Enhance func pathsToESModuleNameMapper

- Modified the regex in the mappings to return a cleaner module mappings
objects.

Author: iamWing

jest.config.mjs

@@ -21,13 +21,16 @@ function pathsToESModuleNameMapper() {
     const [key, val] = entry;
 
     if (/.*\(\.\*\)\$$/.test(key)) {
-      const convertedKey = `${key.substring(0, key.length - 1)}\\.js$`;
+      // eslint-disable-next-line prefer-template
+      const convertedKey = key.substring(0, key.length - 2)
+        + '[^\\.js])(\\.js)?$';
       esmMap[convertedKey] = val;
     }
-
-    esmMap[key] = val;
   });
 
+  // Append the mapping for relative paths without path alias.
+  esmMap['^(\\.{1,2}/.*)\\.js$'] = '$1';
+
   return esmMap;
 }