Function executeOpenLine

src/vim/operators.ts:397–416

(
  direction: 'above' | 'below',
  ctx: OperatorContext,
)

 * Execute open line (o/O command).
 */
export function executeOpenLine(
  direction: 'above' | 'below',
  ctx: OperatorContext,
): void {
  const text = ctx.text
  const lines = text.split('\n')
  const { line: currentLine } = ctx.cursor.getPosition()

  const insertLine = direction === 'below' ? currentLine + 1 : currentLine
  const newLines = [
    ...lines.slice(0, insertLine),
    '',
    ...lines.slice(insertLine),
  ]

  const newText = newLines.join('\n')
  ctx.setText(newText)
  ctx.enterInsert(getLineStartOffset(newLines, insertLine))
  ctx.recordChange({ type: 'openLine', direction })
}

// ============================================================================
// Internal Helpers