Remove user address reference when removing address from the address

[SamuelMartini]

Description

The address book should provide the user the ability to manage all his addresses.

ship_address_id and bill_address_id are persisted on the Spree::User record after transitioning from address: Spree::User#persist_order_address.

solidus/core/app/models/concerns/spree/user_address_book.rb

Lines 70 to 77 in 18f6ebc

	def persist_order_address(order)
	if order.ship_address
	address = save_in_address_book(
	order.ship_address.attributes,
	Spree::Config.automatic_default_address
	)
	self.ship_address_id = address.id if address && address.persisted?
	end

These address fields are used to assign user default addresses to the order before transitioning to address: Spree::Order#assign_default_user_addresses.

solidus/core/app/models/spree/order.rb

Lines 716 to 726 in d0d1e3d

	def assign_default_user_addresses
	if user
	bill_address = (user.bill_address || user.default_address)
	ship_address = (user.ship_address || user.default_address)
	# this is one of 2 places still using User#bill_address
	self.bill_address ||= bill_address if bill_address.try!(:valid?)
	# Skip setting ship address if order doesn't have a delivery checkout step
	# to avoid triggering validations on shipping address
	self.ship_address ||= ship_address if ship_address.try!(:valid?) && checkout_steps.include?("delivery")
	end
	end

Currently, when a user empties his address book the user record still has the ship_address_id and bill_address_id references.
In the address checkout step because of assign_default_user_addresses the order addresses are filled with addresses linked on the user record.

As a user I expect that when I empty my address book no address will be shown during my next checkout.

As a developer I expect to use the address book to provide the user full management capability on his addresses.

This commit removes the address reference from the user record when an address is removed from the address book.

Checklist:

• I have followed Pull Request guidelines
• I have added a detailed description into each commit message
• I have added tests to cover this change (if needed)

[spaghetticode]

@SamuelMartini thank you for this fix! I left a minor note on tests, hope it makes sense

[spaghetticode]

I think that besides all these cases when the attributes match and so they are then changed to nil, it would be nice to have at least one test for the other scenarios when they don't match and they are not changed... what do you think?

[SamuelMartini]

Hey @spaghetticode, thank you for the comment!
Added example when the address does not match any user addresses: https://github.com/solidusio/solidus/pull/3482/files#diff-e930e6c49d94b00d1756dfaf242e4d68R252-R264

[spaghetticode]

@SamuelMartini thank you 👍