Stable style

• Fix unwanted crashes caused by AST equivalency check (#4290)

Preview style

• if guards in case blocks are now wrapped in parentheses when the line is too long. (#4269)
• Stop moving multiline strings to a new line unless inside brackets (#4289)

Integrations

• Add a new option use_pyproject to the GitHub Action psf/black. This will read the Black version from pyproject.toml. (#4294)