(diagnostic
  (schema slovo.diagnostic)
  (version 1)
  (severity error)
  (code WhileBodyFormNotUnit)
  (message "`while` body forms must produce unit")
  (file "<fixture>")
  (span
    (bytes 53 54)
    (range 6 5 6 6)
  )
  (expected "unit")
  (found "i32")
)