Question
Is there a Dafny style? and a Dafny linter (style checker and bad smell warnings)?
Answer
There is a Dafny style guide here.
There is not yet a Dafny lint tool (that is, warnings about technically correct but suspicious or poor-style code), though a formatter is underway. Warnings about some matters are included in the Dafny parser. However, ideas for lint warnings are being collected and you are welcome to contribute ideas: suggestions can be made on the issues list.