perf(transactions): preload new form options (#2189)

* perf(transactions): preload new form options

* refactor(transactions): reuse new form account scope

test/controllers/transactions_controller_test.rb

@@ -462,6 +462,56 @@ end
     end
   end
 
+  test "new preloads transaction form option data" do
+    family = families(:empty)
+    user = users(:empty)
+    sign_in user
+
+    manual_account_ids = []
+    4.times do |idx|
+      account = family.accounts.create!(
+        name: "Manual Account #{idx}",
+        balance: 0,
+        currency: "USD",
+        accountable: Depository.new
+      )
+      assert Account.manual.active.exists?(id: account.id), "Account should be included in the manual active scope"
+      manual_account_ids << account.id
+      family.categories.create!(
+        name: "Category #{idx}",
+        color: "#000000",
+        lucide_icon: "shapes"
+      )
+      family.merchants.create!(name: "Merchant #{idx}")
+      family.tags.create!(name: "Tag #{idx}")
+    end
+
+    inaccessible_account = families(:dylan_family).accounts.create!(
+      name: "Other Family Account",
+      balance: 0,
+      currency: "EUR",
+      accountable: Depository.new
+    )
+
+    queries = capture_sql_queries { get new_transaction_url }
+
+    assert_response :success
+    assert_select "input[name='entry[account_id]']"
+    assert_select "input[name='entry[entryable_attributes][category_id]']"
+    assert_select "input[name='entry[entryable_attributes][merchant_id]']"
+    assert_select "form[data-transaction-form-account-currencies-value]" do |forms|
+      account_currencies = JSON.parse(forms.first["data-transaction-form-account-currencies-value"])
+      manual_account_ids.each do |account_id|
+        assert_equal "USD", account_currencies[account_id.to_s]
+      end
+      assert_nil account_currencies[inaccessible_account.id.to_s]
+    end
+
+    assert_empty queries.grep(/FROM "account_providers" WHERE "account_providers"\."account_id" =/)
+    assert_operator queries.grep(/FROM "active_storage_attachments" WHERE "active_storage_attachments"\."record_id" =/).size, :<=, 1
+    assert_operator queries.grep(/SELECT "categories"\.\* FROM "categories" WHERE "categories"\."family_id" =/).size, :<=, 1
+  end
+
   test "unlock clears import_locked flag" do
     family = families(:empty)
     sign_in users(:empty)
@@ -634,4 +684,21 @@ end
     created_entry = Entry.order(:created_at).last
     assert_nil created_entry.transaction.extra["exchange_rate"]
   end
+
+  private
+    def capture_sql_queries
+      queries = []
+      callback = lambda do |_name, _started, _finished, _unique_id, payload|
+        next if payload[:cached]
+        next if %w[SCHEMA TRANSACTION].include?(payload[:name])
+
+        queries << payload[:sql].squish
+      end
+
+      ActiveSupport::Notifications.subscribed(callback, "sql.active_record") do
+        yield
+      end
+
+      queries
+    end
 end