fix(medusa): gift card values & taxes are calculated correctly (#2777)

* chore: tax_rate is added to giftcards

* chore: minor

* chore: update gift card tax calculations to look at giftCard.tax_rate

* chore: gift card transactions use tax rate from gift card for legacy

* fix: gift cart total check for transaction should check the length

* chore: use tax exclusive cost + use giftcard tax rate for gctransactions + refactor

* chore: fix integration test

* chore: address issues brought up in comments

* chore: move gift card creation as a part of order service on order placed

* chore: add type handling for gift card creation

* chore: fix specs

* chore: use taxLines to calculate tax of a gift card

* chore: specs for line items containing gift cards and without

* chore: add integration specs + fix tax rate bug

* chore: round totaling + add GC application specs

* chore: cleanup trialables

* chore: write migration script to backfill gift cards with null tax_rate

* chore: update legacy totals service for gift cards

* chore: add changeset

* chore: address PR review changes

* chore: fix tests based on new totals calc

* chore: address review comments

Co-authored-by: adrien2p <adrien.deperetti@gmail.com>
Co-authored-by: Oliver Windall Juhl <59018053+olivermrbl@users.noreply.github.com>

packages/medusa/src/models/gift-card.ts

@@ -50,6 +50,9 @@ export class GiftCard extends SoftDeletableEntity {
   })
   ends_at: Date
 
+  @Column({ type: "real", nullable: true })
+  tax_rate: number | null
+
   @DbAwareColumn({ type: "jsonb", nullable: true })
   metadata: Record<string, unknown>
 
@@ -108,6 +111,10 @@ export class GiftCard extends SoftDeletableEntity {
  *     description: "The time at which the Gift Card can no longer be used."
  *     type: string
  *     format: date-time
+ *   tax_rate:
+ *     description: The gift cards's tax rate that will be applied on calculating totals
+ *     type: number
+ *     example: 0
  *   created_at:
  *     type: string
  *     description: "The date with timezone at which the resource was created."