don't allow transfers of 0 hours and 0 minutes

app/assets/javascripts/give_time.js.coffee

@@ -5,8 +5,13 @@ jQuery.validator.addMethod "either-hours-minutes-informed", ((value, element) ->
 giveTimeReadyFn = () ->
   config =
     submitHandler: (form) ->
-      $(" #transfer_amount ").val($(" #transfer_hours ").val() * 3600 + $(" #transfer_minutes ").val() * 60)
-      form.submit()
+      amount = $("#transfer_hours").val() * 3600 + $("#transfer_minutes").val() * 60
+      $("#transfer_amount").val(amount)
+
+      if amount > 0
+        form.submit()
+      else
+        $(form).find('.form-actions .error').removeClass('invisible').show()
 
   $( "#new_transfer" ).validate(config)
 

app/controllers/transfers_controller.rb

@@ -12,7 +12,7 @@ def create
     if persister.save
       redirect_to redirect_target
     else
-      flash[:error] = transfer.errors.full_messages.to_sentence
+      redirect_to :back, alert: transfer.errors.full_messages.to_sentence
     end
   end
 

app/models/movement.rb

@@ -18,6 +18,8 @@ class Movement < ActiveRecord::Base
           where(created_at: month.beginning_of_month..month.end_of_month)
         }
 
+  validates :amount, numericality: { other_than: 0 }
+
   after_create do
     account.update_balance
   end

app/models/transfer.rb

@@ -17,6 +17,7 @@ class Transfer < ActiveRecord::Base
   has_many :movements, dependent: :destroy
   has_many :events, dependent: :destroy
 
+  validates :amount, numericality: { greater_than: 0 }
   validate :different_source_and_destination
 
   after_create :make_movements
@@ -26,14 +27,6 @@ def make_movements
     movements.create(account: Account.find(destination_id), amount: amount.to_i)
   end
 
-  def movement_from
-    movements.detect {|m| m.amount < 0 }
-  end
-
-  def movement_to
-    movements.detect {|m| m.amount > 0 }
-  end
-
   def source_id
     source.respond_to?(:id) ? source.id : source
   end

app/views/transfers/new.html.erb

@@ -36,7 +36,8 @@
   </div>
 
   <div class="form-actions">
-    <%= f.button :submit, class: "btn btn-default", style: "margin-bottom: 20px;" %>
+    <%= f.button :submit, class: "btn btn-default" %>
+    <label class="error invisible"><%= t ".error_amount" %></label>
   </div>
 <% end %>
 

config/locales/ca.yml

@@ -494,6 +494,8 @@ ca:
       minute:
         one: "%{count} minut"
         other: "%{count} minuts"
+    new:
+      error_amount:
   users:
     edit:
       edit_user: Canviar usuari

config/locales/en.yml

@@ -494,6 +494,8 @@ en:
       minute:
         one: "%{count} minute"
         other: "%{count} minutes"
+    new:
+      error_amount: Time must be greater than 0
   users:
     edit:
       edit_user: Update user

config/locales/es.yml

@@ -494,6 +494,8 @@ es:
       minute:
         one: "%{count} minuto"
         other: "%{count} minutos"
+    new:
+      error_amount:
   users:
     edit:
       edit_user: Cambiar usuario

config/locales/eu.yml

@@ -500,6 +500,8 @@ eu:
       minute:
         one: "%{count}minutu"
         other: "%{count} minutu"
+    new:
+      error_amount:
   users:
     edit:
       edit_user: Erabiltzailea aldatu

config/locales/pt-BR.yml

@@ -494,6 +494,8 @@ pt-BR:
       minute:
         one: "%{count} minuto"
         other: "%{count} minutos"
+    new:
+      error_amount:
   users:
     edit:
       edit_user: Trocar usuário

db/migrate/20181004200104_add_amount_constraint_to_movements.rb

@@ -0,0 +1,10 @@
+class AddAmountConstraintToMovements < ActiveRecord::Migration
+  def change
+    # Destroy movements (and parent transfer) with amount equal to 0
+    Movement.includes(:transfer).where(amount: 0).find_each do |movement|
+      movement.transfer&.destroy
+    end
+
+    execute 'ALTER TABLE movements ADD CONSTRAINT non_zero_amount CHECK(amount != 0)'
+  end
+end

db/schema.rb

@@ -11,7 +11,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 20180924164456) do
+ActiveRecord::Schema.define(version: 20181004200104) do
 
   # These are extensions that must be enabled in order to support this database
   enable_extension "plpgsql"

spec/controllers/transfers_controller_spec.rb

@@ -207,5 +207,22 @@
         end
       end
     end
+
+    context 'with invalid params' do
+      let(:user) { member_giver.user }
+      let(:referer) { "/transfers/new?destination_account_id=#{member_taker.account.id}" }
+
+      before do
+        request.env["HTTP_REFERER"] = referer
+      end
+
+      it 'does not create any Transfer and redirects to :back if the amount is 0' do
+        expect {
+          post(:create, transfer: { amount: 0, destination: member_taker.account.id })
+        }.not_to change(Transfer, :count)
+
+        expect(response).to redirect_to(referer)
+      end
+    end
   end
 end