sanitizeString

1/**
2 * Sanitizes a string by removing dangerous characters and normalizing whitespace.
3 * Commonly used to clean user input before further processing or display.
4 *
5 * @param input - The string to sanitize.
6 * @returns A cleaned and safe string.
7 */
8export function sanitizeString(input: string): string {
9  return input
10    .replace(/[<>\\/"'`;&]/g, '') // remove potentially dangerous characters
11    .replace(/\s+/g, ' ')           // collapse multiple whitespace
12    .trim();                         // remove leading/trailing whitespace
13}

1test('sanitizeString - removes HTML special characters', () => {
2  expect(sanitizeString('<script>alert("x")</script>')).toBe('scriptalert(x)/script');
3});
4
5test('sanitizeString - collapses multiple spaces', () => {
6  expect(sanitizeString('hello     world')).toBe('hello world');
7});
8
9test('sanitizeString - trims leading and trailing whitespace', () => {
10  expect(sanitizeString('   spaced out   ')).toBe('spaced out');
11});
12
13test('sanitizeString - handles combination of symbols and spaces', () => {
14  expect(sanitizeString(`  <div class="test">  hello   </div> `)).toBe('div classtest hello div');
15});
16
17test('sanitizeString - empty string', () => {
18  expect(sanitizeString('')).toBe('');
19});