Add Expression Indexes and Operator Classes support for PostgreSQL

Example:

    create_table :users do |t|
      t.string :name
      t.index 'lower(name) varchar_pattern_ops'
    end

Fixes #19090.
Fixes #21765.
Fixes #21819.
Fixes #24359.

Signed-off-by: Jeremy Daer <jeremydaer@gmail.com>

1 files changed, 16 insertions, 0 deletions

diff --git a/activerecord/test/cases/adapters/postgresql/postgresql_adapter_test.rb b/activerecord/test/cases/adapters/postgresql/postgresql_adapter_test.rb
index 8b08ebc3c4..9832df7839 100644
--- a/activerecord/test/cases/adapters/postgresql/postgresql_adapter_test.rb
+++ b/activerecord/test/cases/adapters/postgresql/postgresql_adapter_test.rb
@@ -259,6 +259,22 @@ module ActiveRecord
         end
       end
 
+      def test_expression_index
+        with_example_table do
+          @connection.add_index 'ex', 'mod(id, 10), abs(number)', name: 'expression'
+          index = @connection.indexes('ex').find { |idx| idx.name == 'expression' }
+          assert_equal 'mod(id, 10), abs(number)', index.columns
+        end
+      end
+
+      def test_index_with_opclass
+        with_example_table do
+          @connection.add_index 'ex', 'data varchar_pattern_ops', name: 'with_opclass'
+          index = @connection.indexes('ex').find { |idx| idx.name == 'with_opclass' }
+          assert_equal 'data varchar_pattern_ops', index.columns
+        end
+      end
+
       def test_columns_for_distinct_zero_orders
         assert_equal "posts.id",
           @connection.columns_for_distinct("posts.id", [])