How do you get the formula from a cell instead of the value?

Question

How do you get the literal value (the formula) from a cell instead of the result value?

EXAMPLE DESIRED:

• A2: \"Foo\"
• B3: \"=A2\" - so it

Answer 1

I had the same problem and tried to use the formula that Rubén created, but had a limitation. I couldn't use these formula inside of another one (I was trying to make a mid()). So made a different approach that worked:

function CELLFORMULA(reference) {
  var ss = SpreadsheetApp;
  var sheet = ss.getActiveSheet();
  var formula = ss.getActiveRange().getFormula();
  re = /cellformula\((.*)\);/g;
  args = re.exec(formula);
  try {
    var range = sheet.getRange(args[1]);
  }
  catch(e) {
    throw new Error(args + ' is not a valid range');
  }
  return range.getFormula();
}