Function main

scripts/fungrim/recompile-drift.ts:46–157

()

type Artifact = { rules: CompiledFungrimRule[] };
type DivergenceAllow = {
  dropped?: Record<string, string>;
  added?: Record<string, string>;
  changed?: Record<string, string>;
};

/**
 * Deterministic serialization for content comparison: JSON with object keys
 * sorted at every level. Rule records are pure JSON data (no functions, no
 * undefined-bearing holes that matter), so equal stable strings ⇔ equal
 * content regardless of field order.
 */
function stableStringify(value: unknown): string {
  if (Array.isArray(value))
    return '[' + value.map(stableStringify).join(',') + ']';
  if (value !== null && typeof value === 'object') {
    const entries = Object.entries(value as Record<string, unknown>)
      .filter(([, v]) => v !== undefined)
      .sort(([a], [b]) => (a < b ? -1 : a > b ? 1 : 0));
    return (
      '{' +
      entries
        .map(([k, v]) => JSON.stringify(k) + ':' + stableStringify(v))
        .join(',') +
      '}'
    );
  }
  return JSON.stringify(value);
}

/** Short content fingerprint (FNV-1a, 32-bit) for compact drift reporting. */
function contentHash(value: unknown): string {
  const s = stableStringify(value);
  let h = 0x811c9dc5;
  for (let i = 0; i < s.length; i++) {
    h ^= s.charCodeAt(i);
    h = Math.imul(h, 0x01000193);
  }
  return (h >>> 0).toString(16).padStart(8, '0');
}

/** Top-level rule fields whose stable serialization differs between sides. */
function changedFields(
  a: CompiledFungrimRule,
  b: CompiledFungrimRule
): string[] {
  const keys = new Set([...Object.keys(a), ...Object.keys(b)]);
  return [...keys]
    .filter(
      (k) =>
        stableStringify((a as Record<string, unknown>)[k]) !==
        stableStringify((b as Record<string, unknown>)[k])
    )
    .sort();
}

function main(): void {
  const scriptDir = path.dirname(path.resolve(process.argv[1]));
  const rootDir = path.resolve(scriptDir, '../..');