feat(medusa): Use query relation load strategy on Carts (#3984)

packages/medusa/src/models/cart.ts

@@ -216,7 +216,6 @@
  */
 
 import {
-  AfterLoad,
   BeforeInsert,
   Column,
   Entity,
@@ -226,7 +225,7 @@ import {
   ManyToMany,
   ManyToOne,
   OneToMany,
-  OneToOne,
+  OneToOne
 } from "typeorm"
 import { DbAwareColumn, resolveDbType } from "../utils/db-aware-column"
 import {
@@ -234,6 +233,8 @@ import {
   FeatureFlagDecorators,
 } from "../utils/feature-flag-decorators"
 
+import { SoftDeletableEntity } from "../interfaces/models/soft-deletable-entity"
+import { generateEntityId } from "../utils/generate-entity-id"
 import { Address } from "./address"
 import { Customer } from "./customer"
 import { Discount } from "./discount"
@@ -244,8 +245,6 @@ import { PaymentSession } from "./payment-session"
 import { Region } from "./region"
 import { SalesChannel } from "./sales-channel"
 import { ShippingMethod } from "./shipping-method"
-import { SoftDeletableEntity } from "../interfaces/models/soft-deletable-entity"
-import { generateEntityId } from "../utils/generate-entity-id"
 
 export enum CartType {
   DEFAULT = "default",
@@ -391,13 +390,6 @@ export class Cart extends SoftDeletableEntity {
   gift_card_total?: number
   gift_card_tax_total?: number
 
-  @AfterLoad()
-  private afterLoad(): void {
-    if (this.payment_sessions) {
-      this.payment_session = this.payment_sessions.find((p) => p.is_selected)!
-    }
-  }
-
   @BeforeInsert()
   private beforeInsert(): void {
     this.id = generateEntityId(this.id, "cart")

packages/medusa/src/models/shipping-method.ts

@@ -11,17 +11,17 @@ import {
   PrimaryColumn,
 } from "typeorm"
 
+import TaxInclusivePricingFeatureFlag from "../loaders/feature-flags/tax-inclusive-pricing"
+import { DbAwareColumn } from "../utils/db-aware-column"
+import { FeatureFlagColumn } from "../utils/feature-flag-decorators"
+import { generateEntityId } from "../utils/generate-entity-id"
 import { Cart } from "./cart"
 import { ClaimOrder } from "./claim-order"
-import { DbAwareColumn } from "../utils/db-aware-column"
 import { Order } from "./order"
 import { Return } from "./return"
 import { ShippingMethodTaxLine } from "./shipping-method-tax-line"
 import { ShippingOption } from "./shipping-option"
 import { Swap } from "./swap"
-import { generateEntityId } from "../utils/generate-entity-id"
-import { FeatureFlagColumn } from "../utils/feature-flag-decorators"
-import TaxInclusivePricingFeatureFlag from "../loaders/feature-flags/tax-inclusive-pricing"
 
 @Check(
   `"claim_order_id" IS NOT NULL OR "order_id" IS NOT NULL OR "cart_id" IS NOT NULL OR "swap_id" IS NOT NULL OR "return_id" IS NOT NULL`
@@ -56,7 +56,7 @@ export class ShippingMethod {
   @Column({ nullable: true })
   cart_id: string
 
-  @ManyToOne(() => Cart)
+  @ManyToOne(() => Cart, (cart) => cart.shipping_methods)
   @JoinColumn({ name: "cart_id" })
   cart: Cart
 

packages/medusa/src/models/tax-rate.ts

@@ -10,11 +10,11 @@ import {
 
 import { BaseEntity } from "../interfaces/models/base-entity"
 import { DbAwareColumn } from "../utils/db-aware-column"
+import { generateEntityId } from "../utils/generate-entity-id"
 import { Product } from "./product"
 import { ProductType } from "./product-type"
 import { Region } from "./region"
 import { ShippingOption } from "./shipping-option"
-import { generateEntityId } from "../utils/generate-entity-id"
 
 @Entity()
 export class TaxRate extends BaseEntity {
@@ -30,7 +30,7 @@ export class TaxRate extends BaseEntity {
   @Column()
   region_id: string
 
-  @ManyToOne(() => Region)
+  @ManyToOne(() => Region, (region) => region.tax_rates)
   @JoinColumn({ name: "region_id" })
   region: Region