1 files changed, 65 insertions, 0 deletions
diff --git a/activerecord/test/cases/adapters/mysql2/schema_migrations_test.rb b/activerecord/test/cases/adapters/mysql2/schema_migrations_test.rb
new file mode 100644
index 0000000000..d7d9a2d732
--- /dev/null
+++ b/activerecord/test/cases/adapters/mysql2/schema_migrations_test.rb
@@ -0,0 +1,65 @@
+# frozen_string_literal: true
+
+require "cases/helper"
+
+class SchemaMigrationsTest < ActiveRecord::Mysql2TestCase
+  self.use_transactional_tests = false
+
+  def test_renaming_index_on_foreign_key
+    connection.add_index "engines", "car_id"
+    connection.add_foreign_key :engines, :cars, name: "fk_engines_cars"
+
+    connection.rename_index("engines", "index_engines_on_car_id", "idx_renamed")
+    assert_equal ["idx_renamed"], connection.indexes("engines").map(&:name)
+  ensure
+    connection.remove_foreign_key :engines, name: "fk_engines_cars"
+  end
+
+  def test_initializes_schema_migrations_for_encoding_utf8mb4
+    with_encoding_utf8mb4 do
+      table_name = ActiveRecord::SchemaMigration.table_name
+      connection.drop_table table_name, if_exists: true
+
+      ActiveRecord::SchemaMigration.create_table
+
+      assert connection.column_exists?(table_name, :version, :string)
+    end
+  end
+
+  def test_initializes_internal_metadata_for_encoding_utf8mb4
+    with_encoding_utf8mb4 do
+      table_name = ActiveRecord::InternalMetadata.table_name
+      connection.drop_table table_name, if_exists: true
+
+      ActiveRecord::InternalMetadata.create_table
+
+      assert connection.column_exists?(table_name, :key, :string)
+    end
+  ensure
+    ActiveRecord::InternalMetadata[:environment] = connection.migration_context.current_environment
+  end
+
+  private
+
+    def with_encoding_utf8mb4
+      database_name = connection.current_database
+      database_info = connection.select_one("SELECT * FROM information_schema.schemata WHERE schema_name = '#{database_name}'")
+
+      original_charset = database_info["DEFAULT_CHARACTER_SET_NAME"]
+      original_collation = database_info["DEFAULT_COLLATION_NAME"]
+
+      execute("ALTER DATABASE #{database_name} DEFAULT CHARACTER SET utf8mb4")
+
+      yield
+    ensure
+      execute("ALTER DATABASE #{database_name} DEFAULT CHARACTER SET #{original_charset} COLLATE #{original_collation}")
+    end
+
+    def connection
+      @connection ||= ActiveRecord::Base.connection
+    end
+
+    def execute(sql)
+      connection.execute(sql)
+    end
+end