// Having a text frame selected.
// ---
var tf = app.selection[0];

var lines        = tf.lines.everyItem().contents;
var ranges       = tf.textStyleRanges.everyItem().contents;
var lines_ranges = tf.lines.everyItem().textStyleRanges.everyItem().contents;

var result =
[
  "Lines:\r\r- " + lines.join('\r- '),
  "Ranges:\r\r- " + ranges.join('\r- '),
  "Lines_Ranges:\r\r- " + lines_ranges.join('\r- ')
].join('\r\r==================\r\r');

alert( result );