sample-fix-import-category.js

function fixCategories() {                                                                                                                             
  var sheet = SpreadsheetApp.getActiveSheet();                                                                                                         
  var data = sheet.getDataRange().getValues();                                                                                                         
  var newData = new Array();                                                                                                                           
                                                                                                                                                       
  var map = {                                                                                                                                          
    'Subscriptions': ['netflix', 'google music'],                                                                                                      
    'Gas/Automotive': ['dmv'],                                                                                                                         
    'Groceries': ['safeway', 'trader joe', 'new seasons'],                                                                                             
    'Gym': ['fitness'],                                                                                                                                
  };                                                                                                                                                   
                                                                                                                                                       
  data.forEach(function(row, i) {                                                                                                                      
    var isPayment = new RegExp('payment', 'gi');                                                                                                       
                                                                                                                                                       
    if (i === 0) {                                                                                                                                     
      newData.push(row);                                                                                                                               
      return;                                                                                                                                          
    }                                                                                                                                                  
                                                                                                                                                       
    if (row[7] && !isPayment.test(row[5])) {                                                                                                           
      row[6] = -row[7];                                                                                                                                
    } else {                                                                                                                                           
      Object.keys(map).forEach(function(key) {                                                                                                         
        var found = map[key].filter(function(item) {                                                                                                   
          var regex = new RegExp(item, 'gi');                                                                                                          
          return regex.test(row[4]);                                                                                                                   
        }).length > 0;                                                                                                                                 
                                                                                                                                                       
        if (found) {                                                                                                                                   
          row[5] = key;                                                                                                                                
        }                                                                                                                                              
      });                                                                                                                                              
    }                                                                                                                                                  
    newData.push(row);                                                                                                                                 
  });                                                                                                                                                  
                                                                                                                                                       
  sheet.clearContents();                                                                                                                               
  sheet.getRange(1, 1, newData.length, newData[0].length).setValues(newData);                                                                          
}