truncation AR strategy now takes :only and :except so you can manage the tables you want to truncate

lib/database_cleaner/active_record/truncation.rb

@@ -2,7 +2,7 @@
 module ActiveRecord
   module ConnectionAdapters
     class MysqlAdapter
-      def truncate_tabe(table_name)
+      def truncate_table(table_name)
         execute("TRUNCATE TABLE #{table_name};")
       end
     end
@@ -21,6 +21,18 @@ end
 module DatabaseCleaner::ActiveRecord
   class Truncation
 
+    def initialize(options={})
+      if !options.empty? && !(options.keys - [:only, :except]).empty?
+        raise ArgumentError, "The only valid options are :only and :except. You specified #{options.keys.join(',')}."
+      end
+      if options.has_key?(:only) && options.has_key?(:except)
+        raise ArgumentError, "You may only specify either :only or :either.  Doing both doesn't really make sense does it?" 
+      end
+
+      @only = options[:only]
+      @tables_to_exclude = (options[:except] || []) << 'schema_migrations'
+    end
+
     def start
       # no-op
     end
@@ -28,7 +40,7 @@ module DatabaseCleaner::ActiveRecord
 
     def clean
       connection.disable_referential_integrity do
-        (connection.tables - %w{schema_migrations}).each do |table_name|
+        tables_to_truncate.each do |table_name|
           connection.truncate_table table_name
         end
       end
@@ -36,8 +48,12 @@ module DatabaseCleaner::ActiveRecord
 
   private
 
+    def tables_to_truncate
+      (@only || connection.tables) - @tables_to_exclude
+    end
+
     def connection
-      ActiveRecord::Base.connection
+      ::ActiveRecord::Base.connection
     end
 
   end

spec/database_cleaner/active_record/truncation_spec.rb

@@ -0,0 +1,66 @@
+require File.dirname(__FILE__) + '/../../spec_helper'
+require 'database_cleaner/active_record/truncation'
+require 'active_record'
+#module ActiveRecord
+  #module ConnectionAdapters
+    #[MysqlAdapter, SQLite3Adapter].each do |adapter|
+      #describe adapter, "#truncate_table" do
+        #it "should truncate the table"
+      #end
+    #end
+  #end
+#end
+
+module DatabaseCleaner
+  module ActiveRecord
+    
+    describe Truncation do
+      before(:each) do
+        @connection = mock('connection')
+        @connection.stub!(:disable_referential_integrity).and_yield
+        ::ActiveRecord::Base.stub!(:connection).and_return(@connection)
+      end
+
+      it "should truncate all tables except for schema_migrations" do
+        @connection.stub!(:tables).and_return(%w[schema_migrations widgets dogs])
+
+        @connection.should_receive(:truncate_table).with('widgets')
+        @connection.should_receive(:truncate_table).with('dogs')
+        @connection.should_not_receive(:truncate_table).with('schema_migrations')
+
+        Truncation.new.clean
+      end
+
+      it "should only truncate the tables specified in the :only option when provided" do
+        @connection.stub!(:tables).and_return(%w[schema_migrations widgets dogs])
+
+        @connection.should_receive(:truncate_table).with('widgets')
+        @connection.should_not_receive(:truncate_table).with('dogs')
+
+        Truncation.new(:only => ['widgets']).clean
+      end
+
+      it "should not truncate the tables specified in the :except option" do
+        @connection.stub!(:tables).and_return(%w[schema_migrations widgets dogs])
+
+        @connection.should_receive(:truncate_table).with('dogs')
+        @connection.should_not_receive(:truncate_table).with('widgets')
+
+        Truncation.new(:except => ['widgets']).clean
+      end
+
+      it "should raise an error when :only and :except options are used" do
+        running { 
+          Truncation.new(:except => ['widgets'], :only => ['widgets'])
+        }.should raise_error(ArgumentError)
+      end
+
+      it "should raise an error when invalid options are provided" do
+        running { Truncation.new(:foo => 'bar') }.should raise_error(ArgumentError)
+      end
+
+
+    end
+
+  end
+end

spec/database_cleaner/configuration_spec.rb

@@ -3,6 +3,16 @@ require 'database_cleaner/active_record/transaction'
 require 'database_cleaner/data_mapper/transaction'
 
 describe DatabaseCleaner do
+
+  # These examples muck around with the constants for autodetection so we need to clean up....
+  before(:all) do
+    TempAR = ActiveRecord unless defined?(TempAR)
+    # need to add one for each ORM that we load in the spec helper...
+  end
+  after(:all) do
+    ActiveRecord = TempAR
+  end
+
   before(:each) do
     DatabaseCleaner::ActiveRecord::Transaction.stub!(:new).and_return(@strategy = mock('strategy'))
     Object.const_set('ActiveRecord', "just mocking out the constant here...") unless defined?(::ActiveRecord)
@@ -64,4 +74,5 @@ describe DatabaseCleaner do
         end
       end
     end
+
 end

spec/spec.opts

@@ -3,3 +3,4 @@
 --loadby
 mtime
 --reverse
+--backtrace

spec/spec_helper.rb

@@ -1,5 +1,6 @@
 require 'rubygems'
 require 'spec'
+require 'activerecord'
 
 $:.unshift(File.dirname(__FILE__) + '/../lib')
 require 'database_cleaner'