One test still uses JUnit, but should be converted to Spock.

Make the input text field capable of handling rich text such that:

• Formatting like italic and bold is preserved
• Text can be copied from Word, unlike today, where text has to be copied via a plain text editor like Notepad

A window to paste text into and an "Alphabetize" button.
Bonus points for handling rich, formatted text.

It uses try-with-resource to read lines of a string, which must be converted to a groovy way. See:

• http://groovy-lang.org/differences.html
• http://mrhaki.blogspot.dk/2009/11/groovy-goodness-working-with-lines-in.html

Entries are currently sorted by text comparison. Some entries may start with a quote or double quote.

For example:
bee
"ape"

should be sorted as:
"ape"
bee

Try to handle this case:

level 1
        level 2 but with too much indent
  level 2 with proper indent

Lines 2 and 3 should have the same parent, line 1. It should be possible to guess by looking at the parent of line 2 and that the indent of line 1 and line 3 is not the same.

First, find out which tool to use.

Word, Pages, OpenOffice, Libre Office