Add dataset filter methods

README.md

@@ -106,6 +106,34 @@ item.created? # => true
 item.selected? # => false
 ```
 
+### Filter methods
+
+Plugin can define dataset methods for all enum values:
+
+```ruby
+Item.plugin :enum_values, filter_methods: true # default is `false`
+
+Item.dataset.one # => #<Sequel::Dataset: "SELECT * FROM \"items\" WHERE (\"type\" = 'one')">
+Item.dataset.another # => #<Sequel::Dataset: "SELECT * FROM \"items\" WHERE (\"type\" = 'another')">
+
+Item.dataset.created # => #<Sequel::Dataset: "SELECT * FROM \"items\" WHERE (\"status\" = 'created')">
+Item.dataset.selected # => #<Sequel::Dataset: "SELECT * FROM \"items\" WHERE (\"status\" = 'selected')">
+```
+
+Or just for specific fields:
+
+```ruby
+Item.plugin :enum_values, filter_methods: %i[status]
+# or just `:status` for single value
+
+item = Item.new(type: 'one', status: 'created')
+
+Item.dataset.one # => NoMethodError
+
+Item.dataset.created # => #<Sequel::Dataset: "SELECT * FROM \"items\" WHERE (\"status\" = 'created')">
+Item.dataset.selected # => #<Sequel::Dataset: "SELECT * FROM \"items\" WHERE (\"status\" = 'selected')">
+```
+
 ## Development
 
 After checking out the repo, run `bundle install` to install dependencies.

lib/sequel/plugins/enum_values.rb

@@ -23,6 +23,9 @@ def self.apply(model, _options = {})
 			## @option options [Boolean, Symbol, Array<Symbol>]
 			##   predicate_methods (false)
 			##   enum fields for which predicate methods will be defined
+			## @option options [Boolean, Symbol, Array<Symbol>]
+			##   filter_methods (false)
+			##   enum fields for which dataset filter methods will be defined
 			## @example Disable caching
 			##   Item.plugin :enum_values, caching: false
 			## @example Define predicate methods for all enum fields
@@ -31,18 +34,17 @@ def self.apply(model, _options = {})
 			##   Item.plugin :enum_values, predicate_methods: %[status type]
 			## @example Define predicate methods for specific enum field
 			##   Item.plugin :enum_values, predicate_methods: :status
+			## @example Define filter methods for all enum fields
+			##   Item.plugin :enum_values, filter_methods: true
+			## @example Define filter methods for specific enum field
+			##   Item.plugin :enum_values, filter_methods: :status
+			## @example Define filter methods for specific enum fields
+			##   Item.plugin :enum_values, filter_methods: %[status type]
 			def self.configure(model, options = {})
 				model.instance_exec do
-					@enum_values_caching = options.fetch(:caching, @enum_values_caching)
-
-					predicate_methods = options.fetch(:predicate_methods, false)
+					@enum_values_options = options
 
-					transform_predicate_methods_to_enum_fields(predicate_methods)
-						.each do |field|
-							all_enum_fields[field][:enum_values].each do |enum_value|
-								define_predicate_method field, enum_value
-							end
-						end
+					process_enum_values_options
 				end
 			end
 
@@ -68,20 +70,30 @@ def enum_values(field)
 
 				private
 
-				def transform_predicate_methods_to_enum_fields(predicate_methods)
-					case predicate_methods
-					when TrueClass
-						all_enum_fields.keys
-					when FalseClass
-						[]
-					else
-						Array(predicate_methods)
+				def process_enum_values_options
+					@enum_values_caching =
+						@enum_values_options.fetch(:caching, @enum_values_caching)
+
+					process_enum_values_option(:filter_methods) do |field, value|
+						dataset.methods.include?(value.to_sym) &&
+							warn("WARNING: Redefining method #{value}")
+
+						dataset_module { where value, field => value }
+					end
+
+					process_enum_values_option(:predicate_methods) do |field, value|
+						define_method("#{value}?", -> { public_send(field) == value })
 					end
 				end
 
-				def define_predicate_method(field, enum_value)
-					define_method "#{enum_value}?" do
-						public_send(field) == enum_value
+				def process_enum_values_option(key)
+					return unless (option = @enum_values_options[key])
+
+					enum_fields = all_enum_fields
+					enum_fields = enum_fields.slice(*option) unless option == true
+
+					enum_fields.each do |field, field_schema|
+						field_schema[:enum_values].each { |value| yield field, value }
 					end
 				end
 

spec/sequel/plugins/enum_values_spec.rb

@@ -1,7 +1,7 @@
 # frozen_string_literal:true
 
 describe Sequel::Plugins::EnumValues do
-	type_enum_values = %w[first second third]
+	type_enum_values = %w[one another yet_another]
 	status_enum_values = %w[created selected canceled]
 	item_enum_values = type_enum_values + status_enum_values
 
@@ -71,6 +71,10 @@
 		end
 
 		describe '.configure' do
+			let(:enum_values_options) { {} }
+
+			before { item_class.plugin :enum_values, **enum_values_options }
+
 			describe 'caching option' do
 				shared_examples 'works correctly' do
 					before do
@@ -107,10 +111,7 @@
 						5.times { item_class.enum_values(:type) }
 					end
 
-					before do
-						item_class.plugin :enum_values, caching: true
-					end
-
+					let(:enum_values_options) { { caching: true } }
 					let(:all_enum_fields_received_times) { 1 }
 					let(:schema_received_times) { 1 }
 
@@ -122,10 +123,7 @@
 						5.times { item_class.enum_values(:type) }
 					end
 
-					before do
-						item_class.plugin :enum_values, caching: false
-					end
-
+					let(:enum_values_options) { { caching: false } }
 					let(:all_enum_fields_received_times) { 5 }
 					let(:schema_received_times) { 5 }
 
@@ -180,29 +178,23 @@
 				end
 
 				context 'with true value' do
-					before do
-						item_class.plugin :enum_values, predicate_methods: true
-					end
+					let(:enum_values_options) { { predicate_methods: true } }
 
 					include_examples 'for all enum predicate methods',
 						item_enum_predicate_methods,
 						-> { expect(subject).to be false }
 				end
 
 				context 'with false value' do
-					before do
-						item_class.plugin :enum_values, predicate_methods: false
-					end
+					let(:enum_values_options) { { predicate_methods: false } }
 
 					include_examples 'for all enum predicate methods',
 						item_enum_predicate_methods,
 						-> { expect { subject }.to raise_error(NoMethodError) }
 				end
 
 				context 'with Array value' do
-					before do
-						item_class.plugin :enum_values, predicate_methods: %i[status]
-					end
+					let(:enum_values_options) { { predicate_methods: %i[status] } }
 
 					include_examples 'for all enum predicate methods',
 						status_enum_predicate_methods,
@@ -214,9 +206,7 @@
 				end
 
 				context 'with Symbol value' do
-					before do
-						item_class.plugin :enum_values, predicate_methods: :status
-					end
+					let(:enum_values_options) { { predicate_methods: :status } }
 
 					include_examples 'for all enum predicate methods',
 						status_enum_predicate_methods,
@@ -227,6 +217,93 @@
 						-> { expect { subject }.to raise_error(NoMethodError) }
 				end
 			end
+
+			shared_context('with filter_methods environment') do
+				subject(:enum_filter) { item_class.dataset.public_send(enum_value) }
+
+				let(:filter_sql) do
+					"SELECT * FROM \"items\" WHERE (\"#{field}\" = '#{enum_value}')"
+				end
+			end
+
+			shared_examples('returns correct sql') do |field, field_value|
+				subject { enum_filter.sql }
+
+				describe field_value do
+					let(:field) { field }
+					let(:enum_value) { field_value }
+
+					it { is_expected.to eq filter_sql }
+				end
+			end
+
+			shared_examples('raises NoMethodError') do |field_value|
+				describe field_value do
+					let(:enum_value) { field_value }
+
+					it { expect { enum_filter }.to raise_error(NoMethodError) }
+				end
+			end
+
+			describe 'filter_methods default option' do
+				include_context('with filter_methods environment')
+
+				item_enum_values.each do |filter_method_name|
+					include_examples('raises NoMethodError', filter_method_name)
+				end
+			end
+
+			describe 'filter_methods true option' do
+				let(:enum_values_options) { { filter_methods: true } }
+
+				include_context('with filter_methods environment')
+
+				type_enum_values.each do |filter_method_name|
+					include_examples('returns correct sql', :type, filter_method_name)
+				end
+
+				status_enum_values.each do |filter_method_name|
+					include_examples('returns correct sql', :status, filter_method_name)
+				end
+			end
+
+			describe 'filter_methods false option' do
+				let(:enum_values_options) { { filter_methods: false } }
+
+				include_context('with filter_methods environment')
+
+				item_enum_values.each do |filter_method_name|
+					include_examples('raises NoMethodError', filter_method_name)
+				end
+			end
+
+			describe 'filter_methods Array option' do
+				let(:enum_values_options) { { filter_methods: %i[status] } }
+
+				include_context('with filter_methods environment')
+
+				status_enum_values.each do |filter_method_name|
+					include_examples('returns correct sql', :status, filter_method_name)
+				end
+
+				type_enum_values.each do |filter_method_name|
+					include_examples('raises NoMethodError', filter_method_name)
+				end
+			end
+
+			describe 'filter_methods Symbol option' do
+				let(:enum_values_options) { { filter_methods: :status } }
+
+				include_context('with filter_methods environment')
+
+				status_enum_values.each do |filter_method_name|
+					include_examples('returns correct sql', :status, filter_method_name)
+				end
+
+				type_enum_values.each do |filter_method_name|
+					include_examples('raises NoMethodError', filter_method_name)
+				end
+			end
 		end
 	end
 end