Added protection against duplicate migration names (Aslak Hellesøy) [#112 state:resolved]

activerecord/CHANGELOG

@@ -1,5 +1,7 @@
 *SVN*
 
+* Added protection against duplicate migration names (Aslak Hellesøy) [#112]
+
 * Base#instantiate_time_object: eliminate check for Time.zone, since we can assume this is set if time_zone_aware_attributes is set to true [Geoff Buesing]
 
 * Time zone aware attribute methods use Time.zone.parse instead of #to_time for String arguments, so that offset information in String is respected. Resolves #105. [Scott Fleckenstein, Geoff Buesing]

activerecord/lib/active_record/migration.rb

@@ -8,6 +8,12 @@ module ActiveRecord
     end
   end
 
+  class DuplicateMigrationNameError < ActiveRecordError#:nodoc:
+    def initialize(name)
+      super("Multiple migrations have the name #{name}")
+    end
+  end
+
   class UnknownMigrationVersionError < ActiveRecordError #:nodoc:
     def initialize(version)
       super("No migration with version number #{version}")
@@ -441,6 +447,10 @@ module ActiveRecord
             raise DuplicateMigrationVersionError.new(version) 
           end
 
+          if klasses.detect { |m| m.name == name.camelize }
+            raise DuplicateMigrationNameError.new(name.camelize) 
+          end
+          
           load(file)
           
           klasses << returning(name.camelize.constantize) do |klass|

activerecord/test/cases/migration_test.rb

@@ -984,6 +984,12 @@ if ActiveRecord::Base.connection.supports_migrations?
       end
     end
 
+    def test_migrator_with_duplicate_names
+      assert_raises(ActiveRecord::DuplicateMigrationNameError, "Multiple migrations have the name Chunky") do
+        ActiveRecord::Migrator.migrate(MIGRATIONS_ROOT + "/duplicate_names", nil)
+      end
+    end
+
     def test_migrator_with_missing_version_numbers
       assert_raise(ActiveRecord::UnknownMigrationVersionError) do
         ActiveRecord::Migrator.migrate(MIGRATIONS_ROOT + "/missing", 500)

activerecord/test/migrations/duplicate_names/20080507052938_chunky.rb

@@ -0,0 +1,7 @@
+class Chunky < ActiveRecord::Migration
+  def self.up
+  end
+
+  def self.down
+  end
+end

activerecord/test/migrations/duplicate_names/20080507053028_chunky.rb

@@ -0,0 +1,7 @@
+class Chunky < ActiveRecord::Migration
+  def self.up
+  end
+
+  def self.down
+  end
+end