Centralize entry naming (#2454)

* Centralize entry naming

* Lint fixes, code style

test/models/trade_test.rb

@@ -0,0 +1,23 @@
+require "test_helper"
+
+class TradeTest < ActiveSupport::TestCase
+  test "build_name generates buy trade name" do
+    name = Trade.build_name("buy", 10, "AAPL")
+    assert_equal "Buy 10.0 shares of AAPL", name
+  end
+
+  test "build_name generates sell trade name" do
+    name = Trade.build_name("sell", 5, "MSFT")
+    assert_equal "Sell 5.0 shares of MSFT", name
+  end
+
+  test "build_name handles absolute value for negative quantities" do
+    name = Trade.build_name("sell", -5, "GOOGL")
+    assert_equal "Sell 5.0 shares of GOOGL", name
+  end
+
+  test "build_name handles decimal quantities" do
+    name = Trade.build_name("buy", 0.25, "BTC")
+    assert_equal "Buy 0.25 shares of BTC", name
+  end
+end