With the method_arguments gem you can easily set object attributes from method arguments.
Transform this:
def initialize(user_entity, first_name:, last_name:, email:, phone:, dob:)
@user_entity = user_entity
@first_name = first_name
@last_name = last_name
@email = email
@phone = phone
@dob = dob
endinto this streamlined version:
def initialize(user_entity, first_name:, last_name:, email:, phone:, dob:)
set_instance_vars(__method_args__)
endWithin any method, call __method_args__ to retrieve its arguments as a Hash.
def initialize(user_entity, first_name:, last_name:, age:, **kw_rest)
"Method ##{__method__} received #{__method_args__.inspect} arguments"
endLimitations
-
Argument types
*restand**keyrestare ignored regardless of their name:def initialize(arg, *arg_rest, kw_arg:, **kw_rest) __method_args__ # returns { a: <value>, kw_arg: <value> } end
Casting unknown arbitrary arguments to instance variables is not recommended for security reasons.
-
The method does not support argument forwarding:
def self.call(...) new(__method_args__).call # raises error end
Use set_instance_vars(hash) to assign instance variables from a Hash.
To leverage setters (attribute writers), add use_writers: true argument. If a writer with the corresponding name exists, it will be invoked.
Example
Before:
def initialize(user_entity, first_name:, last_name:, age:)
@user_entity = user_entity
@first_name = first_name
@last_name = last_name
self.age = age
end
def age=(val)
@age = Integer(val)
endAfter:
def initialize(user_entity, first_name:, last_name:, age:, ...)
set_instance_vars(__method_args__, use_writers: true)
end
def age=(val)
@age = Integer(val)
end-
Add to your Gemfile, then run
bundle install:gem "method_arguments"
-
Prepend your code with
require "method_arguments"
This gem is designed to be compatible with Ruby 2.7 and above. It has been tested on the following MRI versions:
- v2.7.2
- v3.0.3
- v3.1.2
If you encounter any issues with later versions, please feel free to report them.