Add store promotion rule

backend/app/views/spree/admin/promotions/rules/_store.html.erb

@@ -0,0 +1,6 @@
+<div class="field">
+  <label><%= t("spree.store_rule.choose_stores" ) %></label>
+  <%= select_tag "#{param_prefix}[store_ids][]",
+    options_from_collection_for_select(Spree::Store.all, :id, :name, promotion_rule.store_ids),
+    multiple: true, class: "select2 fullwidth" %>
+</div>

core/app/models/spree/promotion/rules/store.rb

@@ -0,0 +1,20 @@
+module Spree
+  class Promotion
+    module Rules
+      class Store < PromotionRule
+        has_many :promotion_rule_stores, class_name: "Spree::PromotionRuleStore",
+                                         foreign_key: :promotion_rule_id,
+                                         dependent: :destroy
+        has_many :stores, through: :promotion_rule_stores, class_name: "Spree::Store"
+
+        def applicable?(promotable)
+          promotable.is_a?(Spree::Order)
+        end
+
+        def eligible?(order, _options = {})
+          stores.none? || stores.include?(order.store)
+        end
+      end
+    end
+  end
+end

core/app/models/spree/promotion_rule_store.rb

@@ -0,0 +1,8 @@
+module Spree
+  class PromotionRuleStore < Spree::Base
+    self.table_name = "spree_promotion_rules_stores"
+
+    belongs_to :promotion_rule, class_name: "Spree::PromotionRule"
+    belongs_to :store, class_name: "Spree::Store"
+  end
+end

core/config/locales/en.yml

@@ -224,6 +224,8 @@ en:
         form_text: "Apply this promotion to users whose last order was more than X days ago: "
       spree/promotion/rules/user_role:
         description: Order includes User with specified Role(s)
+      spree/promotion/rules/store:
+        description: Available only to the specified stores
       spree/promotion_category:
         name: Name
       spree/property:
@@ -1966,6 +1968,8 @@ en:
       user_has_no_store_credits: "User does not have any available store credit"
     store_credit_category:
       default: Default
+    store_rule:
+      choose_stores: Choose Stores
     street_address: Street Address
     street_address_2: Street Address (cont'd)
     subtotal: Subtotal

core/db/migrate/20180202190713_create_promotion_rule_stores.rb

@@ -0,0 +1,10 @@
+class CreatePromotionRuleStores < ActiveRecord::Migration[5.1]
+  def change
+    create_table :spree_promotion_rules_stores do |t|
+      t.references :store, foreign_key: { to_table: "spree_stores" }
+      t.references :promotion_rule, foreign_key: { to_table: "spree_promotion_rules" }
+
+      t.timestamps
+    end
+  end
+end

core/lib/spree/app_configuration.rb

@@ -444,6 +444,7 @@ def environment
             Spree::Promotion::Rules::OptionValue
             Spree::Promotion::Rules::FirstRepeatPurchaseSince
             Spree::Promotion::Rules::UserRole
+            Spree::Promotion::Rules::Store
           ]
 
           promos.actions = %w[

core/spec/models/spree/promotion/rules/store_spec.rb

@@ -0,0 +1,33 @@
+require "rails_helper"
+
+RSpec.describe Spree::Promotion::Rules::Store, type: :model do
+  let(:rule) { described_class.new }
+
+  context "#eligible?(order)" do
+    let(:order) { Spree::Order.new }
+
+    it "is eligible if no stores are provided" do
+      expect(rule).to be_eligible(order)
+    end
+
+    it "is eligible if stores include the order's store" do
+      default_store = Spree::Store.new(name: "Default")
+      other_store = Spree::Store.new(name: "Other")
+
+      rule.stores = [default_store, other_store]
+      order.store = default_store
+
+      expect(rule).to be_eligible(order)
+    end
+
+    it "is not eligible if order is placed in a different store" do
+      default_store = Spree::Store.new(name: "Default")
+      other_store = Spree::Store.new(name: "Other")
+
+      rule.stores = [other_store]
+      order.store = default_store
+
+      expect(rule).not_to be_eligible(order)
+    end
+  end
+end