Function isBinaryContent

src/constants/files.ts:131–156

(buffer: Buffer)

 * or a high proportion of non-printable characters.
 */
export function isBinaryContent(buffer: Buffer): boolean {
  // Check first BINARY_CHECK_SIZE bytes (or full buffer if smaller)
  const checkSize = Math.min(buffer.length, BINARY_CHECK_SIZE)

  let nonPrintable = 0
  for (let i = 0; i < checkSize; i++) {
    const byte = buffer[i]!
    // Null byte is a strong indicator of binary
    if (byte === 0) {
      return true
    }
    // Count non-printable, non-whitespace bytes
    // Printable ASCII is 32-126, plus common whitespace (9, 10, 13)
    if (
      byte < 32 &&
      byte !== 9 && // tab
      byte !== 10 && // newline
      byte !== 13 // carriage return
    ) {
      nonPrintable++
    }
  }

  // If more than 10% non-printable, likely binary
  return nonPrintable / checkSize > 0.1
}