Feature #14079
Updated by nate00 (Nate Sullivan) over 6 years ago
I would find it useful to check whether a list of arguments matches will cause an `ArgumentError` when passed to a method signature, method, but without calling the that method. I'd like to check the arguments list using a Maybe this method called, for example, would be called `respond_to_arguments?`. Here's an example: example, where I check whether I can pass various argument lists to `String#prepend`: ~~~ruby class Foobar def self.baz(str) end end str = "hello" # Foobar.baz String#prepend accepts 1 argument, not 0 or 2: Foobar.respond_to_arguments?(:baz, "one", "two") str.respond_to_arguments?(:prepend, "foo", "bar") # => false Foobar.respond_to_arguments?(:baz, "one") str.respond_to_arguments?(:prepend, "foo") # => true Foobar.respond_to_arguments?(:baz) str.respond_to_arguments?(:prepend) # => false # Indeed, we get an ArgumentError if we pass 0 or 2 arguments: Foobar.baz("one", "two") str.prepend("foo", "bar") # raises ArgumentError Foobar.baz("one") str.prepend("foo") # success! Foobar.baz str.prepend # raises ArgumentError ~~~ My use case is a background job processing system. It works like this: I call `MyWorker.perform_async` with some arguments; the arguments are serialized and put into a queue; and then a background worker takes those arguments from the queue, deserializes them and passes them to `MyWorker.perform`. If I passed invalid arguments, I don't know they were invalid until the background worker tries to call `perform`. But I'd like to know immediately when I call `perform_async`. Perhaps a `respond_to_arguments_missing?` method would be required also. Maybe `respond_to_arguments?` is a bad name. You could reasonably assume that it takes the same optional second parameter as `respond_to?` (i.e., `include_all`), but my proposal doesn't support an optional second parameter. Thank you for your consideration!