post comment
+
+someOtherCode();
+`,
+			`
+const p = 'test';
+
+
+//pre comment
+//this is another pre comment
+if(a){b}
+//post comment
+
+someOtherCode();
+`,
+		],
+		[
+			`
+// pre comment
+if (a)
+	// inner comment
+	b;
+// post comment
+`,
+			`
+// pre comment
+if(a){
+// inner comment
+b}
+// post comment
 `,
 		],
 	])("%s becomes %s", (input, expected, filepath = "test.ts") => {

src/reprintAst.ts

@@ -26,7 +26,10 @@ export function reprintAst(code: string, collectedNodes: CollectibleNode[]) {
 		// See https://github.com/prettier/prettier/issues/9114 for a Prettier AST format API.
 
 		// @ts-ignore
-		output += (generate.default || generate)(collectedNode, printOptions).code;
+		output += (generate.default || generate)(
+			collectedNode,
+			printOptions,
+		).code.trim();
 
 		lastEnd = collectedNode.end!;
 	}

src/traverseAndModifyAst.ts

@@ -15,6 +15,14 @@ export function traverseAndModifyAst(ast: Node) {
 			modifyNodeIfMissingBrackets(node) &&
 			nodeNotAlreadySeen(node, seenNodes)
 		) {
+			// Remove comments from the original node to avoid duplication
+			if (node.leadingComments) {
+				delete node.leadingComments;
+			}
+			if (node.trailingComments) {
+				delete node.trailingComments;
+			}
+
 			modifiedNodes.add(node);
 		}
 	}