Function decodeBase32

http/unstable_structured_fields_test.ts:711–731

(input: string)

const BASE32_ALPHABET = "ABCDEFGHIJKLMNOPQRSTUVWXYZ234567";

function decodeBase32(input: string): Uint8Array {
  // Remove padding
  input = input.replace(/=+$/, "").toUpperCase();
  if (input.length === 0) return new Uint8Array(0);

  const output: number[] = [];
  let bits = 0;
  let value = 0;

  for (const char of input) {
    const idx = BASE32_ALPHABET.indexOf(char);
    if (idx === -1) throw new Error(`Invalid base32 character: ${char}`);
    value = (value << 5) | idx;
    bits += 5;
    if (bits >= 8) {
      bits -= 8;
      output.push((value >> bits) & 0xff);
    }
  }
  return new Uint8Array(output);
}

// Convert test suite expected value to our internal format
// deno-lint-ignore no-explicit-any