indentString

Indents each line in the provided string.

• Use String.prototype.replace() and a regular expression to add the character specified by indent count times at the start of each line.
• Omit the third argument, indent, to use a default indentation character of ' '.

const indentString = (str, count, indent = ' ') =>
  str.replace(/^/gm, indent.repeat(count));

indentString('Lorem\nIpsum', 2); // '  Lorem\n  Ipsum'
indentString('Lorem\nIpsum', 2, '_'); // '__Lorem\n__Ipsum'