How to remove leading spaces from all lines in a Google Doc?

Question

What is an easy way to remove all leading spaces from lines in a Google Doc?

E.g. if copy-pasting a large amount of text that has been indented with spaces, such as

Lorem ipsum dolor sit amet, consectetur adipiscing elit.
  Nullam mollis nulla sit amet metus eleifend, in eleifend metus facilisis.
  Aenean tempor diam sed quam fringilla dignissim.
    Pellentesque in sem aliquam, ultricies purus et, dapibus mi.
  Aliquam sit amet diam sed eros aliquam faucibus ac auctor sapien.
    Suspendisse consectetur mauris commodo tellus dignissim bibendum in in risus.

Should become:

Lorem ipsum dolor sit amet, consectetur adipiscing elit.
Nullam mollis nulla sit amet metus eleifend, in eleifend metus facilisis.
Aenean tempor diam sed quam fringilla dignissim.
Pellentesque in sem aliquam, ultricies purus et, dapibus mi.
Aliquam sit amet diam sed eros aliquam faucibus ac auctor sapien.
Suspendisse consectetur mauris commodo tellus dignissim bibendum in in risus.

Answer 1

You can use the following script:

function LeadingBlanks() {

  var document = DocumentApp.getActiveDocument();
  var lblanks = "";

  var regExp = "^[[:blank:]]*";
  document.replaceText(regExp, lblanks);

}

EDIT

As suggested by Vincent Scheib the above code can be further compacted/simplified

function LeadingBlanks() {
  var document = DocumentApp.getActiveDocument();
  var regExp = "^ *";
  document.replaceText(regExp, "");    
}