[OpenAPI]: Refactor: replace Prism AST parser with Blueprinter Reflection API

[Abishekcs]

What this PR does?

Switch the Blueprinter parser from Prism-based AST parsing to Blueprinter's built-in Reflection API. This removes the need for a Visitor pattern, temp file parsing, and manual AST traversal. The Reflection API provides direct access to fields, views, and associations making the parser significantly simpler.

Example Code and Screenshot for basic Blueprinter fields: identifier, field, and fields

• routes.rb

Rage.routes.draw do
  root to: ->(env) { [200, {}, ["It works!"]] }

  get "/users/:id/blue", to: "users#show_blue"
end

• products_controller.rb

class UsersController < RageController::API
  
  # @response UserBlueprint
  def show_blue
    user = [{ uuid: 1, id: 101, name: "Alice", email: "alice@example.com", age: 25, first_name: "Alice", last_name: "loom", abishek: 'abi' }]
    render json: UserBlueprint.render(user)
  end
end

• user_blueprint.rb

class UserBlueprint < Blueprinter::Base
  identifier :uuid
  
  fields :id, :name, :email, :age
  
  field :email, name: :login   # -> "login": string

  field :abishek, name: :ad   # -> "login": string
  
  fields :first_name, :last_name

  field(:full_name) { |u| "#{u[:first_name]} #{u[:last_name]}" }
end

Example Code and Screnshoot of Blueprinter Inheritance

• routes.rb

Rage.routes.draw do
  root to: ->(env) { [200, {}, ["It works!"]] }

  get "/data_mining", to: "data_mining#show_data_mining"
end

• data_mining_controller.rb

class DataMiningController < RageController::API

  # @response DataMining
  def show_data_mining
    data_mining_details = { uuid: 'Third Edition', email: 'MorganKaufmann@publishers.com', name: 'Han Kamber Pei', first_name: 'Morgan', last_name: 'Kaufmann', hello_world: 'Earth', subject: "DataMining"  }
    render json: DataMining.render(data_mining_details)
  end
end

• data_mining_base.rb

class DataMiningBase < Blueprinter::Base
  field :hello_world
  field :email, name: :something
  fields :subject
end

• data_mining.rb

class DataMining < DataMiningBase
  identifier :uuid
  field "email", name: :login
  field "first_name"
  field :hello_world
end

• Blueprinter Response for route /data_mining

{
  "uuid": "Third Edition",
  "first_name": "Morgan",
  "hello_world": "Earth",
  "login": "MorganKaufmann@publishers.com",
  "something": "MorganKaufmann@publishers.com",
  "subject": "DataMining"
}

• OpenAPI response output for # @response DataMining

{
  "uuid": "string",
  "first_name": "string",
  "hello_world": "string",
  "login": "string",
  "something": "string",
  "subject": "string"
}

[Abishekcs]

At first I was using something like this:

    reflections = klass.reflections

    identifier_fields = {}
    default_fields = {}

    # identifier fields
    if (identifier_view = reflections[:identifier])
      identifier_view.fields.each do |_, field|
        identifier_fields[field.name.to_s] = { "type" => "string" }
      end
    end

    # default view fields
    if (default_view = reflections[:default])
      default_view.fields.each do |_, field|
        default_fields[field.name.to_s] = { "type" => "string" }
      end
    end

But .fields of Relection API seems to break for

 fields "first_name", :last_name

or for this too

field :email, name: "login"

[rsamoilov]

fields "first_name", :last_name

This seems to work fine for me with Blueprinter 1.2.1. But in any way, with this approach, we should only be relying on the official API. If some cases are not supported by the reflection API, it's safe to ignore them.

[Abishekcs]

@rsamoilov I have refactor Blueprinter parser using Reflection API just a quick summary:

• Added Gem Blueprinter
• Added a new mock class i.e spec/support/contexts/mocked_blueprinter_classes.rb. I am not sure if this was the right way or I should have made changes to the existing mocked_classess.rb.
• Existing test cases logic is same with just some minor changes.

[Abishekcs]

Only works with

• basic Blueprinter fields: identifier, field, and fields.
• Blueprinter Inheritance

[Abishekcs]

This is the only newly added line. Rest is same as mocked_classes.rb

[rsamoilov]

It should be safe to add this line to mocked_classes.rb. And you won't need a separate context then.

[Abishekcs]

@rsamoilov PR is ready to be reviewed again. Thank you!

• This test case was fully removed
• Switched back to using the official API
• Removed mocked_blueprinter_classes.rb and added few new lines in mocked_classes.rb
  which is:

    if block
      if defined?(Blueprinter::Base) && parent.ancestors.include?(Blueprinter::Base)
        klass.class_eval(block.call)
      else
        klass.class_eval(&block)
      end
    end

[rsamoilov]

🚀

[rsamoilov]

Suggested change

	if block
	if defined?(Blueprinter::Base) && parent.ancestors.include?(Blueprinter::Base)
	klass.class_eval(block.call)
	else
	klass.class_eval(&block)
	end
	end
	if block
	if defined?(Blueprinter::Base) && parent.ancestors.include?(Blueprinter::Base)
	klass.class_eval(block.call)
	end
	end

The else branch doesn't seem to be used, so it'd be better to remove it in the next PR.