sure/test/models/trade_test.rb

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

  test "price scale is preserved at 10 decimal places" do
    security = Security.create!(ticker: "TEST", exchange_operating_mic: "XNAS")

    # up to 10 decimal places — should persist exactly
    precise_price = BigDecimal("12.3456789012")
    trade = Trade.create!(
      security: security,
      price: precise_price,
      qty: 10000,
      currency: "USD",
      investment_activity_label: "Buy"
    )

    trade.reload

    assert_equal precise_price, trade.price
  end

  test "price is rounded to 10 decimal places" do
    security = Security.create!(ticker: "TEST", exchange_operating_mic: "XNAS")

    # over 10 decimal places — will be rounded
    price_with_too_many_decimals = BigDecimal("1.123456789012345")
    trade = Trade.create!(
      security: security,
      price: price_with_too_many_decimals,
      qty: 1,
      currency: "USD",
      investment_activity_label: "Buy"
    )

    trade.reload

    assert_equal BigDecimal("1.1234567890"), trade.price
  end
end