Don't raise an error without configuration, use default config instead

lib/doorkeeper.rb

@@ -114,11 +114,77 @@ module SecretStoring
     autoload :BCrypt, "doorkeeper/secret_storing/bcrypt"
   end
 
-  def self.authenticate(request, methods = Doorkeeper.config.access_token_methods)
-    OAuth::Token.authenticate(request, *methods)
-  end
+  class << self
+    attr_reader :orm_adapter
+
+    def configure(&block)
+      @config = Config::Builder.new(&block).build
+      setup
+      @config
+    end
+
+    # @return [Doorkeeper::Config] configuration instance
+    #
+    def configuration
+      @config || configure
+    end
+
+    def configured?
+      !@config.nil?
+    end
+
+    alias config configuration
+
+    def setup
+      setup_orm_adapter
+      run_orm_hooks
+      config.clear_cache!
+
+      # Deprecated, will be removed soon
+      unless configuration.orm == :active_record
+        setup_orm_models
+        setup_application_owner
+      end
+    end
+
+    def setup_orm_adapter
+      @orm_adapter = "doorkeeper/orm/#{configuration.orm}".classify.constantize
+    rescue NameError => e
+      raise e, "ORM adapter not found (#{configuration.orm})", <<-ERROR_MSG.strip_heredoc
+        [DOORKEEPER] ORM adapter not found (#{configuration.orm}), or there was an error
+        trying to load it.
 
-  def self.gem_version
-    ::Gem::Version.new(::Doorkeeper::VERSION::STRING)
+        You probably need to add the related gem for this adapter to work with
+        doorkeeper.
+      ERROR_MSG
+    end
+
+    def run_orm_hooks
+      if @orm_adapter.respond_to?(:run_hooks)
+        @orm_adapter.run_hooks
+      else
+        ::Kernel.warn <<~MSG.strip_heredoc
+          [DOORKEEPER] ORM "#{configuration.orm}" should move all it's setup logic under `#run_hooks` method for
+          the #{@orm_adapter.name}. Later versions of Doorkeeper will no longer support `setup_orm_models` and
+          `setup_application_owner` API.
+        MSG
+      end
+    end
+
+    def setup_orm_models
+      @orm_adapter.initialize_models!
+    end
+
+    def setup_application_owner
+      @orm_adapter.initialize_application_owner!
+    end
+
+    def authenticate(request, methods = Doorkeeper.config.access_token_methods)
+      OAuth::Token.authenticate(request, *methods)
+    end
+
+    def gem_version
+      ::Gem::Version.new(::Doorkeeper::VERSION::STRING)
+    end
   end
 end

lib/doorkeeper/config.rb

@@ -5,87 +5,11 @@
 require "doorkeeper/config/validations"
 
 module Doorkeeper
-  # Defines a MissingConfiguration error for a missing Doorkeeper configuration
-  #
-  class MissingConfiguration < StandardError
-    def initialize
-      super("Configuration for doorkeeper missing. Do you have doorkeeper initializer?")
-    end
-  end
-
   # Doorkeeper option DSL could be reused in extensions to build their own
   # configurations. To use the Option DSL gems need to define `builder_class` method
   # that returns configuration Builder class. This exception raises when they don't
   # define it.
   #
-  class MissingConfigurationBuilderClass < StandardError; end
-
-  class << self
-    attr_reader :orm_adapter
-
-    def configure(&block)
-      @config = Config::Builder.new(&block).build
-      setup
-      @config
-    end
-
-    # @return [Doorkeeper::Config] configuration instance
-    #
-    def configuration
-      @config || (raise MissingConfiguration)
-    end
-
-    def configured?
-      !@config.nil?
-    end
-
-    alias config configuration
-
-    def setup
-      setup_orm_adapter
-      run_orm_hooks
-      config.clear_cache!
-
-      # Deprecated, will be removed soon
-      unless configuration.orm == :active_record
-        setup_orm_models
-        setup_application_owner
-      end
-    end
-
-    def setup_orm_adapter
-      @orm_adapter = "doorkeeper/orm/#{configuration.orm}".classify.constantize
-    rescue NameError => e
-      raise e, "ORM adapter not found (#{configuration.orm})", <<-ERROR_MSG.strip_heredoc
-        [DOORKEEPER] ORM adapter not found (#{configuration.orm}), or there was an error
-        trying to load it.
-
-        You probably need to add the related gem for this adapter to work with
-        doorkeeper.
-      ERROR_MSG
-    end
-
-    def run_orm_hooks
-      if @orm_adapter.respond_to?(:run_hooks)
-        @orm_adapter.run_hooks
-      else
-        ::Kernel.warn <<~MSG.strip_heredoc
-          [DOORKEEPER] ORM "#{configuration.orm}" should move all it's setup logic under `#run_hooks` method for
-          the #{@orm_adapter.name}. Later versions of Doorkeeper will no longer support `setup_orm_models` and
-          `setup_application_owner` API.
-        MSG
-      end
-    end
-
-    def setup_orm_models
-      @orm_adapter.initialize_models!
-    end
-
-    def setup_application_owner
-      @orm_adapter.initialize_application_owner!
-    end
-  end
-
   class Config
     # Default Doorkeeper configuration builder
     class Builder < AbstractBuilder

lib/doorkeeper/config/abstract_builder.rb

@@ -12,7 +12,7 @@ class AbstractBuilder
       #
       def initialize(config = Config.new, &block)
         @config = config
-        instance_eval(&block)
+        instance_eval(&block) if block_given?
       end
 
       # Builds and validates configuration.

spec/lib/config_spec.rb

@@ -501,21 +501,6 @@ class ApplicationWithOwner < ActiveRecord::Base
     end
   end
 
-  it "raises an exception when configuration is not set" do
-    old_config = Doorkeeper.config
-    Doorkeeper.module_eval do
-      @config = nil
-    end
-
-    expect do
-      Doorkeeper.config
-    end.to raise_error Doorkeeper::MissingConfiguration
-
-    Doorkeeper.module_eval do
-      @config = old_config
-    end
-  end
-
   describe "access_token_generator" do
     it "is 'Doorkeeper::OAuth::Helpers::UniqueToken' by default" do
       expect(Doorkeeper.configuration.access_token_generator).to(