fixed support for DATABASE_URL for rake db tasks

- added tests to confirm establish_connection uses DATABASE_URL and
  Rails.env correctly even when no arguments are passed in.
- updated rake db tasks to support DATABASE_URL, and added tests to
  confirm correct behavior for these rake tasks.  (Removed
  establish_connection call from some tasks since in those cases
  the :environment task already made sure the function would be called)
- updated Resolver so that when it resolves the database url, it
  removes hash values with empty strings from the config spec (e.g.
  to support connection to postgresql when no username is specified).

4 files changed, 60 insertions, 32 deletions

diff --git a/activerecord/lib/active_record/connection_adapters/connection_specification.rb b/activerecord/lib/active_record/connection_adapters/connection_specification.rb
index dd40351a38..b9a61f7d91 100644
--- a/activerecord/lib/active_record/connection_adapters/connection_specification.rb
+++ b/activerecord/lib/active_record/connection_adapters/connection_specification.rb
@@ -72,7 +72,7 @@ module ActiveRecord
                    :port     => config.port,
                    :database => config.path.sub(%r{^/},""),
                    :host     => config.host }
-          spec.reject!{ |_,value| !value }
+          spec.reject!{ |_,value| value.blank? }
           if config.query
             options = Hash[config.query.split("&").map{ |pair| pair.split("=") }].symbolize_keys
             spec.merge!(options)
diff --git a/activerecord/lib/active_record/railties/databases.rake b/activerecord/lib/active_record/railties/databases.rake
index ae24542521..bcb26f72c8 100644
--- a/activerecord/lib/active_record/railties/databases.rake
+++ b/activerecord/lib/active_record/railties/databases.rake
@@ -18,9 +18,13 @@ db_namespace = namespace :db do
     end
   end
 
-  desc 'Create the database from config/database.yml for the current Rails.env (use db:create:all to create all dbs in the config)'
+  desc 'Create the database from DATABASE_URL or config/database.yml for the current Rails.env (use db:create:all to create all dbs in the config)'
   task :create => [:load_config] do
-    ActiveRecord::Tasks::DatabaseTasks.create_current
+    if ENV['DATABASE_URL']
+      ActiveRecord::Tasks::DatabaseTasks.create_database_url
+    else
+      ActiveRecord::Tasks::DatabaseTasks.create_current
+    end
   end
 
   namespace :drop do
@@ -29,9 +33,13 @@ db_namespace = namespace :db do
     end
   end
 
-  desc 'Drops the database for the current Rails.env (use db:drop:all to drop all databases)'
+  desc 'Drops the database using DATABASE_URL or the current Rails.env (use db:drop:all to drop all databases)'
   task :drop => [:load_config] do
-    ActiveRecord::Tasks::DatabaseTasks.drop_current
+    if ENV['DATABASE_URL']
+      ActiveRecord::Tasks::DatabaseTasks.drop_database_url
+    else
+      ActiveRecord::Tasks::DatabaseTasks.drop_current
+    end
   end
 
   desc "Migrate the database (options: VERSION=x, VERBOSE=false, SCOPE=blog)."
@@ -88,8 +96,6 @@ db_namespace = namespace :db do
 
     desc 'Display status of migrations'
     task :status => [:environment, :load_config] do
-      config = ActiveRecord::Base.configurations[Rails.env]
-      ActiveRecord::Base.establish_connection(config)
       unless ActiveRecord::Base.connection.table_exists?(ActiveRecord::Migrator.schema_migrations_table_name)
         puts 'Schema migrations table does not exist yet.'
         next  # means "return" for rake task
@@ -110,7 +116,7 @@ db_namespace = namespace :db do
         ['up', version, '********** NO FILE **********']
       end
       # output
-      puts "\ndatabase: #{config['database']}\n\n"
+      puts "\ndatabase: #{ActiveRecord::Base.connection_config[:database]}\n\n"
       puts "#{'Status'.center(8)}  #{'Migration ID'.ljust(14)}  Migration Name"
       puts "-" * 50
       (db_list + file_list).sort_by {|migration| migration[1]}.each do |migration|
@@ -186,7 +192,6 @@ db_namespace = namespace :db do
     task :load => [:environment, :load_config] do
       require 'active_record/fixtures'
 
-      ActiveRecord::Base.establish_connection(Rails.env)
       base_dir     = File.join [Rails.root, ENV['FIXTURES_PATH'] || %w{test fixtures}].flatten
       fixtures_dir = File.join [base_dir, ENV['FIXTURES_DIR']].compact
 
@@ -225,7 +230,6 @@ db_namespace = namespace :db do
       require 'active_record/schema_dumper'
       filename = ENV['SCHEMA'] || "#{Rails.root}/db/schema.rb"
       File.open(filename, "w:utf-8") do |file|
-        ActiveRecord::Base.establish_connection(Rails.env)
         ActiveRecord::SchemaDumper.dump(ActiveRecord::Base.connection, file)
       end
       db_namespace['schema:dump'].reenable
@@ -277,22 +281,22 @@ db_namespace = namespace :db do
 
     desc 'Dump the database structure to db/structure.sql. Specify another file with DB_STRUCTURE=db/my_structure.sql'
     task :dump => [:environment, :load_config] do
-      abcs = ActiveRecord::Base.configurations
       filename = ENV['DB_STRUCTURE'] || File.join(Rails.root, "db", "structure.sql")
-      case abcs[Rails.env]['adapter']
+      current_config = ActiveRecord::Tasks::DatabaseTasks.current_config
+      case current_config['adapter']
       when /mysql/, /postgresql/, /sqlite/
-        ActiveRecord::Tasks::DatabaseTasks.structure_dump(abcs[Rails.env], filename)
+        ActiveRecord::Tasks::DatabaseTasks.structure_dump(current_config, filename)
       when 'oci', 'oracle'
-        ActiveRecord::Base.establish_connection(abcs[Rails.env])
+        ActiveRecord::Base.establish_connection(current_config)
         File.open(filename, "w:utf-8") { |f| f << ActiveRecord::Base.connection.structure_dump }
       when 'sqlserver'
-        `smoscript -s #{abcs[Rails.env]['host']} -d #{abcs[Rails.env]['database']} -u #{abcs[Rails.env]['username']} -p #{abcs[Rails.env]['password']} -f #{filename} -A -U`
+        `smoscript -s #{current_config['host']} -d #{current_config['database']} -u #{current_config['username']} -p #{current_config['password']} -f #{filename} -A -U`
       when "firebird"
-        set_firebird_env(abcs[Rails.env])
-        db_string = firebird_db_string(abcs[Rails.env])
+        set_firebird_env(current_config)
+        db_string = firebird_db_string(current_config)
         sh "isql -a #{db_string} > #{filename}"
       else
-        raise "Task not supported by '#{abcs[Rails.env]["adapter"]}'"
+        raise "Task not supported by '#{current_config["adapter"]}'"
       end
 
       if ActiveRecord::Base.connection.supports_migrations?
@@ -303,26 +307,24 @@ db_namespace = namespace :db do
 
     # desc "Recreate the databases from the structure.sql file"
     task :load => [:environment, :load_config] do
-      env = ENV['RAILS_ENV'] || 'test'
-
-      abcs = ActiveRecord::Base.configurations
+      current_config = ActiveRecord::Tasks::DatabaseTasks.current_config(:env => (ENV['RAILS_ENV'] || 'test'))
       filename = ENV['DB_STRUCTURE'] || File.join(Rails.root, "db", "structure.sql")
-      case abcs[env]['adapter']
+      case current_config['adapter']
       when /mysql/, /postgresql/, /sqlite/
-        ActiveRecord::Tasks::DatabaseTasks.structure_load(abcs[env], filename)
+        ActiveRecord::Tasks::DatabaseTasks.structure_load(current_config, filename)
       when 'sqlserver'
-        `sqlcmd -S #{abcs[env]['host']} -d #{abcs[env]['database']} -U #{abcs[env]['username']} -P #{abcs[env]['password']} -i #{filename}`
+        `sqlcmd -S #{current_config['host']} -d #{current_config['database']} -U #{current_config['username']} -P #{current_config['password']} -i #{filename}`
       when 'oci', 'oracle'
-        ActiveRecord::Base.establish_connection(abcs[env])
+        ActiveRecord::Base.establish_connection(current_config)
         IO.read(filename).split(";\n\n").each do |ddl|
           ActiveRecord::Base.connection.execute(ddl)
         end
       when 'firebird'
-        set_firebird_env(abcs[env])
-        db_string = firebird_db_string(abcs[env])
+        set_firebird_env(current_config)
+        db_string = firebird_db_string(current_config)
         sh "isql -i #{filename} #{db_string}"
       else
-        raise "Task not supported by '#{abcs[env]['adapter']}'"
+        raise "Task not supported by '#{current_config['adapter']}'"
       end
     end
 
@@ -353,10 +355,10 @@ db_namespace = namespace :db do
     # desc "Recreate the test database from an existent structure.sql file"
     task :load_structure => 'db:test:purge' do
       begin
-        old_env, ENV['RAILS_ENV'] = ENV['RAILS_ENV'], 'test'
+        ActiveRecord::Tasks::DatabaseTasks.current_config(:config => ActiveRecord::Base.configurations['test'])
         db_namespace["structure:load"].invoke
       ensure
-        ENV['RAILS_ENV'] = old_env
+        ActiveRecord::Tasks::DatabaseTasks.current_config(:config => nil)
       end
     end
 
diff --git a/activerecord/lib/active_record/tasks/database_tasks.rb b/activerecord/lib/active_record/tasks/database_tasks.rb
index b41cc68b6a..fda51b3d76 100644
--- a/activerecord/lib/active_record/tasks/database_tasks.rb
+++ b/activerecord/lib/active_record/tasks/database_tasks.rb
@@ -3,6 +3,8 @@ module ActiveRecord
     module DatabaseTasks # :nodoc:
       extend self
 
+      attr_writer :current_config
+
       LOCAL_HOSTS    = ['127.0.0.1', 'localhost']
 
       def register_task(pattern, task)
@@ -14,6 +16,19 @@ module ActiveRecord
       register_task(/postgresql/, ActiveRecord::Tasks::PostgreSQLDatabaseTasks)
       register_task(/sqlite/, ActiveRecord::Tasks::SQLiteDatabaseTasks)
 
+      def current_config(options = {})
+        options.reverse_merge! :env => Rails.env
+        if options.has_key?(:config)
+          @current_config = options[:config]
+        else
+          @current_config ||= if ENV['DATABASE_URL']
+                                database_url_config
+                              else
+                                ActiveRecord::Base.configurations[options[:env]]
+                              end
+        end
+      end
+
       def create(*arguments)
         configuration = arguments.first
         class_for_adapter(configuration['adapter']).new(*arguments).create
@@ -33,6 +48,10 @@ module ActiveRecord
         ActiveRecord::Base.establish_connection environment
       end
 
+      def create_database_url
+        create database_url_config
+      end
+
       def drop(*arguments)
         configuration = arguments.first
         class_for_adapter(configuration['adapter']).new(*arguments).drop
@@ -51,6 +70,10 @@ module ActiveRecord
         }
       end
 
+      def drop_database_url
+        drop database_url_config
+      end
+
       def charset_current(environment = Rails.env)
         charset ActiveRecord::Base.configurations[environment]
       end
@@ -87,6 +110,11 @@ module ActiveRecord
 
       private
 
+      def database_url_config
+        @database_url_config ||=
+               ConnectionAdapters::ConnectionSpecification::Resolver.new(ENV["DATABASE_URL"], {}).spec.config.stringify_keys
+      end
+
       def class_for_adapter(adapter)
         key = @tasks.keys.detect { |pattern| adapter[pattern] }
         @tasks[key]
diff --git a/activerecord/test/cases/connection_specification/resolver_test.rb b/activerecord/test/cases/connection_specification/resolver_test.rb
index 673a2b2b88..434d2b7ba5 100644
--- a/activerecord/test/cases/connection_specification/resolver_test.rb
+++ b/activerecord/test/cases/connection_specification/resolver_test.rb
@@ -13,7 +13,6 @@ module ActiveRecord
           spec = resolve 'mysql://foo?encoding=utf8'
           assert_equal({
             :adapter  => "mysql",
-            :database => "",
             :host     => "foo",
             :encoding => "utf8" }, spec)
         end
@@ -33,7 +32,6 @@ module ActiveRecord
           spec = resolve 'mysql://foo:123?encoding=utf8'
           assert_equal({
             :adapter  => "mysql",
-            :database => "",
             :port     => 123,
             :host     => "foo",
             :encoding => "utf8" }, spec)