BindingNinja

gem 'binding_ninja'

class Foo
  extend BindingNinja

  def foo(binding, arg1, arg2)
    p binding
    p arg1
    p arg2
  end
  auto_inject_binding :foo

  def foo2(binding, arg1, arg2)
    p binding
    p arg1
    p arg2
  end
  auto_inject_binding :foo2, if: ENV["ENABLE_BINDING_NINJA"]
  # or
  auto_inject_binding :foo2, if: ->(obj) { obj.enable_auto_inject_binding? }
  # or
  auto_inject_binding :foo2, if: :enable_auto_inject_binding?

  def enable_auto_inject_binding?
    true
  end
end

Foo.new.foo(1, 2) 
# => <Binding of toplevel>
# => 1
# => 2

# if ENABLE_BINDING_NINJA environment variable is nil or false,
# binding arguments is nil.
Foo.new.foo2(1, 2) 
# => nil
# => 1
# => 2

require "benchmark/ips"
require "binding_ninja"
require "binding_of_caller"

class Foo
  extend BindingNinja

  auto_inject_binding def foo1(b)
    b.local_variables
  end

  def foo2
    binding.of_caller(1).local_variables
  end

  def foo3(b)
    b.local_variables
  end
  auto_inject_binding :foo3, if: :enable_auto_inject_binding?

  def enable_auto_inject_binding?
    true
  end
end

foo = Foo.new

p foo.foo1
p foo.foo2
p foo.foo3

Benchmark.ips do |x|
  x.report("binding_ninja") { foo.foo1 }
  x.report("binding_ninja_with_condition") { foo.foo3 }
  x.report("binding_of_caller") { foo.foo2 }

  x.compare!
end