How to use Ruby forward arguments notation ...

#code #summary #codesummary

October 20, 2022

# How to use Ruby forward arguments notation ... # Part 1: An example of a simple reporting module puts RUBY_VERSION # 3.1.2 class Provider def report(message, object, *args, **kwargs, &) = puts "Provider work" end # Forward arguments notation helps forward all arguments to a method call module Reporting # First parameter is defined, the rest are not needed def self.log(message, ...) puts message before(...) console_logging(message, ...) error_reporting(...) end # Only the &block is needed so everything else is ignored def self.before(*_, **_, &block) = block&.call("#{self.name}##{__method__}") # Using all params thus ... is not used def self.console_logging(message, object, *args, **kwargs, &block) puts "Message <#{message}>: #{object} with args: #{args} and kwargs: #{kwargs} with block: #{block}" end # Forward all params def self.error_reporting(...) = Provider.new.report(...) end # Sample usage Admin=Struct.new(:name, keyword_init: true) admin=Admin.new(name: "Alex") step=3 Reporting.log("Test message", admin, step, config: { app: true }) do puts "Executing this around logging" end
# Part 2: An example of a service calling multiple other objects module User class CreateService def call(object, ...) Reporting.log("starting service", object, ...) Validate.new(object).call(...) .then { Converter.new(object).call(...) } .then { Repo.new(object).update(...) } Reporting.log("finished service", object, ...) end end end # # This is how I define more things module User class Validate def initialize(object) = @object = object def call(*args, **kwargs, &block) = block&.call("#{self.class}##{__method__}") end class Converter def initialize(object) = @object = object def call(*args, **kwargs, &block) = block&.call("#{self.class}##{__method__}") end class Repo def initialize(object) = @object = object def update(*args, **kwargs, &block) = block&.call("#{self.class}##{__method__}") end end
# Part 3: Example of usage for the User::CreateService user=Admin.new(name: "The Admin") payload=2 # Can be called with positional params User::CreateService.new.call(user, payload) # Can be called with positional params and keyword params User::CreateService.new.call(user, payload, config: { app: true }) # Can be called with positional params, keyword params, and block User::CreateService.new.call(user, payload, config: { app: true }) do |method_name| puts "executed from #{method_name}" end

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