Added field on view

app/models/formula.rb

@@ -24,9 +24,14 @@
 class Formula < ApplicationRecord
   belongs_to :calculator
 
+  PRIORITY_RANGE = 0..10
+
   validates_with FormulaValidator
 
   validates :uk_label, :en_label, :uk_unit, :en_unit, :expression, presence: true
   validates :uk_label, :en_label, length: { minimum: 3, maximum: 50 }
   validates :en_unit, :uk_unit, length: { minimum: 1, maximum: 30 }
+  validates :priority, numericality: { greater_than_or_equal_to: 0 }
+
+  scope :ordered_by_priority, -> { order(:priority) }
 end

app/views/account/calculators/partials/_formula_fields.html.erb

@@ -1,6 +1,7 @@
 <div class="nested-fields">
   <%= f.input :en_label, label: "Formula Label:" %>
   <%= f.input :uk_label, label: "Uk Formula Label:" %>
+  <%= f.input :priority, collection: Formula::PRIORITY_RANGE, wrapper: :custom_vertical_select %>
   <%= f.input :expression, label: "Formula Expression:" %>
 
   <%= f.input :uk_unit, label: "Uk Unit Label:" %>

spec/models/formula_spec.rb

@@ -27,7 +27,8 @@
   let(:local_prefix_formula) { "activerecord.errors.models.formula.attributes" }
   let(:calculator) { create(:calculator) }
   let!(:formula) { build(:formula, expression: "a + b", calculator: calculator) }
-  let!(:formula_with_priority) { build(:formula, expression: "a + b", calculator: calculator, priority: 2) }
+  let!(:formula_with_priority_2) { build(:formula, expression: "a + b", calculator: calculator, priority: 2) }
+
 
   describe "validations" do
     it { is_expected.to validate_presence_of(:uk_label) }
@@ -39,6 +40,7 @@
     it { is_expected.to validate_presence_of(:en_unit) }
     it { is_expected.to validate_length_of(:en_unit).is_at_least(1).is_at_most(30) }
     it { is_expected.to validate_presence_of(:expression) }
+    it { is_expected.to validate_numericality_of(:priority).is_greater_than_or_equal_to(0) }
 
     context "formula has all fields initialized" do
       before do
@@ -70,7 +72,7 @@
     end
 
     it "allows setting a specific priority value" do
-      expect(formula_with_priority.priority).to eq(2)
+      expect(formula_with_priority_2.priority).to eq(2)
     end
   end