Google Sheets Split Cell CSV Values to Rows

cellCSVSplitToRows.js

// select the 1 or more rows to set the active range
function cellCSVSplitToRows() {
  const sheet = SpreadsheetApp.getActiveSheet()
  const aRange = sheet.getActiveRange()
  let rowTracker = 0
    
  function setFeatures(range) {
    const startIndex = range.getRowIndex()
    // target the column with CSV content here
    const fColIndex = 3
    const features = range.getCell(1,fColIndex).getValue().split(',').map(f => [f])
    const rows = features.length
    const destRange = sheet.getRange(startIndex + 1, fColIndex, rows, 1)
    const featureColumnRange = sheet.getRange(startIndex + 1, fColIndex, rows, 1)

    sheet.insertRowsAfter(startIndex, rows)
    destRange.setValues(features)
    rowTracker += (rows + 1)
  }
  
  const arEnd = aRange.getLastRow()
  const arStart = aRange.getRowIndex()
  for(let i = arStart; i <= arEnd; i++) {
    let currentStart = arStart + rowTracker
    let r = sheet.getRange('Sheet1!A'+ currentStart + ':W' + currentStart)
    setFeatures(r)
  }
}