add prefixZero utility

src/lib/index.ts

@@ -32,7 +32,8 @@ export {
 	getLabel,
 	getValue,
 	defaultIconProps,
-	capitalizeFirstLetter
+	capitalizeFirstLetter,
+	prefixZero
 } from './util';
 export {
 	type ToolbarToggleState,

src/lib/util.ts

@@ -88,8 +88,24 @@ export function targetMust<T extends HTMLElement>(event: Event): T {
 	return target;
 }
 
-/** capitalizeFirstLetter capitalizes the first letter of a string */
+/**
+ * capitalizeFirstLetter capitalizes the first letter of a string
+ * @param str The string to capitalize
+ * @returns The string with the first letter capitalized and all others lowercase
+ */
 export const capitalizeFirstLetter = (str: string): string => {
 	const lower = str.toLowerCase();
 	return lower.charAt(0).toUpperCase() + lower.slice(1);
 };
+
+/**
+ * prefixZero adds a leading zero to the string if it is less than 10
+ * @param str The string to prefix
+ * @returns The string with a leading zero if it was only 1 digit long
+ */
+export const prefixZero = (str: string): string => {
+	if (str.length === 1) {
+		return '0' + str;
+	}
+	return str;
+};