Don't allow instantiation of DatabaseAdapter directly

Maybe it would make sense, but verification of data type would require a
lot of gymnastics and we see no value in it.

Co-authored-by: Piotr Jurewicz <[email protected]>

Author: fidel

ruby_event_store-active_record/lib/ruby_event_store/active_record/generators/database_adapter.rb

@@ -33,6 +33,8 @@ def initialize(data_type = NOT_SET)
       end
 
       def initialize(adapter_name, data_type)
+        raise UnsupportedAdapter if instance_of?(DatabaseAdapter)
+
         validate_data_type!(data_type)
 
         @adapter_name = adapter_name
@@ -57,6 +59,7 @@ def hash
 
       def self.from_string(adapter_name, data_type = NOT_SET)
         raise NoMethodError unless eql?(DatabaseAdapter)
+
         case adapter_name.to_s.downcase
         when "postgresql", "postgis"
           PostgreSQL.new(data_type)

ruby_event_store-active_record/spec/database_adapter_spec.rb

@@ -50,6 +50,10 @@ module ActiveRecord
         expect { DatabaseAdapter::SQLite.from_string("sqlite") }.to raise_error(NoMethodError)
       end
 
+      specify "don't allow instance of parent class directly" do
+        expect { DatabaseAdapter.new("postgresql", "jsonb") }.to raise_error(UnsupportedAdapter)
+      end
+
       context "data type verification" do
         specify "MySQL supports binary" do
           expect(DatabaseAdapter::MySQL2.new("binary").data_type).to eq("binary")