Reduce array alloc on mount

CHANGELOG.md

@@ -12,6 +12,8 @@
 #### Fixes
 
 * [#2538](https://github.com/ruby-grape/grape/pull/2538): Fix validating nested json array params - [@mohammednasser-32](https://github.com/mohammednasser-32).
+* [#2543](https://github.com/ruby-grape/grape/pull/2543): Fix array allocation on mount - [@ericproulx](https://github.com/ericproulx).
+* Your contribution here.
 
 ### 2.3.0 (2025-02-08)
 

lib/grape/api.rb

@@ -55,7 +55,7 @@ def initial_setup(base_instance_parent)
  def override_all_methods!
  (base_instance.methods - Class.methods - NON_OVERRIDABLE).each do |method_override|
  define_singleton_method(method_override) do |*args, &block|
- add_setup(method_override, *args, &block)
+ add_setup(method: method_override, args: args, block: block)
  end
  end
  end
@@ -79,24 +79,24 @@ def configure
  # For instance, a description could be done using: `desc configuration[:description]` if it may vary
  # depending on where the endpoint is mounted. Use with care, if you find yourself using configuration
  # too much, you may actually want to provide a new API rather than remount it.
- def mount_instance(opts = {})
- instance = Class.new(@base_parent)
- instance.configuration = Grape::Util::EndpointConfiguration.new(opts[:configuration] || {})
- instance.base = self
- replay_setup_on(instance)
- instance
+ def mount_instance(configuration: nil)
+ Class.new(@base_parent).tap do |instance|
+  instance.configuration = Grape::Util::EndpointConfiguration.new(configuration || {})
+  instance.base = self
+  replay_setup_on(instance)
+ end
  end
 
+ private
+
  # Replays the set up to produce an API as defined in this class, can be called
  # on classes that inherit from Grape::API
  def replay_setup_on(instance)
  @setup.each do |setup_step|
- replay_step_on(instance, setup_step)
+ replay_step_on(instance, **setup_step)
  end
  end
 
- private
-
  def instance_for_rack
  if never_mounted?
  base_instance
@@ -106,34 +106,35 @@ def instance_for_rack
  end
 
  # Adds a new stage to the set up require to get a Grape::API up and running
- def add_setup(method, *args, &block)
- setup_step = { method: method, args: args, block: block }
- @setup += [setup_step]
+ def add_setup(step)
+ @setup << step
  last_response = nil
  @instances.each do |instance|
- last_response = replay_step_on(instance, setup_step)
+ last_response = replay_step_on(instance, **step)
  end
 
- # Updating all previously mounted classes in the case that new methods have been executed.
- if method != :mount && @setup.any?
- previous_mount_steps = @setup.select { |step| step[:method] == :mount }
- previous_mount_steps.each do |mount_step|
- refresh_mount_step = mount_step.merge(method: :refresh_mounted_api)
- @setup += [refresh_mount_step]
- @instances.each do |instance|
- replay_step_on(instance, refresh_mount_step)
- end
+ refresh_mount_step if step[:method] != :mount
+ last_response
+ end
+
+ # Updating all previously mounted classes in the case that new methods have been executed.
+ def refresh_mount_step
+ @setup.each do |setup_step|
+ next if setup_step[:method] != :mount
+
+ refresh_mount_step = setup_step.merge(method: :refresh_mounted_api)
+ @setup << refresh_mount_step
+ @instances.each do |instance|
+ replay_step_on(instance, **refresh_mount_step)
  end
  end
-
- last_response
  end
 
- def replay_step_on(instance, setup_step)
- return if skip_immediate_run?(instance, setup_step[:args])
+ def replay_step_on(instance, method:, args:, block:)
+ return if skip_immediate_run?(instance, args)
 
- args = evaluate_arguments(instance.configuration, *setup_step[:args])
- response = instance.send(setup_step[:method], *args, &setup_step[:block])
+ eval_args = evaluate_arguments(instance.configuration, *args)
+ response = instance.send(method, *eval_args, &block)
  if skip_immediate_run?(instance, [response])
  response
  else

spec/grape/api_spec.rb

@@ -1699,11 +1699,6 @@ def self.io
  expect(subject.io.string).to include(message)
  end
  end
-
- it 'does not unnecessarily retain duplicate setup blocks' do
- subject.logger
- expect { subject.logger }.not_to change(subject.instance_variable_get(:@setup), :size)
- end
  end
 
  describe '.helpers' do