Remove hard coded references to Active Record in railties

activerecord/lib/active_record/connection_adapters/connection_specification.rb

@@ -38,7 +38,7 @@ def spec
         private
         def resolve_string_connection(spec) # :nodoc:
           hash = configurations.fetch(spec) do |k|
-            self.class.connection_url_to_hash(k)
+            connection_url_to_hash(k)
           end
 
           raise(AdapterNotSpecified, "#{spec} database is not configured") unless hash
@@ -65,7 +65,7 @@ def resolve_hash_connection(spec) # :nodoc:
           ConnectionSpecification.new(spec, adapter_method)
         end
 
-        def self.connection_url_to_hash(url) # :nodoc:
+        def connection_url_to_hash(url) # :nodoc:
           config = URI.parse url
           adapter = config.scheme
           adapter = "postgresql" if adapter == "postgres"

activerecord/lib/active_record/railtie.rb

@@ -152,7 +152,7 @@ class Railtie < Rails::Railtie # :nodoc:
     # and then establishes the connection.
     initializer "active_record.initialize_database" do |app|
       ActiveSupport.on_load(:active_record) do
-        self.configurations = app.config.database_configuration
+        self.configurations = app.config.database_configuration || {}
         establish_connection
       end
     end

activerecord/lib/active_record/railties/databases.rake

@@ -2,7 +2,7 @@ require 'active_record'
 
 db_namespace = namespace :db do
   task :load_config do
-    ActiveRecord::Base.configurations = Rails.application.config.database_configuration
+    ActiveRecord::Base.configurations = Rails.application.config.database_configuration || {}
     ActiveRecord::Migrator.migrations_paths = Rails.application.paths['db/migrate'].to_a
 
     if defined?(ENGINE_PATH) && engine = Rails::Engine.find(ENGINE_PATH)

railties/lib/rails/application/configuration.rb

@@ -98,14 +98,15 @@ def threadsafe!
       end
 
       # Loads and returns the configuration of the database.
-      # First, looks at If ENV['DATABASE_URL'] if it's not present it uses the #paths["config/database"]
-      # The contents of the file are processed via ERB before being sent through YAML::load. 
       def database_configuration
-        if ENV['DATABASE_URL']
-          {Rails.env => ActiveRecord::ConnectionAdapters::ConnectionSpecification::Resolver.connection_url_to_hash(ENV['DATABASE_URL']).stringify_keys}
+        yaml = paths["config/database"].first
+        if File.exists?(yaml)
+          require "erb"
+          YAML.load ERB.new(IO.read(yaml)).result
+        elsif ENV['DATABASE_URL']
+          nil
         else
-          require 'erb'
-          YAML.load ERB.new(IO.read(paths["config/database"].first)).result
+          raise "Could not load database configuration. No such file - #{yaml}"
         end
       rescue Psych::SyntaxError => e
         raise "YAML syntax error occurred while parsing #{paths["config/database"].first}. " \

railties/test/application/rake/dbs_test.rb

@@ -166,19 +166,6 @@ def db_test_load_structure
         require "#{app_path}/config/environment"
         db_test_load_structure
       end
-
-      test 'db:test:load_structure with database_url' do
-        old_rails_env = ENV["RAILS_ENV"]
-        ENV["RAILS_ENV"] = 'test'
-
-        begin
-          require "#{app_path}/config/environment"
-          set_database_url
-          db_test_load_structure
-        ensure
-          ENV["RAILS_ENV"] = old_rails_env
-        end
-      end
     end
   end
 end