Add `with_primary_key` to AssociationMatchers

NEWS.md

@@ -27,11 +27,14 @@
 * Tweak `allow_value` failure message so that it reads a bit nicer when listing
   existing errors.
 
+* Add ability to test `:primary_key` option on associations. ([#597])
+
 [#591]: https://github.com/thoughtbot/shoulda-matchers/pull/591
 [#592]: https://github.com/thoughtbot/shoulda-matchers/pull/592
 [#588]: https://github.com/thoughtbot/shoulda-matchers/pull/588
 [#584]: https://github.com/thoughtbot/shoulda-matchers/pull/584
 [#593]: https://github.com/thoughtbot/shoulda-matchers/pull/593
+[#597]: https://github.com/thoughtbot/shoulda-matchers/pull/597
 
 # 2.7.0
 

lib/shoulda/matchers/active_record/association_matcher.rb

@@ -100,6 +100,28 @@ module Shoulda
       #       should belong_to(:ancient_city).class_name('City')
       #     end
       #
+      # ##### with_primary_key
+      #
+      # Use `with_primary_key` to test usage of the `:primary_key` option.
+      #
+      #     class Person < ActiveRecord::Base
+      #       belongs_to :great_country, primary_key: 'country_id'
+      #     end
+      #
+      #     # RSpec
+      #     describe Person do
+      #       it do
+      #         should belong_to(:great_country).
+      #           with_primary_key('country_id')
+      #       end
+      #     end
+      #
+      #     # Test::Unit
+      #     class PersonTest < ActiveSupport::TestCase
+      #       should belong_to(:great_country).
+      #         with_primary_key('country_id')
+      #     end
+      #
       # ##### with_foreign_key
       #
       # Use `with_foreign_key` to test usage of the `:foreign_key` option.
@@ -295,6 +317,24 @@ module Shoulda
       #       should have_many(:hopes).class_name('Dream')
       #     end
       #
+      # ##### with_primary_key
+      #
+      # Use `with_primary_key` to test usage of the `:primary_key` option.
+      #
+      #     class Person < ActiveRecord::Base
+      #       has_many :worries, primary_key: 'worrier_id'
+      #     end
+      #
+      #     # RSpec
+      #     describe Person do
+      #       it { should have_many(:worries).with_primaryu_key('worrier_id') }
+      #     end
+      #
+      #     # Test::Unit
+      #     class PersonTest < ActiveSupport::TestCase
+      #       should have_many(:worries).with_primary_key('worrier_id')
+      #     end
+      #
       # ##### with_foreign_key
       #
       # Use `with_foreign_key` to test usage of the `:foreign_key` option.
@@ -511,6 +551,24 @@ module Shoulda
       #       should have_one(:contract).dependent(:nullify)
       #     end
       #
+      # ##### with_primary_key
+      #
+      # Use `with_primary_key` to test usage of the `:primary_key` option.
+      #
+      #     class Person < ActiveRecord::Base
+      #       has_one :job, primary_key: 'worker_id'
+      #     end
+      #
+      #     # RSpec
+      #     describe Person do
+      #       it { should have_one(:job).with_primary_key('worker_id') }
+      #     end
+      #
+      #     # Test::Unit
+      #     class PersonTest < ActiveSupport::TestCase
+      #       should have_one(:job).with_primary_key('worker_id')
+      #     end
+      #
       # ##### with_foreign_key
       #
       # Use `with_foreign_key` to test usage of the `:foreign_key` option.
@@ -814,6 +872,11 @@ module Shoulda
           self
         end
 
+        def with_primary_key(primary_key)
+          @options[:primary_key] = primary_key
+          self
+        end
+
         def validate(validate = true)
           @options[:validate] = validate
           self
@@ -846,6 +909,7 @@ module Shoulda
             macro_correct? &&
             (polymorphic? || class_exists?) &&
             foreign_key_exists? &&
+            primary_key_exists? &&
             class_name_correct? &&
             join_table_correct? &&
             autosave_correct? &&
@@ -928,10 +992,19 @@ module Shoulda
           end
         end
 
+        def macro_supports_primary_key?
+          macro == :belongs_to || 
+            ([:has_many, :has_one].include?(macro) && !through?)
+        end
+
         def foreign_key_exists?
           !(belongs_foreign_key_missing? || has_foreign_key_missing?)
         end
 
+        def primary_key_exists?
+          !macro_supports_primary_key? || primary_key_correct?(model_class)
+        end
+
         def belongs_foreign_key_missing?
           macro == :belongs_to && !class_has_foreign_key?(model_class)
         end
@@ -1034,6 +1107,19 @@ module Shoulda
           end
         end
 
+        def primary_key_correct?(klass)
+          if options.key?(:primary_key)
+            if option_verifier.correct_for_string?(:primary_key, options[:primary_key])
+              true
+            else
+              @missing = "#{klass} does not have a #{options[:primary_key]} primary key"
+              false
+            end
+          else
+            true
+          end
+        end
+
         def foreign_key
           if foreign_key_reflection
             if foreign_key_reflection.respond_to?(:foreign_key)

spec/shoulda/matchers/active_record/association_matcher_spec.rb

@@ -29,6 +29,22 @@ describe Shoulda::Matchers::ActiveRecord::AssociationMatcher do
       expect(Child.new).to belong_to(:parent)
     end
 
+    it 'accepts an association using an existing custom primary key' do
+      define_model :parent
+      define_model :child, parent_id: :integer, custom_primary_key: :integer do
+        belongs_to :parent, primary_key: :custom_primary_key
+      end
+      expect(Child.new).to belong_to(:parent).with_primary_key(:custom_primary_key)
+    end
+
+    it 'rejects an association with a bad :primary_key option' do
+      matcher = belong_to(:parent).with_primary_key(:custom_primary_key)
+
+      expect(belonging_to_parent).not_to matcher
+
+      expect(matcher.failure_message).to match(/Child does not have a custom_primary_key primary key/)
+    end
+
     it 'accepts a polymorphic association' do
       define_model :child, parent_type: :string, parent_id: :integer do
         belongs_to :parent, polymorphic: true
@@ -288,6 +304,22 @@ describe Shoulda::Matchers::ActiveRecord::AssociationMatcher do
       expect(Parent.new).not_to have_many(:children)
     end
 
+    it 'accepts an association using an existing custom primary key' do
+      define_model :child, parent_id: :integer
+      define_model :parent, custom_primary_key: :integer do
+        has_many :children, primary_key: :custom_primary_key
+      end
+      expect(Parent.new).to have_many(:children).with_primary_key(:custom_primary_key)
+    end
+
+    it 'rejects an association with a bad :primary_key option' do
+      matcher = have_many(:children).with_primary_key(:custom_primary_key)
+
+      expect(having_many_children).not_to matcher
+
+      expect(matcher.failure_message).to match(/Parent does not have a custom_primary_key primary key/)
+    end
+
     it 'rejects an association with a bad :as option' do
       define_model :child, caretaker_type: :string,
         caretaker_id: :integer
@@ -537,6 +569,22 @@ describe Shoulda::Matchers::ActiveRecord::AssociationMatcher do
       expect(Person.new).to have_one(:detail).with_foreign_key(:detailed_person_id)
     end
 
+    it 'accepts an association using an existing custom primary key' do
+      define_model :detail, person_id: :integer
+      define_model :person, custom_primary_key: :integer do
+        has_one :detail, primary_key: :custom_primary_key
+      end
+      expect(Person.new).to have_one(:detail).with_primary_key(:custom_primary_key)
+    end
+
+    it 'rejects an association with a bad :primary_key option' do
+      matcher = have_one(:detail).with_primary_key(:custom_primary_key)
+
+      expect(having_one_detail).not_to matcher
+
+      expect(matcher.failure_message).to match(/Person does not have a custom_primary_key primary key/)
+    end
+
     it 'rejects an association with a bad :as option' do
       define_model :detail, detailable_id: :integer,
         detailable_type: :string