remove uninitialised variable warnings

lib/database_cleaner/active_record/base.rb

@@ -28,7 +28,7 @@ module DatabaseCleaner
       end
 
       def db
-        @db || super
+        @db ||= super
       end
 
       def load_config
@@ -39,8 +39,8 @@ module DatabaseCleaner
       end
 
       def connection_class
-        @connection_class ||= if @db && !@db.is_a?(Symbol)
-                                @db
+        @connection_class ||= if db && !db.is_a?(Symbol)
+                                db
                               elsif connection_hash
                                 lookup_from_connection_pool || establish_connection
                               else

lib/database_cleaner/base.rb

@@ -25,7 +25,7 @@ module DatabaseCleaner
     end
 
     def db
-      @db || :default
+      @db ||= :default
     end
 
     def create_strategy(*args)
@@ -67,7 +67,7 @@ module DatabaseCleaner
     end
 
     def strategy
-      @strategy || NullStrategy
+      @strategy ||= NullStrategy
     end
 
     def orm=(desired_orm)

lib/database_cleaner/configuration.rb

@@ -37,7 +37,7 @@ module DatabaseCleaner
     end
 
     def app_root
-      @app_root || Dir.pwd
+      @app_root ||= Dir.pwd
     end
 
     def connections

lib/database_cleaner/data_mapper/base.rb

@@ -13,7 +13,7 @@ module DatabaseCleaner
       end
 
       def db
-        @db || :default
+        @db ||= :default
       end
 
     end

lib/database_cleaner/mongo_mapper/base.rb

@@ -13,7 +13,7 @@ module DatabaseCleaner
       end
 
       def db
-        @db || :default
+        @db ||= :default
       end
     end
   end

lib/database_cleaner/moped/base.rb

@@ -14,7 +14,7 @@ module DatabaseCleaner
       end
 
       def db
-        @db || :default
+        @db ||= :default
       end
 
       def host_port=(desired_host)
@@ -22,7 +22,7 @@ module DatabaseCleaner
       end
 
       def host
-        @host || '127.0.0.1:27017'
+        @host ||= '127.0.0.1:27017'
       end
 
       private

lib/database_cleaner/redis/base.rb

@@ -14,7 +14,7 @@ module DatabaseCleaner
       end
 
       def db
-        @db || :default
+        @db ||= :default
       end
 
       alias url db

spec/database_cleaner/moped/truncation_spec.rb

@@ -8,7 +8,7 @@ module DatabaseCleaner
 
     describe Truncation do
       let(:args) {{}}
-      let(:truncation) { described_class.new(args).tap { |t| t.db=@db } }
+      let(:truncation) { described_class.new(args) }
       #doing this in the file root breaks autospec, doing it before(:all) just fails the specs
       before(:all) do
         @test_db = 'database_cleaner_specs'