JSON Formatter — JavaScript source

/**
 * JSON formatter - parse, pretty-print (2-space indent), and minify.
 *
 * Language: JavaScript (ES module)
 * CosmoDev polyglot showcase port of the `json-formatter` tool.
 * Ported from src/tools/JsonFormatter.tsx - display source, part of CosmoDev's
 * polyglot tool pages.
 *
 * Pure formatting logic extracted from the React island: trims the input,
 * JSON.parse's it, and re-stringifies. "beautify" emits with a configurable
 * indent (default 2, matching the island's JSON.stringify(parsed, null, 2));
 * "minify" emits compact. Parse failures surface the engine's error message
 * verbatim (or "Invalid JSON" for non-Error throws); empty/whitespace-only
 * input yields empty output with no error. Identical behavior to the typed
 * TypeScript port, minus the type annotations.
 */

/**
 * Format a JSON document the way the live island does.
 *
 * @param {string} input  Raw JSON text (leading/trailing whitespace ignored).
 * @param {'beautify'|'minify'} [mode='beautify'] 'beautify' (indented) or 'minify'.
 * @param {number} [indent=2] Indent width for 'beautify'.
 * @returns {{ output: string, error: string|null }}
 */
export function formatJson(input, mode = 'beautify', indent = 2) {
  const raw = input.trim();
  if (!raw) return { output: '', error: null };

  try {
    const parsed = JSON.parse(raw);
    const output =
      mode === 'minify'
        ? JSON.stringify(parsed)
        : JSON.stringify(parsed, null, indent);
    return { output, error: null };
  } catch (e) {
    return {
      output: '',
      error: e instanceof Error ? e.message : 'Invalid JSON',
    };
  }
}