Function isLineEmpty

lib/terminal.test.ts:1656–1660

* Helper to check if a line is empty (all spaces/null codepoints)

(term: Terminal, y: number)

   * Helper to check if a line is empty (all spaces/null codepoints)
   */
  function isLineEmpty(term: Terminal, y: number): boolean {
    const line = term.wasmTerm?.getLine(y);
    if (!line) return true;
    return line.every((c) => c.codepoint === 0 || c.codepoint === 32);
  }

  /**
   * Helper to get line content directly from viewport