reduce upper & lower & add export default

String/Lower.js

@@ -12,12 +12,9 @@ const lower = (str) => {
     throw new TypeError('Invalid Input Type')
   }
 
-  return str
-    .replace(/[A-Z]/g, (_, indexOfUpperChar) => {
-      const asciiCode = str.charCodeAt(indexOfUpperChar)
-
-      return String.fromCharCode(asciiCode + 32)
-    })
+  return str.replace(
+    /[A-Z]/g, (char) => String.fromCharCode(char.charCodeAt() + 32)
+  )
 }
 
-export { lower }
+export default lower

String/Upper.js

@@ -12,13 +12,8 @@ const upper = (str) => {
   }
 
   return str.replace(
-    /[a-z]/g,
-    (_, indexOfLowerChar) => {
-      const asciiCode = str.charCodeAt(indexOfLowerChar)
-
-      return String.fromCharCode(asciiCode - 32)
-    }
+    /[a-z]/g, (char) => String.fromCharCode(char.charCodeAt() - 32)
   )
 }
 
-export { upper }
+export default upper

String/test/Lower.test.js

@@ -1,4 +1,4 @@
-import { lower } from '../Lower'
+import lower from '../Lower'
 
 describe('Testing the Lower function', () => {
   it('Test 1: Check by invalid type', () => {

String/test/Upper.test.js

@@ -1,6 +1,6 @@
-import { upper } from '../Upper'
+import upper from '../Upper'
 
-describe('Upper', () => {
+describe('Testing the Upper function', () => {
   it('return uppercase strings', () => {
     expect(upper('hello')).toBe('HELLO')
     expect(upper('WORLD')).toBe('WORLD')