Openfoodnetwork: When editing an adjustment, the tax type displayed is not the one selected previously

[RachL]

Description

When you edit an adjustment of an order the tax rate displayed is not the tax rate that has been selected previously.

Steps to Reproduce

1. Add an adjustment to an order and select a tax type
2. Save
3. Edit the adjustment again, see that the tax rate displayed is not the previous one: often it is the "remove tax" tax type

Animated Gif/Screenshot

In this screenshot the 20% tax is displayed but we can clearly see that the tax rate that was calculated to get to 0,05 cents was not 20%

Severity

bug-s3: a feature is broken but there is a workaround

Your Environment

• Version used: v2.9.8
• Browser name and version: Firefox 73
• Operating System and version (desktop or mobile): Desktop

[luisramos0]

there must be a problem in the form or controller setting the tax_rate_id used app/views/spree/admin/adjustments/_edit_form.html.haml and probably set in app/controllers/spree/admin/adjustments_controller.rb

I am tagging good-first-issue, should be easy for a dev with experience with rails.

[luchiago]

Can I work on this?

[luisramos0]

yes! thanks!!

[luchiago]

@luisramos0 I found two things
The tax rate that is been used during the editing is correct. However, there is a config that is changing one boolean variable of the selected tax rate.

34: def compute_line_item(line_item)
 => 35:   if line_item.tax_category == rate.tax_category
    36:     if rate.included_in_price
    37:       deduced_total_by_rate(line_item.total, rate)
    38:     else
    39:       round_to_two_places(line_item.total * rate.amount)
    40:     end
    41:   else
    42:     0
    43:   end
    44: end

[16] pry(#<Spree::Calculator::DefaultTax>)> rate
=> #<Spree::TaxRate id: 1, amount: #<BigDecimal:564e41ba0be0,'0.2E0',9(18)>, zone_id: 3, tax_category_id: 1, created_at: "2020-06-07 00:38:33", updated_at: "2020-06-07 00:50:35", included_in_price: true, name: "Teste", show_rate_in_label: true, deleted_at: nil>
[17] pry(#<Spree::Calculator::DefaultTax>)> TaxRate.find_by_id(line_item.tax_category_id)
=> #<Spree::TaxRate id: 1, amount: #<BigDecimal:564e3ea59528,'0.2E0',9(18)>, zone_id: 3, tax_category_id: 1, created_at: "2020-06-07 00:38:33", updated_at: "2020-06-07 00:50:35", included_in_price: false, name: "Teste", show_rate_in_label: true, deleted_at: nil>

As you can se, the rate is the selected tax rate (in the case, 20%), but the attribute included_in_price was changed, causing the incorrect value

My guess is this configuration on this method from tax_rate_decorator.rb used on adjustments_controller.rb

    def compute_tax(amount)
      line_item = LineItem.new quantity: 1
      line_item.tax_category = tax_category
      line_item.define_singleton_method(:price) { amount }

      # Tax on adjustments (represented by the included_tax field) is always inclusive of
      # tax. However, there's nothing to stop an admin from setting one up with a tax rate
      # that's marked as not inclusive of tax, and that would result in the DefaultTax
      # calculator generating a slightly incorrect value. Therefore, we treat the tax
      # rate as inclusive of tax for the calculations below, regardless of its original
      # setting.
      with_tax_included_in_price do
        calculator.compute line_item
      end
    end

    private

    def with_tax_included_in_price
      old_included_in_price = included_in_price

      self.included_in_price = true
      calculator.calculable.included_in_price = true

      result = yield
    ensure
      self.included_in_price = old_included_in_price
      calculator.calculable.included_in_price = old_included_in_price

      result
    end
  end

What do you think?

[luisramos0]

I dont think there's an incorrect value, do you?
The fix to this issue should just change the drop down selection to the correct tax rate.
Maybe just something wrong with this line?
= select_tag :tax_rate_id, options_from_collection_for_select(Spree::TaxRate.all, :id, :name, @tax_rate_id), prompt: t(:remove_tax), class: 'select2 fullwidth'

[luchiago]

Hmmm, I will check this @luisramos0

[luchiago]

[luisramos0]

[luchiago]

[luisramos0]

[luisramos0]

[RachL]

[sigmundpetersen]

[luchiago]

[RachL]

[filipefurtad0]

[RachL]

[filipefurtad0]