Improving JSON.parse Error Context with Syntax Snippet

...
│     └─ Unexpected non-whitespace character after JSON at position 560

│     └─ Unexpected non-whitespace character after JSON at position 560
... Concern"]][["Counter
...           ^         

/**
 * Generate a context string for JSON syntax errors.
 *
 * Given a SyntaxError from JSON.parse and the original JSON string,
 * this function generates a two-line string that shows the error position.
 *
 * @param error - The SyntaxError object thrown by JSON.parse
 * @param jsonData - The original JSON string that caused the error
 * @param contextLength - The number of characters to show before and after the error position. Default is 10.
 * @returns A string showing the error context in the original JSON data.
 *
 * @example
 * const data = '[[1][2]]';
 * try { JSON.parse(data) }
 * catch (e: SyntaxError) {
 *   console.log('Error:', e.message)
 *   console.log(generateJsonErrorContext(e, data))
 * }
 * // Output:
 * // Error: Unexpected token a in JSON at position 4
 * // ...[[1][2]]
 * // ...    ^
 */
function generateJsonErrorContext(error: SyntaxError, jsonData: string, contextLength: number = 10): string {
  const match = /position (\d+)/.exec(error.message);
  if (!match) return 'Could not determine error position.'
  
  const position = parseInt(match[1], 10);
  const start = Math.max(0, position - contextLength);
  const end = Math.min(jsonData.length, position + contextLength);

  const context = jsonData.substring(start, end);
  const pointer = ' '.repeat(position - start) + '^';

  return `...${context}\n...${pointer}\n`;
}