README

Magento merges every applied discount into one totals row, "Discount (...)", whose label is built from rule labels or, worse, from internal rule descriptions. This module shows one totals line per sales rule instead, on every surface where totals appear, and never shows a rule description or internal rule name to the customer.

One line per rule in cart, checkout, order confirmation email, invoice email and PDF, credit memo email and PDF, My Account order view and admin order view.
Per-rule amounts are stored when the order is placed (core keeps only coupon_code, discount_description and applied_rule_ids).
The lines always add up to Magento's discount total, to the cent.
Frontend-agnostic: this base package holds the data, storage, label rule, resolvers and the plain-text totals rows for all sales documents. The storefront renderers are separate packages (see below).

Packages

Package	Role
`pixelperfectat/magento2-module-discount-lines`	This package: data, storage, label rule, sales documents, configuration
`pixelperfectat/magento2-module-discount-lines-hyva-checkout`	Hyvä Checkout price summary
`pixelperfectat/magento2-module-discount-lines-hyva-theme`	Hyvä default theme cart page
`pixelperfectat/magento2-module-discount-lines-luma`	Luma cart summary and checkout sidebar
`pixelperfectat/magento2-module-discount-lines-amasty-promo`	Amasty Free Gift rules as gift lines
`pixelperfectat/magento2-module-discount-lines-mageplaza-giftcard`	Mageplaza gift cards as masked gift card lines

Requirements

PHP 8.3+
Magento 2.4.7+ or Mage-OS (magento/module-sales-rule, module-quote, module-sales)

Installation

composer require pixelperfectat/magento2-module-discount-lines
bin/magento setup:upgrade

Add the renderer package for your frontend (Luma, Hyvä theme, Hyvä Checkout) and, if you use them, the Amasty or Mageplaza adapter.

Configuration

Stores > Configuration > Sales > Discount Lines. All settings have store-view scope.

Path	Default	Description
`pp_discount_lines/general/enabled`	`1`	Master switch. When off, every surface shows the core `discount` row.
`pp_discount_lines/display/variant`	`B`	Storefront variant `A`, `B`, `C` or `D` (cart, drawer data, checkout).
`pp_discount_lines/documents/email_icon`	`0`	Flag for a small icon next to discount lines in emails (see note below).

documents/email_icon is read through ConfigInterface::isEmailIconEnabled() and the icon files ship in view/frontend/web/images/ (coupon.png, promotion.png); the plain-text rows of this package do not render icons themselves, a sales-email module that follows the contract below does.

Display variants

Sales documents (email, PDF, My Account, admin) always use plain text, for example "Coupon CODE -2.25". The variants apply to the storefront renderers:

Variant	Look
A	Label with the coupon chip below
B	Chip as the label (default)
C	Grouped block with a "You save" sum
D	Quiet icon and monospace

Label rule

Kind	Label	Amount column
`coupon`	the coupon code	-amount
`automatic`	the rule's store label for the order's store view, else the default store label, else a translated "Discount"	-amount
`free_shipping`	coupon: the code; automatic: store label or translated "Free shipping"	-shipping discount, or "Free"
`gift`	adapter: the coupon code	"Gift" when the gift carries no money, otherwise the amount
`gift_card`	adapter: "Gift card ••••1234" (masked, last 4)	-amount

The rule description and the rule name are never used. Labels are snapshotted when the order is placed, so a rule that is deleted or relabelled later does not change existing orders.

How it works

Quote address storage at collect time. After the totals of an address are collected, the per-rule lines are resolved and stored on the quote address (quote_address.pp_discount_lines). Resolution is one generic rule resolver (RuleDiscountResolver, reads core's per-rule discount breakdown of the address, so it covers every simple_action including by_percent, by_fixed, cart_fixed and buy_x_get_y) plus a free shipping resolver, both in a composite (CompositeResolver) that is the extension point: adapters add their own named resolvers to it through di.xml. The invariant is that the lines sum to the address discount; rounding differences of up to one cent per line are absorbed by the largest line, a larger unattributed remainder becomes a generic "Discount" line instead of being misattributed to a rule, and lines above the discount (or disagreeing between order and base currency) are dropped so the core row is shown with the plain title "Discount". A failed collect clears the stored lines.
Totals segment extension attribute. A plugin on CartTotalRepositoryInterface adds the lines to the discount total segment as extension_attributes.discount_lines and replaces the segment title (which carries the rule description in core). When a quote has only zero-value lines (a gift or free shipping), a zero discount segment is added so renderers still get the lines. Stored lines that do not add up to the segment value are not exposed (the title is the plain "Discount"). The cart page and checkout renderers read this attribute.
Persistence at order placement. On sales_model_service_quote_submit_success the lines are written to the table pp_discount_line: order-level lines plus item-level per-rule amounts (these make the credit memo split possible). When a discounted order has no attributable lines, one generic automatic "Discount" line for the full amount is stored, so the order never falls back to the core label.
Totals-block plugin. A plugin on Magento\Sales\Block\Order\Totals (order, invoice and credit memo blocks, so emails, My Account and the admin) replaces the core discount row by one row per line. An invoice scales the stored lines to the invoice discount; a credit memo splits each rule in proportion to the refunded quantities and the largest line absorbs the rounding remainder, so the lines always equal the document's discount total. Stored order lines that do not add up to the order discount are scaled to it. When a document gets no line although the order has lines (for example a shipping-only refund), the core row keeps its amount and gets the plain label "Discount".
Shipping label. Core appends the discount description (the rule description) to the shipping row label when a document has no discount row and no coupon code (zero-discount gift or free shipping orders, their invoices and credit memos: "Shipping & Handling (…)"). While the module is enabled, the plugin restores the plain "Shipping & Handling" label on every order, invoice and credit memo; a coupon code in the label is kept.
PDF total. A PDF total model for discount (etc/pdf.xml) prints one line per rule in invoice and credit memo PDFs; zero-amount gift and free shipping lines print "Gift" / "Free" in the amount column.

Orders without stored lines (placed before the module was installed, or while it was disabled) are never touched and keep the merged core row.

Contract with the sales-email module

Each discount line is its own totals row in the standard Magento totals blocks (Magento\Sales\Block\Order\Totals and descendants, invoice/creditmemo totals, PDF totals):

totals row code: pp_discount_line_<n> (n = 0-based position), replacing the core discount row.
the row (\Magento\Framework\DataObject) carries the data key discount_line:

discount_line = {
  kind:        "coupon" | "automatic" | "gift" | "free_shipping" | "gift_card",
  rule_id:     int|null,      // null for gift_card
  code:        string|null,   // coupon / gift-card code (masked for gift_card)
  label:       string,        // already resolved by the label rule, safe to show
  amount:      float,         // order currency, positive number = discount
  base_amount: float
}

Row label and value stay populated (value negative, as core), so any template that ignores discount_line still prints a correct plain row → works without the email module.
Without this module the email module renders the core discount row.
Neither module requires the other in composer.json (at most suggest).
Builder's call: expose the same array on the cart totals extension attributes (TotalSegmentExtensionInterface) for the storefront renderers.

Notes for consumers:

Detect a discount line by the discount_line data key on any totals row, not by the row code: the row codes of this package are pp_discount_line_<n>, while gift card rows of the Mageplaza adapter keep Mageplaza's own codes (gift_card / gift_card_<n>) and carry discount_line with kind gift_card.
A row without discount_line is a core row; the discount row of an order with stored lines carries the plain label "Discount", never the rule description.
DocumentLineLabelInterface gives the plain label (format()), the signed value (value()) and the text printed in place of a zero amount (amountText(): "Gift" / "Free").

Extending

Add a line kind or handle a custom simple_action by adding a named DiscountLineResolverInterface to the resolvers argument of CompositeResolver in di.xml. An entry that does not implement the interface is skipped and logged, never thrown.
All services are behind interfaces in Api/Service/ and bound by <preference>.
Colours and fonts of the storefront renderers are CSS custom properties in PixelPerfect_DiscountLines::css/discount-lines.css; override them on :root in your theme.

Known limits

Orders placed before the module was installed keep the merged core row; per-rule amounts are not rebuilt.
Existing carts show the core row until the next totals collect (any cart change or page load that collects totals).
If an item is added during a collect and core has no per-rule breakdown for it, that collect falls back to the core row; the next collect shows the lines again.
Per-rule amounts across several invoices of one order can drift by one cent per rule against the order lines; the discount total of every document is exact.
Multishipping is not supported in v1: multishipping orders bypass the persistence event and show the core row.
Stores that override sales/totals_sort must add the gift_card code when they use the Mageplaza adapter.
The default Hyvä theme discount block is replaced by the Hyvä theme renderer; customisations of that block must target pp.discount-lines instead.
Adapter-specific limits are listed in the adapter READMEs (Amasty over-attribution of gifts, Mageplaza's own gift card JSON).

Screenshots

Placeholder data only, in docs/screenshots/:

Development

composer install
composer check

composer check runs composer validate, PHP lint, PHP_CodeSniffer, PHPStan, PHPUnit and Infection mutation testing (fails below MSI 85 or covered-code MSI 90). Infection needs a coverage driver: enable pcov, or Xdebug with XDEBUG_MODE=coverage. composer infection runs the mutation tests on their own.

License

MIT, see LICENSE.

pixelperfectat / magento2-module-discount-lines

Package info

Security

Statistics