  Despite the immense popularity of the Automated Program Repair (APR) field,
the question of patch validation is still open. Most of the present-day
approaches follow the so-called Generate-and-Validate approach, where first a
candidate solution is being generated and after validated against an oracle.
The latter, however, might not give a reliable result, because of the
imperfections in such oracles; one of which is usually the test suite. Although
(re-) running the test suite is right under one's nose, in real life
applications the problem of over- and underfitting often occurs, resulting in
inadequate patches. Efforts that have been made to tackle with this problem
include patch filtering, test suite expansion, careful patch producing and many
more. Most approaches to date use post-filtering relying either on test
execution traces or make use of some similarity concept measured on the
generated patches. Our goal is to investigate the nature of these
similarity-based approaches. To do so, we trained a Doc2Vec model on an
open-source JavaScript project and generated 465 patches for 10 bugs in it.
These plausible patches alongside with the developer fix are then ranked based
on their similarity to the original program. We analyzed these similarity lists
and found that plain document embeddings may lead to misclassification - it
fails to capture nuanced code semantics. Nevertheless, in some cases it also
provided useful information, thus helping to better understand the area of
Automated Program Repair.
