feat: #10 validate tiem is between 0 and 23 hours

backend/app/models/availability.rb

@@ -1,3 +1,5 @@
 class Availability < ApplicationRecord
   belongs_to :engineer
+
+  validates :time, inclusion: { in: 0..23, message: "must be between 0 and 23" }
 end

backend/spec/models/availability_spec.rb

@@ -0,0 +1,22 @@
+require 'rails_helper'
+
+RSpec.describe Availability, type: :model do
+  let(:engineer) { create(:engineer) }
+
+  it "is valid with a time between 0 and 23" do
+    availability = Availability.new(engineer: engineer, week: "2024-01", day: "Monday", time: 10)
+    expect(availability).to be_valid
+  end
+
+  it "is invalid with a time less than 0" do
+    availability = Availability.new(engineer: engineer, week: "2024-01", day: "Monday", time: -1)
+    expect(availability).to_not be_valid
+    expect(availability.errors[:time]).to include("must be between 0 and 23")
+  end
+
+  it "is invalid with a time greater than 23" do
+    availability = Availability.new(engineer: engineer, week: "2024-01", day: "Monday", time: 24)
+    expect(availability).to_not be_valid
+    expect(availability.errors[:time]).to include("must be between 0 and 23")
+  end
+end