fix(services): improve validation PUT /users/current

src/tools/utils/parseStringNullish.ts

@@ -1,21 +1,25 @@
 /**
  * Parse a nullish string:
+ *  - if `string === undefined`, it returns `defaultString`
+ *  - if `string === null`, it returns `null`
  *  - if `string.length === 0`, it returns `null`
- *  - if `string == null`, it returns `defaultString`
- *  - if `string.length > 0`, it returns `string`
+ *  - else, it returns `string`
  * @param defaultString
  * @param string
  * @returns
  */
 export const parseStringNullish = (
   defaultString: string | null,
-  string?: string
+  string?: string | null
 ): string | null => {
-  if (string != null) {
-    if (string.length > 0) {
-      return string
-    }
+  if (string === undefined) {
+    return defaultString
+  }
+  if (string === null) {
     return null
   }
-  return defaultString
+  if (string.length === 0) {
+    return null
+  }
+  return string
 }