Use resolver for trade builder

app/models/security/resolver.rb

@@ -1,6 +1,6 @@
 class Security::Resolver
   def initialize(symbol, exchange_operating_mic: nil, country_code: nil)
-    @symbol = symbol
+    @symbol = validate_symbol!(symbol)
     @exchange_operating_mic = exchange_operating_mic
     @country_code = country_code
   end
@@ -22,6 +22,11 @@ class Security::Resolver
   private
     attr_reader :symbol, :exchange_operating_mic, :country_code
 
+    def validate_symbol!(symbol)
+      raise ArgumentError, "Symbol is required and cannot be blank" if symbol.blank?
+      symbol.strip.upcase
+    end
+
     def offline_security
       security = Security.find_or_initialize_by(
         ticker: symbol,

app/models/trade_builder.rb

@@ -1,8 +1,6 @@
 class TradeBuilder
   include ActiveModel::Model
 
-  Error = Class.new(StandardError)
-
   attr_accessor :account, :date, :amount, :currency, :qty,
                 :price, :ticker, :manual_ticker, :type, :transfer_account_id
 
@@ -131,13 +129,9 @@ class TradeBuilder
     def security
       ticker_symbol, exchange_operating_mic = ticker.present? ? ticker.split("|") : [ manual_ticker, nil ]
 
-      unless ticker_symbol.present?
-        raise Error, "Ticker symbol is required to create a trade"
-      end
-
-      Security.find_or_create_by!(
-        ticker: ticker_symbol,
+      Security::Resolver.new(
+        ticker_symbol,
         exchange_operating_mic: exchange_operating_mic
-      )
+      ).resolve
     end
 end

test/models/security/resolver_test.rb

@@ -72,8 +72,7 @@ class Security::ResolverTest < ActiveSupport::TestCase
   end
 
   test "returns nil when symbol blank" do
-    assert_no_difference "Security.count" do
-      assert_nil Security::Resolver.new(nil).resolve
-    end
+    assert_raises(ArgumentError) { Security::Resolver.new(nil).resolve }
+    assert_raises(ArgumentError) { Security::Resolver.new("").resolve }
   end
 end