In programming language design, there's a process called bootstrapping:
In computer science, bootstrapping is the process of writing a compiler (or assembler) in the source programming language that it intends to compile.
This is a significant milestone in the evolution of programming languages, as it signifies a certain level of maturity, a point where the language has passed its first non-trivial test.
While discussing the concept with colleagues, I started wondering if a parallel could be drawn with fictional languages in literature. Has a fictional language reached the level of maturity necessary for the work that created it to be translated in it?
I'm mostly interested in published translations, with some indication that the translation is on par with the original work. Examples of what I'm looking for would be George Orwell's Nineteen Eighty-Four translated in Newspeak, or the works of J. R. R. Tolkien translated in Quenya. Perhaps even Star Trek novelizations in Klingon.