Merge measured-rails into this gem

.github/workflows/ci.yml

@@ -15,9 +15,14 @@ jobs:
           - '3.2'
         gemfile:
           - Gemfile
-          - gemfiles/activesupport-6.0.gemfile
-          - gemfiles/activesupport-6.1.gemfile
-          - gemfiles/activesupport-7.0.gemfile
+          - gemfiles/rails-6.0.gemfile
+          - gemfiles/rails-6.1.gemfile
+          - gemfiles/rails-7.0.gemfile
+          - gemfiles/rails-edge.gemfile
+        exclude:
+          # Rails Edge only supports Ruby >= 3.1
+          - ruby: '3.0'
+            gemfile: gemfiles/rails-edge.gemfile
 
     name: Ruby ${{ matrix.ruby }} ${{ matrix.gemfile }}
     steps:

Gemfile

@@ -1,3 +1,5 @@
 source 'https://rubygems.org'
 
 gemspec
+
+gem "activerecord"

gemfiles/activesupport-6.0.gemfile → gemfiles/rails-6.0.gemfile

@@ -3,3 +3,4 @@ source 'https://rubygems.org'
 gemspec path: '..'
 
 gem 'activesupport', '~> 6.0'
+gem "activerecord", '~> 6.0'

gemfiles/activesupport-6.1.gemfile → gemfiles/rails-6.1.gemfile

@@ -3,3 +3,4 @@ source 'https://rubygems.org'
 gemspec path: '..'
 
 gem 'activesupport', '~> 6.1'
+gem "activerecord", '~> 6.1'

gemfiles/activesupport-7.0.gemfile → gemfiles/rails-7.0.gemfile

@@ -3,3 +3,4 @@ source 'https://rubygems.org'
 gemspec path: '..'
 
 gem 'activesupport', '~> 7.0'
+gem 'activerecord', '~> 7.0'

gemfiles/rails-edge.gemfile

@@ -0,0 +1,6 @@
+source 'https://rubygems.org'
+
+gemspec path: '..'
+
+gem 'activesupport', github: 'rails/rails', branch: 'main'
+gem 'activerecord', github: 'rails/rails', branch: 'main'

lib/measured.rb

@@ -4,3 +4,5 @@
 require "measured/units/length"
 require "measured/units/weight"
 require "measured/units/volume"
+
+require "measured/railtie" if defined?(Rails::Railtie)

lib/measured/rails/active_record.rb

@@ -0,0 +1,130 @@
+# frozen_string_literal: true
+
+module Measured::Rails::ActiveRecord
+  extend ActiveSupport::Concern
+
+  module ClassMethods
+    def measured(measured_class, *fields)
+      options = fields.extract_options!
+      options = {}.merge(options)
+
+      measured_class = measured_class.constantize if measured_class.is_a?(String)
+      unless measured_class.is_a?(Class) && measured_class.ancestors.include?(Measured::Measurable)
+        raise Measured::Rails::Error, "Expecting #{ measured_class } to be a subclass of Measured::Measurable"
+      end
+
+      options[:class] = measured_class
+
+      fields.map(&:to_sym).each do |field|
+        raise Measured::Rails::Error, "The field #{ field } has already been measured" if measured_fields.key?(field)
+
+        measured_fields[field] = options
+
+        unit_field_name = if options[:unit_field_name]
+          measured_fields[field][:unit_field_name] = options[:unit_field_name].to_s
+        else
+          "#{ field }_unit"
+        end
+
+        value_field_name = if options[:value_field_name]
+          measured_fields[field][:value_field_name] = options[:value_field_name].to_s
+        else
+          "#{ field }_value"
+        end
+
+        # Reader to retrieve measured object
+        define_method(field) do
+          value = public_send(value_field_name)
+          unit = public_send(unit_field_name)
+
+          return nil unless value && unit
+
+          instance = instance_variable_get("@measured_#{ field }") if instance_variable_defined?("@measured_#{ field }")
+          new_instance = begin
+            measured_class.new(value, unit)
+          rescue Measured::UnitError
+            nil
+          end
+
+          if instance == new_instance
+            instance
+          else
+            instance_variable_set("@measured_#{ field }", new_instance)
+          end
+        end
+
+        # Writer to assign measured object
+        define_method("#{ field }=") do |incoming|
+          if incoming.is_a?(measured_class)
+            instance_variable_set("@measured_#{ field }", incoming)
+            precision = self.column_for_attribute(value_field_name).precision
+            scale = self.column_for_attribute(value_field_name).scale
+            rounded_to_scale_value = incoming.value.round(scale)
+
+            max = self.class.measured_fields[field][:max_on_assignment]
+            if max && rounded_to_scale_value > max
+              rounded_to_scale_value = max
+            elsif rounded_to_scale_value.to_i.to_s.length > (precision - scale)
+              raise Measured::Rails::Error, "The value #{rounded_to_scale_value} being set for column '#{value_field_name}' has too many significant digits. Please ensure it has no more than #{precision - scale} significant digits."
+            end
+
+            public_send("#{ value_field_name }=", rounded_to_scale_value)
+            public_send("#{ unit_field_name }=", incoming.unit.name)
+          else
+            instance_variable_set("@measured_#{ field }", nil)
+            public_send("#{ value_field_name}=", nil)
+            public_send("#{ unit_field_name }=", nil)
+          end
+        end
+
+        # Writer to override unit assignment
+        redefine_method("#{ unit_field_name }=") do |incoming|
+          unit_name = measured_class.unit_system.unit_for(incoming).try!(:name)
+          write_attribute(unit_field_name, unit_name || incoming)
+        end
+      end
+    end
+
+    def measured_fields
+      @measured_fields ||= {}
+    end
+
+  end
+
+  module Length
+    extend ActiveSupport::Concern
+
+    module ClassMethods
+      def measured_length(*fields)
+        measured(Measured::Length, *fields)
+      end
+    end
+  end
+
+  module Volume
+    extend ActiveSupport::Concern
+
+    module ClassMethods
+      def measured_volume(*fields)
+        measured(Measured::Volume, *fields)
+      end
+    end
+  end
+
+  module Weight
+    extend ActiveSupport::Concern
+
+    module ClassMethods
+      def measured_weight(*fields)
+        measured(Measured::Weight, *fields)
+      end
+    end
+  end
+end
+
+::ActiveRecord::Base.include(
+  Measured::Rails::ActiveRecord,
+  Measured::Rails::ActiveRecord::Length,
+  Measured::Rails::ActiveRecord::Volume,
+  Measured::Rails::ActiveRecord::Weight,
+)

lib/measured/rails/validations.rb

@@ -0,0 +1,68 @@
+# frozen_string_literal: true
+
+require "active_model/validations"
+
+class MeasuredValidator < ActiveModel::EachValidator
+  CHECKS = {
+    greater_than: :>,
+    greater_than_or_equal_to: :>=,
+    equal_to: :==,
+    less_than: :<,
+    less_than_or_equal_to: :<=,
+  }.freeze
+
+  def validate_each(record, attribute, measurable)
+    measured_config = record.class.measured_fields[attribute]
+    unit_field_name = measured_config[:unit_field_name] || "#{ attribute }_unit"
+    value_field_name = measured_config[:value_field_name] || "#{ attribute }_value"
+
+    measured_class = measured_config[:class]
+
+    measurable_unit_name = record.public_send(unit_field_name)
+    measurable_value = record.public_send(value_field_name)
+
+    return unless measurable_unit_name.present? || measurable_value.present?
+
+    measurable_unit = measured_class.unit_system.unit_for(measurable_unit_name)
+    record.errors.add(attribute, message(record, "is not a valid unit")) unless measurable_unit
+
+    if options[:units] && measurable_unit.present?
+      valid_units = Array(options[:units]).map { |unit| measured_class.unit_system.unit_for(unit) }
+      record.errors.add(attribute, message(record, "is not a valid unit")) unless valid_units.include?(measurable_unit)
+    end
+
+    if measurable_unit && measurable_value.present?
+      options.slice(*CHECKS.keys).each do |option, value|
+        comparable_value = value_for(value, record)
+        comparable_value = measured_class.new(comparable_value, measurable_unit) unless comparable_value.is_a?(Measured::Measurable)
+        unless measurable.public_send(CHECKS[option], comparable_value)
+          record.errors.add(attribute, message(record, "#{measurable.to_s} must be #{CHECKS[option]} #{comparable_value}"))
+        end
+      end
+    end
+  end
+
+  private
+
+  def message(record, default_message)
+    if options[:message].respond_to?(:call)
+      options[:message].call(record)
+    else
+      options[:message] || default_message
+    end
+  end
+
+  def value_for(key, record)
+    value = case key
+    when Proc
+      key.call(record)
+    when Symbol
+      record.send(key)
+    else
+      key
+    end
+
+    raise ArgumentError, ":#{ value } must be a number or a Measurable object" unless (value.is_a?(Numeric) || value.is_a?(Measured::Measurable))
+    value
+  end
+end

lib/measured/railtie.rb

@@ -0,0 +1,12 @@
+# frozen_string_literal: true
+
+module Measured
+  class Rails < ::Rails::Railtie
+    class Error < StandardError ; end
+
+    ActiveSupport.on_load(:active_record) do
+      require "measured/rails/active_record"
+      require "measured/rails/validations"
+    end
+  end
+end

lib/tapioca/dsl/compilers/measured_rails.rb

@@ -0,0 +1,108 @@
+# typed: strict
+# frozen_string_literal: true
+
+return unless defined?(::Measured::Rails::ActiveRecord)
+
+module Tapioca
+  module Dsl
+    module Compilers
+      # `Tapioca::Dsl::Compilers::MeasuredRails` refines RBI files for subclasses of
+      # [`ActiveRecord::Base`](https://api.rubyonrails.org/classes/ActiveRecord/Base.html)
+      # that utilize the [`measured-rails`](https://github.com/shopify/measured-rails) DSL.
+      # This compiler is only responsible for defining the methods that would be created
+      # for measured fields that are defined in the Active Record model.
+      #
+      # For example, with the following model class:
+      #
+      # ~~~rb
+      # class Package < ActiveRecord::Base
+      #   measured Measured::Weight, :minimum_weight
+      #   measured Measured::Length, :total_length
+      #   measured Measured::Volume, :total_volume
+      # end
+      # ~~~
+      #
+      # this compiler will produce the following methods in the RBI file
+      # `package.rbi`:
+      #
+      # ~~~rbi
+      # # package.rbi
+      # # typed: true
+      #
+      # class Package
+      #   include GeneratedMeasuredRailsMethods
+      #
+      #   module GeneratedMeasuredRailsMethods
+      #     sig { returns(T.nilable(Measured::Weight)) }
+      #     def minimum_weight; end
+      #
+      #     sig { params(value: T.nilable(Measured::Weight)).void }
+      #     def minimum_weight=(value); end
+      #
+      #     sig { returns(T.nilable(Measured::Length)) }
+      #     def total_length; end
+      #
+      #     sig { params(value: T.nilable(Measured::Length)).void }
+      #     def total_length=(value); end
+      #
+      #     sig { returns(T.nilable(Measured::Volume)) }
+      #     def total_volume; end
+      #
+      #     sig { params(value: T.nilable(Measured::Volume)).void }
+      #     def total_volume=(value); end
+      #   end
+      # end
+      # ~~~
+      class MeasuredRails < ::Tapioca::Dsl::Compiler
+        extend T::Sig
+
+        ConstantType = type_member { {
+          fixed: T.all(
+            T.class_of(::ActiveRecord::Base),
+            ::Measured::Rails::ActiveRecord::ClassMethods
+          )
+        } }
+
+        MeasuredMethodsModuleName = T.let("GeneratedMeasuredRailsMethods", String)
+
+        sig { override.void }
+        def decorate
+          return if constant.measured_fields.empty?
+
+          root.create_path(constant) do |model|
+            model.create_module(MeasuredMethodsModuleName) do |mod|
+              populate_measured_methods(mod)
+            end
+
+            model.create_include(MeasuredMethodsModuleName)
+          end
+        end
+
+        sig { override.returns(T::Enumerable[Module]) }
+        def self.gather_constants
+          descendants_of(::ActiveRecord::Base)
+        end
+
+        private
+
+        sig { params(model: RBI::Scope).void }
+        def populate_measured_methods(model)
+          constant.measured_fields.each do |field, attrs|
+            klass = attrs[:class].to_s
+
+            model.create_method(
+              field.to_s,
+              return_type: as_nilable_type(klass)
+            )
+
+            model.create_method(
+              "#{field}=",
+              parameters: [create_param("value", type: as_nilable_type(klass))],
+              return_type: "void"
+            )
+          end
+        end
+      end
+    end
+  end
+end

measured.gemspec

@@ -33,4 +33,7 @@ Gem::Specification.new do |spec|
   spec.add_development_dependency "minitest-reporters"
   spec.add_development_dependency "mocha", ">= 1.4.0"
   spec.add_development_dependency "pry"
+  spec.add_development_dependency "combustion"
+  spec.add_development_dependency "sqlite3"
+  spec.add_development_dependency "tapioca"
 end

test/internal/app/models/thing.rb

@@ -0,0 +1,14 @@
+# frozen_string_literal: true
+class Thing < ActiveRecord::Base
+
+  measured_length :length, :width
+
+  measured Measured::Length, :height
+  measured Measured::Volume, :volume
+
+  measured_weight :total_weight
+
+  measured "Measured::Weight", :extra_weight
+
+  measured_length :length_with_max_on_assignment, {max_on_assignment: 500}
+end