Spree Common Shipping Method Splitter

A Spree extension that keeps items of different shipping categories in a single shipment as long as the categories have at least one shipping method in common.

Spree's default stock splitter Spree::Stock::Splitter::ShippingCategory always puts items of different shipping categories into separate shipments. That is the right behaviour for categories that cannot travel together (refrigerated / frozen / hazardous), but it also splits carts whose categories merely differ in the methods they accept, and the customer ends up paying shipping twice.

A typical example is a small, light product that can be sent either by parcel or by a cheap mail service, while every other product can only be sent by parcel:

With the default splitter, a cart containing one product of each category becomes two shipments (Parcel + Mail). With this extension the cart stays in one shipment, and Spree's existing Spree::Stock::Package#shipping_methods (the intersection of the shipping methods of all categories in the package) offers only Parcel.

Categories that share no shipping method are still split into separate shipments exactly as before:

• Refrigerated + Either → one shipment, Refrigerated delivery only
• Refrigerated + Frozen → two shipments (no common method)
• Refrigerated + Frozen + Either → three shipments (no method common to all categories; packages are never merged partially)

No configuration is required: the decision is made from the shipping method data of the store.

1. Add this extension to your Gemfile:

   gem 'spree_common_shipping_method_splitter', github: 'be-agile/spree_common_shipping_method_splitter'

2. Then bundle install:

   bundle install

The extension replaces Spree::Stock::Splitter::ShippingCategory in Spree.stock_splitters with Spree::Stock::Splitter::CommonShippingMethod at the same position, so the order of the remaining splitters (Backordered, Digital) is unchanged.

This extension is available as open source under the terms of either:

• GNU Affero General Public License v3.0 or later (AGPL-3.0-or-later)
• BSD 3-Clause License

be agile Co., Ltd.