Fix income summary totals (#759)

app/models/transaction.rb

@@ -9,8 +9,8 @@ class Transaction < ApplicationRecord
 
   monetize :amount
 
-  scope :inflows, -> { where("amount > 0") }
-  scope :outflows, -> { where("amount < 0") }
+  scope :inflows, -> { where("amount <= 0") }
+  scope :outflows, -> { where("amount > 0") }
   scope :active, -> { where(excluded: false) }
   scope :with_converted_amount, ->(currency = Current.family.currency) {
     # Join with exchange rates to convert the amount to the given currency

test/models/transaction_test.rb

@@ -1,4 +1,14 @@
 require "test_helper"
 
 class TransactionTest < ActiveSupport::TestCase
+  # See: https://github.com/maybe-finance/maybe/wiki/vision#signage-of-money
+  test "negative amounts are inflows, positive amounts are outflows to an account" do
+    inflow_transaction = transactions(:checking_four)
+    outflow_transaction = transactions(:checking_five)
+
+    assert inflow_transaction.amount < 0
+    assert outflow_transaction.amount >= 0
+    assert Transaction.inflows.include? inflow_transaction
+    assert Transaction.outflows.include? outflow_transaction
+  end
 end