Not sure I made myself clear.  I understood the intent to apply the same edit three times, twice to one file, once to the other.
I was thinking that we only need one of the init_file or init_expected bundles; just use one bundle three times, twice in init, on each file, and once in test, applied to just one of the files.
But I don't know the language well enough to know whether applying the same edit_line bundle twice to a given file would skip the second time because it knows it's been done once, thus failing to test what you intended.