Association extensions

.yardopts

@@ -0,0 +1,7 @@
+--readme README.md
+--title 'Temporality Documentation'
+--charset utf-8
+--markup markdown
+--private
+'lib/**/*.rb'
+

lib/temporality.rb

@@ -1,7 +1,6 @@
 require 'date'
 
 require 'temporality/version'
-
 require 'temporality/slice_collection'
 require 'temporality/errors'
 require 'temporality/validation'
@@ -14,15 +13,15 @@
 require 'temporality/transaction'
 require 'temporality/association_extensions'
 
-# = Temporality
+# # Temporality
 #
 # Root module for temporal functionality, include it in ActiveRecord classes
 # to benefit from the temporality features.
 #
 # This functionality requires a +starts_on+ and +ends_on+ attribute pair defined
 # on the models in which the module is included.
 #
-# == Example
+# ## Example
 #
 # This will define three classes with temporality constraints. An employment
 # contract will be required to be temporally within the bounds of the legal entity
@@ -66,22 +65,26 @@ module Temporality
   FUTURE_INFINITY = Date.new(5000, 1, 1)
 
   # Prepended modules
-  PREPENDS  = [ AttributeOverrides, Validation ]
+  PREPENDS = [ AttributeOverrides, Validation ]
 
   # Extensions to the included class
-  EXTENDS   = [ Associations, Scopes ]
+  EXTENDS = [ Associations, Scopes ]
 
   # Inclusions for the included class
-  INCLUDES  = [ DefaultBoundaryValues ]
+  INCLUDES = [ DefaultBoundaryValues ]
 
+  #
+  # Sets-up all the required behaviour for temporal functionality on `base`
+  #
+  # @param base [ActiveRecord::Base]
+  #
   def self.included(base)
     PREPENDS.each { |mod| base.prepend(mod) }
     EXTENDS.each  { |mod| base.extend(mod) }
     INCLUDES.each { |mod| base.include(mod) }
-
-    # TODO : On va peut-être pas l'inclure 50 fois ce truc...
-    ActiveRecord::Base.send(:include, DayCount)
   end
 
 end
 
+ActiveRecord::Base.send(:include, Temporality::DayCount)
+

lib/temporality/association_extensions.rb

@@ -1,5 +1,85 @@
 module Temporality
+
+  #
+  # This module provides an override for the `build` method on an association
+  # proxy in order to automatically set the temporal bounds on built children
+  # unless these were explicitly provided.
+  #
   module AssociationExtensions
+
+    #
+    # Override for `ActiveRecord::Relation#build` that provides automatic
+    # values for the temporal bounds.
+    #
+    # @return [ActiveRecord::Base] The built model
+    #
+    def build(**kwargs, &block)
+      with_default_bounds_scope(**kwargs) { super(**kwargs, &block) }
+    end
+
+    #
+    # Override for `ActiveRecord::Relation#create` that provides automatic
+    # values for the temporal bounds.
+    #
+    # @return [ActiveRecord::Base] The built model
+    #
+    def create(**kwargs, &block)
+      with_default_bounds_scope(**kwargs) { super(**kwargs, &block) }
+    end
+
+    #
+    # Override for `ActiveRecord::Relation#create!` that provides automatic
+    # values for the temporal bounds.
+    #
+    # @return [ActiveRecord::Base] The built model
+    #
+    def create!(**kwargs, &block)
+      with_default_bounds_scope(**kwargs) { super(**kwargs, &block) }
+    end
+
+    #
+    # Yields to the given block with a scope defining default values for the
+    # temporal bounds.
+    #
+    def with_default_bounds_scope(**kwargs)
+      return unless block_given?
+
+      owner = proxy_association.owner
+      klass = proxy_association.klass
+
+      starts_on = kwargs[:starts_on]
+      ends_on   = kwargs[:ends_on]
+
+      if temporal_compatible_association?(owner, klass.new)
+        last_child  = scope.order('ends_on ASC').last
+
+        ends_on ||= owner.ends_on
+
+        if scope.count.zero?
+          starts_on ||= owner.starts_on
+        elsif last_child.ends_on < owner.ends_on
+          starts_on ||= last_child.ends_on + 1
+        end
+      end
+
+      starts_on ||= Temporality::PAST_INFINITY
+      ends_on   ||= Temporality::FUTURE_INFINITY
+
+      where(starts_on: starts_on).where(ends_on: ends_on).scoping { yield }
+    end
+
+
+    private
+
+    #
+    # Returns `true` if the association parent and children have temporal bounds
+    #
+    # @return [Boolean]
+    #
+    def temporal_compatible_association?(*models)
+      models.all? { |m| m.respond_to?(:starts_on) && m.respond_to?(:ends_on) }
+    end
+
   end
 end
 

lib/temporality/version.rb

@@ -1,7 +1,7 @@
 module Temporality
 
   # Temporality gem version
-  VERSION = '0.0.5'
+  VERSION = '0.0.6'
 
 end
 

spec/support/models.rb

@@ -6,7 +6,7 @@ class Dummy < ActiveRecord::Base
 
 class Person < ActiveRecord::Base
   include Temporality
-  has_many :dogs
+  has_many :dogs, extend: Temporality::AssociationExtensions
 end
 
 class Dog < ActiveRecord::Base

spec/temporality/association_extensions_spec.rb

@@ -2,33 +2,96 @@
 
 RSpec.describe Temporality::AssociationExtensions do
 
+  # TODO Try with keyword args, when passing a starts_on and ends on it shouldn't override
+
   let(:person)  { Person.create({ starts_on: Date.new(2016, 1, 1), ends_on: Date.new(2016, 12, 31) }) }
 
   describe '#build' do
     let(:dog) { person.dogs.build }
 
-    context 'when creating a child with no sibling records' do
-      it 'should inherit its parents starts_on bound' do
-        expect(dog.starts_on).to eql(person.starts_on)
+    context 'when building a child' do
+      context 'with no siblings' do
+        it 'should inherit its parents starts_on bound' do
+          expect(dog.starts_on).to eql(person.starts_on)
+        end
+
+        it 'should inherit its parents ends_on bound' do
+          expect(dog.ends_on).to eql(person.ends_on)
+        end
       end
 
-      it 'should inherit its parents ends_on bound' do
-        expect(dog.ends_on).to eql(person.ends_on)
+      context 'with existing siblings' do
+        before { person.dogs.create({ starts_on: Date.new(2016, 3, 15), ends_on: Date.new(2016, 6, 30) }) }
+
+        it 'should set starts_on on the child as the date following ends_on on the previous sibling' do
+          expect(dog.starts_on).to eql(Date.new(2016, 7, 1))
+        end
+
+        it 'should inherit its parents ends_on bound' do
+          expect(dog.ends_on).to eql(person.ends_on)
+        end
+      end
+
+      context 'with an incompatible sibling' do
+        before { person.dogs.create({ starts_on: Date.new(2016, 3, 15), ends_on: Date.new(2016, 12, 31) }) }
+
+        it 'should not inherit its parents starts_on bound' do
+          expect(dog.starts_on).to eql(Temporality::PAST_INFINITY)
+        end
+
+        it 'should inherit its parents ends_on bound' do
+          expect(dog.ends_on).to eql(person.ends_on)
+        end
       end
     end
+  end
 
-    context 'when creating a child with existing siblings' do
-      before { person.dogs.create({ starts_on: Date.new(2016, 3, 15), ends_on: Date.new(2016, 6, 30) }) }
+  describe '#create' do
+    context 'when creating a child with defined attributes' do
+      let(:dog) { person.dogs.create(starts_on: Date.new(2016, 12, 13), ends_on: Date.new(2016, 12, 15)) }
 
-      it 'should not inherit its parents starts_on bound' do
-        expect(dog.starts_on).to eql(Temporality::PAST_INFINITY)
+      it 'should not override the start date' do
+        expect(dog.starts_on).to eql(Date.new(2016, 12, 13))
       end
 
-      it 'should not inherit its parents ends_on bound' do
-        expect(dog.ends_on).to eql(Temporality::FUTURE_INFINITY)
+      it 'should not override the end date' do
+        expect(dog.ends_on).to eql(Date.new(2016, 12, 15))
       end
     end
-  end
 
+    context 'when creating a child without defined attributes' do
+      let(:dog) { person.dogs.create }
+
+      context 'with no siblings' do
+        it 'should inherit its parents starts_on bound' do
+          expect(dog.starts_on).to eql(person.starts_on)
+        end
+
+        it 'should inherit its parents ends_on bound' do
+          expect(dog.ends_on).to eql(person.ends_on)
+        end
+      end
+
+      context 'with existing siblings' do
+        before { person.dogs.create({ starts_on: Date.new(2016, 3, 15), ends_on: Date.new(2016, 6, 30) }) }
+
+        it 'should set starts_on on the child as the date following ends_on on the previous sibling' do
+          expect(dog.starts_on).to eql(Date.new(2016, 7, 1))
+        end
+
+        it 'should inherit its parents ends_on bound' do
+          expect(dog.ends_on).to eql(person.ends_on)
+        end
+      end
+
+      context 'with an incompatible sibling' do
+        before { person.dogs.create({ starts_on: Date.new(2016, 3, 15), ends_on: Date.new(2016, 12, 31) }) }
+
+        it 'should fail to create the child' do
+          expect { dog }.to raise_error(Temporality::Violation)
+        end
+      end
+    end
+  end
 end