Function readStringAt

src/resolution/frameworks/expo-router.ts:239–282

(s: string, at: number)

 * with every `${…}` replaced by {@link HOLE}. Null when `at` is not a string.
 */
export function readStringAt(s: string, at: number): string | null {
  const q = s[at];
  if (q === '"' || q === "'") {
    let out = '';
    for (let i = at + 1; i < s.length; i++) {
      const ch = s[i]!;
      if (ch === '\\') {
        out += s[i + 1] ?? '';
        i++;
        continue;
      }
      if (ch === q) return out;
      out += ch;
    }
    return null;
  }
  if (q === '`') {
    const end = skipTemplate(s, at);
    let out = '';
    for (let i = at + 1; i < end; i++) {
      const ch = s[i]!;
      if (ch === '\\') {
        out += s[i + 1] ?? '';
        i++;
        continue;
      }
      if (ch === '$' && s[i + 1] === '{') {
        let depth = 0;
        for (i = i + 1; i < end; i++) {
          if (s[i] === '{') depth++;
          else if (s[i] === '}') {
            depth--;
            if (depth === 0) break;
          }
        }
        out += HOLE;
        continue;
      }
      out += ch;
    }
    return out;
  }
  return null;
}

export interface HrefLiteral {
  /** The path part, `${…}` holes kept as {@link HOLE}; query and hash removed. */