Add string utility functions: splitLines

CHANGELOG.md

@@ -7,6 +7,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Added
+
+- `splitLine` string utility function
+
 ## [2.1.0] - 2025-09-03
 
 ### Added

src/lib/string.spec.ts

@@ -4,6 +4,7 @@ import {
   capitalize,
   uncapitalize,
   truncate,
+  splitLine,
   isValidSwissIbanNumber,
   isValidSwissSocialSecurityNumber,
 } from "./string";
@@ -129,6 +130,26 @@ describe("string tests", () => {
     expect(truncate(value, maxLength)).toBe(expected);
   });
 
+  test.each([
+    ["", []],
+    ["hello world\n", ["hello world", ""]],
+  ])("splitLine without the parameter to remove the empty entries", (str, expected) => {
+    expect(splitLine(str)).toEqual(expected);
+  });
+
+  test.each([
+    ["", []],
+    [null as unknown as string, []],
+    [undefined as unknown as string, []],
+    ["hello world", ["hello world"]],
+    ["hello world\n", ["hello world"]],
+    ["hello world\nhello world\nhello world", ["hello world", "hello world", "hello world"]],
+    ["hello world\rhello world\rhello world", ["hello world", "hello world", "hello world"]],
+    ["hello world\r\nhello world\r\nhello world", ["hello world", "hello world", "hello world"]],
+  ])("splitLine with the parameter to remove empty entries", (str, expected) => {
+    expect(splitLine(str, true)).toEqual(expected);
+  });
+
   test.each([
     [null as unknown as string, false],
     [undefined as unknown as string, false],

src/lib/string.ts

@@ -65,6 +65,21 @@ export function truncate(value: string | undefined, maxLength: number, suffix =
   return `${value.slice(0, maxLength)}${suffix}`;
 }
 
+/**
+ * Splits the string at line breaks
+ * @param str the string to split
+ * @param removeEmptyEntries the option to remove empty entries
+ * @returns the individual lines as an array
+ */
+export function splitLine(str: string, removeEmptyEntries: boolean = false): string[] {
+  if (isNullOrEmpty(str)) {
+    return [];
+  }
+
+  const splitted = str.split(/\r\n|\r|\n/);
+  return removeEmptyEntries ? splitted.filter((line) => !isNullOrWhitespace(line)) : splitted;
+}
+
 /**
  * Checks if the provided string is a valid swiss IBAN number
  * @param ibanNumber The provided IBAN number to check