Getafix: How Facebook tools learn to fix bugs automatically

Introduced Getafix, a novel tool that automatically finds and suggests fixes for bugs identified by static analysis (Infer) and automated testing (Sapienz). Getafix leverages hierarchical clustering and anti-unification to learn fix patterns from past code changes, considering both the edit and its surrounding context. It employs a tree differencer to identify granular edits and a pattern mining process that generates abstract fix patterns with 'holes' for context-specific instantiation. This enables more intelligent and context-aware bug remediation than simpler auto-fix tools.