Beatrice Mwangi

A formatter settles arguments that should never have been opened, which leaves one decision worth having: which tool the project commits to. Everything after that is configuration. The current field has converged on two implementations with the same goal. Prettier has the larger plugin ecosystem and a stable output model; Biome is written in Rust, is substantially faster on large files, and covers formatting and linting in one pass with its own configuration. Both produce readable output and both will change a file the moment somebody saves it. Adopting one is a project decision, not a preference. Configuration discovery is where people get stuck. Both tools read a configuration file, resolve it from the directory being formatted, and ignore paths listed in an ignore file. Running a formatter from the wrong directory changes which configuration applies, so the output changes without anybody editing the rules. Format and lint are different jobs with an ordering. A linter reports problems; a formatter rewrites files. Running lint with a fix option and formatting at the same time produces two passes over the same file and a diff nobody can read. I fix the order first, then configure. I have a view on print width and no interest in arguing it. A formatter that disagrees with hand-written code produces a first commit of pure reformatting, and that commit has to be separate from any functional change or the review is unreadable. The practical recommendation on every page is the same: adopt one tool, format once on a clean branch, and then let it run on save forever.