CSNIPPEX: automated synthesis of compilable code snippets from Q&A sites.

ABSTRACT Popular Q&A sites like StackOverflow have collected numerous code snippets. However, many of them do not have complete type information, making them uncompilable and inapplicable to various software engineering tasks. This paper analyzes this problem, and proposes a technique CSNIPPEX to automatically convert code snippets into compilable Java source code files by resolving external dependencies, generating import declarations, and fixing syntactic errors. We implemented CSNIPPEX as a plug-in for Eclipse and evaluated it with 242,175 StackOverflow posts that contain code snippets. CSNIPPEX successfully synthesized compilable Java files for 40,410 of them. It was also able to effectively recover import declarations for each post with a precision of 91.04% in a couple of seconds.