The ReScript formatter is deliberately opinionated and has no formatting configuration. The core team chooses formatting behavior to keep ReScript code consistent across projects and to keep the printer maintainable.
Bug reports and proposals are welcome, but formatter changes are evaluated by technical correctness, consistency with the language, implementation complexity, and core-team consensus. Similar behavior in another formatter is useful evidence, not by itself a reason to adopt a rule.
Some constructs preserve a source author's choice to make them multiline. For example, the printer preserves meaningful line breaks in pipe chains and records. These decisions describe current behavior rather than a general rule that all source line breaks must be retained.
When changing the formatter:
- test both narrow and wide print widths;
- cover comments and the parentheses needed to preserve parsing;
- run
make test-syntaxandmake test-syntax-roundtrip; - inspect snapshot changes for unrelated reformatting;
- prefer a simple rule that behaves consistently across equivalent AST shapes.
The implementation map and diagnostic commands are in README.md.