call-arity

Flag a call that no visible method of the function accepts: a positional count outside every method’s range, or a keyword argument no positionally-matching method declares. Such a call raises MethodError at runtime. The method table unions every tier name resolution sees — the file’s own definitions, the workspace package, and the harvested library, qualified extensions included — so an unknown method always silences the check rather than triggering it. Calls that splat arguments, carry do blocks, sit in macro calls or quoted code, or target constructors and callable values are exempt, and a file that evals or includes outside a known workspace is skipped entirely. Off by default: the rule needs project context to be sound, so the language server enables it for workspace member files, while the CLI leaves it opt-in for self-contained scripts.

half has no two-argument method:

half(x) = x / 2

half(3, 4)

warning: call-arity
 --> example.jl:3:1
  |
3 | half(3, 4)
  | ^^^^^^^^^^ no method of `half` takes 2 positional arguments (methods accept 1)