Prettier vs Scalafmt

Prettier is an open-source code formatter that parses source files and prints them in a consistent style while accounting for line length. Its built-in languages include JavaScript, JSX, Angular, Vue, Flow, TypeScript, CSS, Less, SCSS, HTML, JSON, GraphQL, Markdown, YAML, LWC, and MJML. The command-line interface can write formatted files with --write or check formatting with --check in continuous integration. Listed editor integrations include VS Code, Emacs, Vim, Helix, Sublime Text, JetBrains IDEs, Visual Studio, and Espresso; formatting can run from a shortcut or on save. Prettier has configuration options but keeps them limited. Plugins can add languages and formatting rules, and languages outside the built-in set require a plugin. For ESLint integration, the installation guidance recommends eslint-config-prettier to disable rules that are unnecessary or may conflict. Prettier supports browser and JavaScript API use, along with Linux, macOS, and Windows. The listed plan is free. Commercial support and maintenance are available through the Tidelift Subscription.

Scalafmt is a free Scala code formatter for keeping formatting consistent across a team. It handles Scala 2, Scala 3, sbt files and Scala scripts, with one dialect selected for each file. Formatting options are stored in a plain-text .scalafmt.conf file using HOCON syntax. Since version 3.1.0, the configuration must explicitly specify both the version and runner.dialect. Scalafmt can run from an editor, build tool or terminal. Documented editor integrations include IntelliJ, VS Code, Vim, NeoVim, Emacs, Sublime Text and Eclipse; Metals supports formatting requests from editors. It integrates with sbt and documents integrations for Maven, Gradle and Mill. Command-line check and test modes report misformatted code without writing changes. It also supports ignoring files, changed-lines formatting and a library API. IntelliJ range formatting uses IntelliJ’s own formatter by default: Scalafmt is designed primarily for whole files, and selected ranges may produce undesirable results. The project license is Apache-2.0.