Field Validation Using ES6 Syntax

is_field_valid_es6.js

const isNotEmpty = fieldName => fieldValue => fieldValue.trim().length > 0 || fieldName[0].toUpperCase() + fieldName.slice(1) + ' is required.';

const fieldName = isNotEmpty('name');
let isValid = fieldName('David');
console.log(isValid); // true
isValid = fieldName('');
console.log(isValid); // Name is required