Checkmate/src/Utils/stringUtils.js

/**
 * Helper function to get first letter capitalized string
 * @param {string} str String whose first letter is to be capitalized
 * @returns A string with first letter capitalized
 */
export const capitalizeFirstLetter = (str) => {	
  if (str === null || str === undefined) {
		return "";
	}
	if (typeof str !== "string") {
		throw new TypeError("Input must be a string");
	}
	if (str.length === 0) {
		return "";
	}  
	return str.charAt(0).toUpperCase() + str.slice(1);
};

/**
 * Helper function to get first letter as a lower case string
 * @param {string} str String whose first letter is to be lower cased
 * @returns A string with first letter lower cased
 */

export const toLowerCaseFirstLetter = (str) => {	
	if (str === null || str === undefined) {
		  return "";
	  }
	  if (typeof str !== "string") {
		  throw new TypeError("Input must be a string");
	  }
	  if (str.length === 0) {
		  return "";
	  }  
	  return str.charAt(0).toLowerCase() + str.slice(1);
  };