feat(string): add truncateMiddle util

Author: unrevised6419

src/string.ts

@@ -39,3 +39,43 @@ export function initials(name: Maybe<string>): Optional<string> {
 
 	return parts.map((p) => p.toUpperCase()).join('');
 }
+
+/**
+ * There are cases where important information is at the end of the string and truncating the end isn't helpful.
+ * This function solves that.
+ *
+ * @license https://github.com/kahwee/truncate-middle#license
+ * @param str - String to be truncated
+ * @param frontLen - Number of characters to be remained in front
+ * @param backLen - Number of characters to be remained at the back
+ * @param truncateStr - String that replaces the truncated portion
+ * @returns Truncated string. Defaults to '&hellip;' if unspecified
+ */
+export function truncateMiddle(
+	str: Maybe<string>,
+	frontLen: number = 0,
+	backLen: number = 0,
+	truncateStr: string = '&hellip;',
+): string {
+	if (str == undefined) return '';
+
+	const strLen = str.length;
+	// Round to nearest integer instead of floor to fix decimal parameter test
+	const frontLength = Math.round(frontLen);
+	const backLength = Math.round(backLen);
+
+	if (
+		(frontLength === 0 && backLength === 0) ||
+		frontLength >= strLen ||
+		backLength >= strLen ||
+		frontLength + backLength >= strLen
+	) {
+		return str;
+	} else if (backLength === 0) {
+		return str.slice(0, frontLength) + truncateStr;
+	} else {
+		return (
+			str.slice(0, frontLength) + truncateStr + str.slice(strLen - backLength)
+		);
+	}
+}