Preview style

• Enforce empty lines before classes and functions with sticky leading comments (#3302)
• Reformat empty and whitespace-only files as either an empty file (if no newline is present) or as a single newline character (if a newline is present) (#3348)
• Implicitly concatenated strings used as function args are now wrapped inside parentheses (#3307)
• Correctly handle trailing commas that are inside a line's leading non-nested parens (#3370)

Configuration

• Fix incorrectly applied .gitignore rules by considering the .gitignore location and the relative path to the target file (#3338)
• Fix incorrectly ignoring .gitignore presence when more than one source directory is specified (#3336)

Parser

• Parsing support has been added for walruses inside generator expression that are passed as function args (for example, any(match := my_re.match(text) for text in texts)) (#3327).

Integrations

• Vim plugin: Optionally allow using the system installation of Black via let g:black_use_virtualenv = 0(#3309)