@dash-ui/styles/src/utils.ts

A tiny, powerful, framework-agnostic CSS-in-JS library.

/**
 * An FNV-1a hashing algorithm with a 32-bit offset basis. FNV-1a hashes are designed
 * to be fast while maintaining a low collision rate. The high dispersion rate makes
 * them well-suited for hashing nearly identical strings.
 *
 * @param string - A string you want to hash
 */
export function hash(string: string): string {
  // 32-bit offset basis
  let out = 2166136261;
  let i = 0;
  let len = string.length;

  for (; i < len; ++i)
    out =
      (out ^= string.charCodeAt(i)) +
      (out << 1) +
      (out << 4) +
      (out << 7) +
      (out << 8) +
      (out << 24);

  return (out >>> 0).toString(36);
}

const minL = /(^|[:;,{}\s])\s+|$/g;
const minR = / +{/g;

export function safeHash(
  key: string,
  hashFn: typeof hash
): (string: string) => string {
  const hashCache: Record<string, string> = {};
  let value: string | undefined;
  return (string: string): string => {
    if ((value = hashCache[string])) return value;
    value = hashFn(string.replace(minL, "$1").replace(minR, "{"));
    // allows class names to start with numbers
    return (hashCache[string] = value =
      !key && !isNaN(value[0] as any) ? "_" + value : value);
  };
}

export function noop(): void {}