feat: make generated require ESM compatible

Author: bdezso

lib/plugin/utils/plugin-utils.ts

@@ -137,6 +137,16 @@ export function hasPropertyKey(
     .some((item) => item.name.getText() === key);
 }
 
+function getOutputExtension(fileName: string): string {  
+  if (fileName.endsWith('.mts')) {
+    return '.mjs';
+  } else if (fileName.endsWith('.cts')) {
+    return '.cjs';
+  } else{
+    return ".js";
+  }
+}
+
 export function replaceImportPath(
   typeReference: string,
   fileName: string,
@@ -190,6 +200,10 @@ export function replaceImportPath(
       if (indexPos >= 0) {
         relativePath = relativePath.slice(0, indexPos);
       }
+    } else {
+      // Add appropriate extension for non-node_modules imports
+      const extension = getOutputExtension(fileName);
+      relativePath += extension;
     }
 
     typeReference = typeReference.replace(importPath, relativePath);
@@ -203,6 +217,7 @@ export function replaceImportPath(
         importPath: relativePath
       };
     }
+
     return {
       typeReference: typeReference.replace('import', 'require'),
       importPath: relativePath