Moves column dump specific code to a module included in AbstractAdapter

Having column related schema dumper code in the AbstractAdapter. The
code remains the same, but by placing it in the AbstractAdapter, we can
then overwrite it with Adapter specific methods that will help with
Adapter specific data types.

The goal of moving this code here is to create a new migration key for
PostgreSQL's array type. Since any datatype can be an array, the goal is
to have ':array => true' as a migration option, turning the datatype
into an array. I've implemented this in postgres_ext, the syntax is
shown here: https://github.com/dockyard/postgres_ext#arrays

Adds array migration support

Adds array_test.rb outlining the test cases for array data type
Adds pg_array_parser to Gemfile for testing
Adds pg_array_parser to postgresql_adapter (unused in this commit)

Adds schema dump support for arrays

Adds postgres array type casting support

Updates changelog, adds note for inet and cidr support, which I forgot to add before

Removing debugger, Adds pg_array_parser to JRuby platform

Removes pg_array_parser requirement, creates ArrayParser module used by
PostgreSQLAdapter

3 files changed, 115 insertions, 9 deletions

diff --git a/activerecord/test/cases/adapters/postgresql/array_test.rb b/activerecord/test/cases/adapters/postgresql/array_test.rb
new file mode 100644
index 0000000000..8774bf626f
--- /dev/null
+++ b/activerecord/test/cases/adapters/postgresql/array_test.rb
@@ -0,0 +1,98 @@
+# encoding: utf-8
+require "cases/helper"
+require 'active_record/base'
+require 'active_record/connection_adapters/postgresql_adapter'
+
+class PostgresqlArrayTest < ActiveRecord::TestCase
+  class PgArray < ActiveRecord::Base
+    self.table_name = 'pg_arrays'
+  end
+
+  def setup
+    @connection = ActiveRecord::Base.connection
+      @connection.transaction do
+        @connection.create_table('pg_arrays') do |t|
+          t.string 'tags', :array => true
+        end
+      end
+    @column = PgArray.columns.find { |c| c.name == 'tags' }
+  end
+
+  def teardown
+    @connection.execute 'drop table if exists pg_arrays'
+  end
+
+  def test_column
+    assert_equal :string, @column.type
+    assert @column.array
+  end
+
+  def test_type_cast_array
+    assert @column
+
+    data = '{1,2,3}'
+    oid_type  = @column.instance_variable_get('@oid_type').subtype
+    # we are getting the instance variable in this test, but in the
+    # normal use of string_to_array, it's called from the OID::Array
+    # class and will have the OID instance that will provide the type
+    # casting
+    array = @column.class.string_to_array data, oid_type
+    assert_equal(['1', '2', '3'], array)
+    assert_equal(['1', '2', '3'], @column.type_cast(data))
+
+    assert_equal([], @column.type_cast('{}'))
+    assert_equal([nil], @column.type_cast('{NULL}'))
+  end
+
+  def test_rewrite
+    @connection.execute "insert into pg_arrays (tags) VALUES ('{1,2,3}')"
+    x = PgArray.first
+    x.tags = ['1','2','3','4']
+    assert x.save!
+  end
+
+  def test_select
+    @connection.execute "insert into pg_arrays (tags) VALUES ('{1,2,3}')"
+    x = PgArray.first
+    assert_equal(['1','2','3'], x.tags)
+  end
+
+  def test_multi_dimensional
+    assert_cycle([['1','2'],['2','3']])
+  end
+
+  def test_strings_with_quotes
+    assert_cycle(['this has','some "s that need to be escaped"'])
+  end
+
+  def test_strings_with_commas
+    assert_cycle(['this,has','many,values'])
+  end
+
+  def test_strings_with_array_delimiters
+    assert_cycle(['{','}'])
+  end
+
+  def test_strings_with_null_strings
+    assert_cycle(['NULL','NULL'])
+  end
+
+  def test_contains_nils
+    assert_cycle(['1',nil,nil])
+  end
+
+  private
+  def assert_cycle array
+    # test creation
+    x = PgArray.create!(:tags => array)
+    x.reload
+    assert_equal(array, x.tags)
+
+    # test updating
+    x = PgArray.create!(:tags => [])
+    x.tags = array
+    x.save!
+    x.reload
+    assert_equal(array, x.tags)
+  end
+end
diff --git a/activerecord/test/cases/adapters/postgresql/datatype_test.rb b/activerecord/test/cases/adapters/postgresql/datatype_test.rb
index a7f6d9c580..c7ce43d71e 100644
--- a/activerecord/test/cases/adapters/postgresql/datatype_test.rb
+++ b/activerecord/test/cases/adapters/postgresql/datatype_test.rb
@@ -70,8 +70,8 @@ class PostgresqlDataTypeTest < ActiveRecord::TestCase
   end
 
   def test_data_type_of_array_types
-    assert_equal :string, @first_array.column_for_attribute(:commission_by_quarter).type
-    assert_equal :string, @first_array.column_for_attribute(:nicknames).type
+    assert_equal :integer, @first_array.column_for_attribute(:commission_by_quarter).type
+    assert_equal :text, @first_array.column_for_attribute(:nicknames).type
   end
 
   def test_data_type_of_tsvector_types
@@ -112,8 +112,8 @@ class PostgresqlDataTypeTest < ActiveRecord::TestCase
   end
 
   def test_array_values
-   assert_equal '{35000,21000,18000,17000}', @first_array.commission_by_quarter
-   assert_equal '{foo,bar,baz}', @first_array.nicknames
+   assert_equal [35000,21000,18000,17000], @first_array.commission_by_quarter
+   assert_equal ['foo','bar','baz'], @first_array.nicknames
   end
 
   def test_tsvector_values
@@ -170,7 +170,7 @@ class PostgresqlDataTypeTest < ActiveRecord::TestCase
   end
 
   def test_update_integer_array
-    new_value = '{32800,95000,29350,17000}'
+    new_value = [32800,95000,29350,17000]
     assert @first_array.commission_by_quarter = new_value
     assert @first_array.save
     assert @first_array.reload
@@ -182,7 +182,7 @@ class PostgresqlDataTypeTest < ActiveRecord::TestCase
   end
 
   def test_update_text_array
-    new_value = '{robby,robert,rob,robbie}'
+    new_value = ['robby','robert','rob','robbie']
     assert @first_array.nicknames = new_value
     assert @first_array.save
     assert @first_array.reload
diff --git a/activerecord/test/cases/schema_dumper_test.rb b/activerecord/test/cases/schema_dumper_test.rb
index 80d2670f94..80f46c6b08 100644
--- a/activerecord/test/cases/schema_dumper_test.rb
+++ b/activerecord/test/cases/schema_dumper_test.rb
@@ -79,9 +79,9 @@ class SchemaDumperTest < ActiveRecord::TestCase
 
   def test_arguments_line_up
     column_definition_lines.each do |column_set|
-      assert_line_up(column_set, /:default => /)
-      assert_line_up(column_set, /:limit => /)
-      assert_line_up(column_set, /:null => /)
+      assert_line_up(column_set, /default: /)
+      assert_line_up(column_set, /limit: /)
+      assert_line_up(column_set, /null: /)
     end
   end
 
@@ -278,6 +278,14 @@ class SchemaDumperTest < ActiveRecord::TestCase
       end
     end
 
+    def test_schema_dump_includes_arrays_shorthand_definition
+      output = standard_dump
+      if %r{create_table "postgresql_arrays"} =~ output
+        assert_match %r[t.text\s+"nicknames",\s+array: true], output
+        assert_match %r[t.integer\s+"commission_by_quarter",\s+array: true], output
+      end
+    end
+
     def test_schema_dump_includes_tsvector_shorthand_definition
       output = standard_dump
       if %r{create_table "postgresql_tsvectors"} =~ output