To Pascal Case

1/**
2 * Converts a string to PascalCase.
3 *
4 * Handles acronyms properly, ensuring that something like
5 * "XMLHttpRequest" becomes "XmlHttpRequest".
6 *
7 * @param str - The input string.
8 * @returns The PascalCased string.
9 *
10 * @example
11 * toPascalCase("hello world-example"); // "HelloWorldExample"
12 * toPascalCase("XMLHttpRequest"); // "XmlHttpRequest"
13 */
14export function toPascalCase(str: string): string {
15  return (
16    str
17      // Split acronym groups into proper boundaries
18      .replace(/([A-Z]+)([A-Z][a-z])/g, '$1 $2')
19      // Split between lowercase/digit and uppercase
20      .replace(/([a-z\d])([A-Z])/g, '$1 $2')
21      // Normalize spaces/underscores/dashes
22      .replace(/[-_\s]+/g, ' ')
23      // Lowercase all to normalize
24      .toLowerCase()
25      // Capitalize every word
26      .replace(/\b\w/g, (c) => c.toUpperCase())
27      // Remove spaces
28      .replace(/\s+/g, '')
29  );
30}