Add support for json column to Sequel container backend

lib/mobility/backends/sequel/container.rb

@@ -8,7 +8,8 @@ module Backends
     class Sequel::Container
       include Sequel
 
-      require 'mobility/backends/sequel/container/query_methods'
+      require 'mobility/backends/sequel/container/json_query_methods'
+      require 'mobility/backends/sequel/container/jsonb_query_methods'
 
       # @return [Symbol] name of container column
       attr_reader :column_name
@@ -47,6 +48,12 @@ def write(locale, value, _ = nil)
       # @option options [Symbol] column_name (:translations) Name of column on which to store translations
       def self.configure(options)
         options[:column_name] ||= :translations
+        options[:column_name] = options[:column_name].to_sym
+        column_name, db_schema = options[:column_name], options[:model_class].db_schema
+        options[:column_type] = db_schema[column_name] && (db_schema[column_name][:db_type]).to_sym
+        unless %i[json jsonb].include?(options[:column_type])
+          raise InvalidColumnType, "#{options[:column_name]} must be a column of type json or jsonb"
+        end
       end
       # @!endgroup
       #
@@ -57,6 +64,8 @@ def each_locale
         end
       end
 
+      backend_class = self
+
       setup do |attributes, options|
         column_name = options[:column_name]
         before_validation = Module.new do
@@ -73,9 +82,14 @@ def each_locale
 
         plugin :defaults_setter
         attributes.each { |attribute| default_values[attribute.to_sym] = {} }
-      end
 
-      setup_query_methods(QueryMethods)
+        query_methods = backend_class.const_get("#{options[:column_type].capitalize}QueryMethods")
+        extend(Module.new do
+          define_method ::Mobility.query_method do
+            super().with_extend(query_methods.new(attributes, options))
+          end
+        end)
+      end
 
       private
 
@@ -94,6 +108,8 @@ def set_attribute_translation(locale, value)
         end
         translations[locale.to_s][attribute] = value
       end
+
+      class InvalidColumnType < StandardError; end
     end
   end
 end

lib/mobility/backends/sequel/container/json_query_methods.rb

@@ -0,0 +1,34 @@
+# frozen_string_literal: true
+require "mobility/backends/sequel/pg_query_methods"
+require "mobility/backends/sequel/query_methods"
+
+Sequel.extension :pg_json, :pg_json_ops
+
+module Mobility
+  module Backends
+    class Sequel::Container::JsonQueryMethods < Sequel::QueryMethods
+      include Sequel::PgQueryMethods
+      attr_reader :column_name
+
+      def initialize(attributes, options)
+        super
+        @column_name = options[:column_name]
+        define_query_methods
+      end
+
+      private
+
+      def matches(key, value, locale)
+        build_op(column_name)[locale].get_text(key.to_s) =~ value.to_s
+      end
+
+      def has_locale(key, locale)
+        build_op(column_name)[locale].get_text(key.to_s) !~ nil
+      end
+
+      def build_op(key)
+        ::Sequel.pg_json_op(key)
+      end
+    end
+  end
+end

lib/mobility/backends/sequel/container/query_methods.rb → lib/mobility/backends/sequel/container/jsonb_query_methods.rb

@@ -6,7 +6,7 @@
 
 module Mobility
   module Backends
-    class Sequel::Container::QueryMethods < Sequel::QueryMethods
+    class Sequel::Container::JsonbQueryMethods < Sequel::QueryMethods
       include Sequel::PgQueryMethods
       attr_reader :column_name
 

spec/mobility/backends/active_record/container_spec.rb

@@ -108,7 +108,8 @@
       StringColumnPost.extend Mobility
       expect {
         StringColumnPost.translates :title, backend: :container, column_name: :foo
-      }.to raise_error(Mobility::Backends::ActiveRecord::Container::InvalidColumnType)
+      }.to raise_error(Mobility::Backends::ActiveRecord::Container::InvalidColumnType,
+                       "foo must be a column of type json or jsonb")
     end
   end
 end if Mobility::Loaded::ActiveRecord

spec/mobility/backends/sequel/container_spec.rb

@@ -61,19 +61,35 @@
     end
   end
 
-  context "with a different column_name" do
+  context "with a json column_name" do
     before(:all) do
-      DB.create_table!(:foo_posts) { primary_key :id; jsonb :foo, default: '""'; TrueClass :published }
+      DB.create_table!(:json_container_posts) { primary_key :id; json :json_translations, default: '{}'; TrueClass :published }
     end
     before(:each) do
-      stub_const 'FooPost', Class.new(Sequel::Model)
-      FooPost.dataset = DB[:foo_posts]
-      FooPost.extend Mobility
-      FooPost.translates :title, :content, backend: :container, presence: false, cache: false, column_name: :foo
+      stub_const 'JsonContainerPost', Class.new(Sequel::Model)
+      JsonContainerPost.dataset = DB[:json_container_posts]
+      JsonContainerPost.extend Mobility
+      JsonContainerPost.translates :title, :content, backend: :container, presence: false, cache: false, column_name: :json_translations
     end
-    after(:all) { DB.drop_table?(:foo_posts) }
+    after(:all) { DB.drop_table?(:json_container_posts) }
 
-    include_accessor_examples 'FooPost'
-    include_querying_examples 'FooPost'
+    include_accessor_examples 'JsonContainerPost'
+    include_querying_examples 'JsonContainerPost'
+  end
+
+  context "with a non-json/jsonb column" do
+    before(:all) do
+      DB.create_table!(:string_column_posts) { primary_key :id; String :foo, default: ''; TrueClass :published }
+    end
+    after(:all) { DB.drop_table?(:string_column_posts) }
+
+    it "raises InvalidColumnType exception" do
+      stub_const 'StringColumnPost', Class.new(Sequel::Model)
+      StringColumnPost.dataset = DB[:string_column_posts]
+      StringColumnPost.extend Mobility
+      expect { StringColumnPost.translates :title, backend: :container, column_name: :foo
+      }.to raise_error(Mobility::Backends::Sequel::Container::InvalidColumnType,
+                       "foo must be a column of type json or jsonb")
+    end
   end
 end if Mobility::Loaded::Sequel && ENV['DB'] == 'postgres'