Function hasDriftedOnDisk

src/ui-server/api/source.ts:202–220

(
  projectRoot: string,
  storedPath: string,
  record: FileRecord
)

 * file) have their own handling in the endpoints that actually read.
 */
export function hasDriftedOnDisk(
  projectRoot: string,
  storedPath: string,
  record: FileRecord
): boolean {
  try {
    const absolute = resolveProjectFile(projectRoot, storedPath);
    const stats = fs.statSync(absolute);
    if (stats.size === record.size && Math.floor(stats.mtimeMs) === Math.floor(record.modifiedAt)) {
      return false;
    }
    // A file over the index's size limit is stored as its size stamp (#1910),
    // so it is compared as one — without reading it.
    const hashed = indexedHashInput(stats.size, () => fs.readFileSync(absolute, 'utf-8'));
    return createHash('sha256').update(hashed).digest('hex') !== record.contentHash;
  } catch {
    return false;
  }
}

/**
 * The drift verdict AND the file's length, from one read.