Maybe/test/models/balance_sheet_test.rb

require "test_helper"

class BalanceSheetTest < ActiveSupport::TestCase
  setup do
    @family = families(:empty)
  end

  test "calculates total assets" do
    assert_equal 0, BalanceSheet.new(@family).assets.total

    create_account(balance: 1000, accountable: Depository.new)
    create_account(balance: 5000, accountable: OtherAsset.new)
    create_account(balance: 10000, accountable: CreditCard.new) # ignored

    assert_equal 1000 + 5000, BalanceSheet.new(@family).assets.total
  end

  test "calculates total liabilities" do
    assert_equal 0, BalanceSheet.new(@family).liabilities.total

    create_account(balance: 1000, accountable: CreditCard.new)
    create_account(balance: 5000, accountable: OtherLiability.new)
    create_account(balance: 10000, accountable: Depository.new) # ignored

    assert_equal 1000 + 5000, BalanceSheet.new(@family).liabilities.total
  end

  test "calculates net worth" do
    assert_equal 0, BalanceSheet.new(@family).net_worth

    create_account(balance: 1000, accountable: CreditCard.new)
    create_account(balance: 50000, accountable: Depository.new)

    assert_equal 50000 - 1000, BalanceSheet.new(@family).net_worth
  end

  test "disabled accounts do not affect totals" do
    create_account(balance: 1000, accountable: CreditCard.new)
    create_account(balance: 10000, accountable: Depository.new)

    other_liability = create_account(balance: 5000, accountable: OtherLiability.new)
    other_liability.disable!

    assert_equal 10000 - 1000, BalanceSheet.new(@family).net_worth
    assert_equal 10000, BalanceSheet.new(@family).assets.total
    assert_equal 1000, BalanceSheet.new(@family).liabilities.total
  end

  test "calculates asset group totals" do
    create_account(balance: 1000, accountable: Depository.new)
    create_account(balance: 2000, accountable: Depository.new)
    create_account(balance: 3000, accountable: Investment.new)
    create_account(balance: 5000, accountable: OtherAsset.new)
    create_account(balance: 10000, accountable: CreditCard.new) # ignored

    asset_groups = BalanceSheet.new(@family).assets.account_groups

    assert_equal 3, asset_groups.size
    assert_equal 1000 + 2000, asset_groups.find { |ag| ag.name == "Cash" }.total
    assert_equal 3000, asset_groups.find { |ag| ag.name == "Investments" }.total
    assert_equal 5000, asset_groups.find { |ag| ag.name == "Other Assets" }.total
  end

  test "calculates liability group totals" do
    create_account(balance: 1000, accountable: CreditCard.new)
    create_account(balance: 2000, accountable: CreditCard.new)
    create_account(balance: 3000, accountable: OtherLiability.new)
    create_account(balance: 5000, accountable: OtherLiability.new)
    create_account(balance: 10000, accountable: Depository.new) # ignored

    liability_groups = BalanceSheet.new(@family).liabilities.account_groups

    assert_equal 2, liability_groups.size
    assert_equal 1000 + 2000, liability_groups.find { |ag| ag.name == "Credit Cards" }.total
    assert_equal 3000 + 5000, liability_groups.find { |ag| ag.name == "Other Liabilities" }.total
  end

  private
    def create_account(attributes = {})
      account = @family.accounts.create! name: "Test", currency: "USD", **attributes
      account
    end
end