fix(customer): Unique constraint on customer email (#7439)

**What**
Prevent creating multiple customers with the same email

packages/modules/customer/src/models/address.ts

@@ -1,10 +1,13 @@
 import { DAL } from "@medusajs/types"
-import { Searchable, generateEntityId } from "@medusajs/utils"
+import {
+  createPsqlIndexStatementHelper,
+  generateEntityId,
+  Searchable,
+} from "@medusajs/utils"
 import {
   BeforeCreate,
   Cascade,
   Entity,
-  Index,
   ManyToOne,
   OnInit,
   OptionalProps,
@@ -15,22 +18,27 @@ import Customer from "./customer"
 
 type OptionalAddressProps = DAL.EntityDateColumns // TODO: To be revisited when more clear
 
-export const UNIQUE_CUSTOMER_SHIPPING_ADDRESS =
-  "IDX_customer_address_unique_customer_shipping"
-export const UNIQUE_CUSTOMER_BILLING_ADDRESS =
-  "IDX_customer_address_unique_customer_billing"
+const CustomerAddressUniqueCustomerShippingAddress =
+  createPsqlIndexStatementHelper({
+    name: "IDX_customer_address_unique_customer_shipping",
+    tableName: "customer_address",
+    columns: "customer_id",
+    unique: true,
+    where: '"is_default_shipping" = true',
+  })
+
+const CustomerAddressUniqueCustomerBillingAddress =
+  createPsqlIndexStatementHelper({
+    name: "IDX_customer_address_unique_customer_billing",
+    tableName: "customer_address",
+    columns: "customer_id",
+    unique: true,
+    where: '"is_default_billing" = true',
+  })
 
 @Entity({ tableName: "customer_address" })
-@Index({
-  name: UNIQUE_CUSTOMER_SHIPPING_ADDRESS,
-  expression:
-    'create unique index "IDX_customer_address_unique_customer_shipping" on "customer_address" ("customer_id") where "is_default_shipping" = true',
-})
-@Index({
-  name: UNIQUE_CUSTOMER_BILLING_ADDRESS,
-  expression:
-    'create unique index "IDX_customer_address_unique_customer_billing" on "customer_address" ("customer_id") where "is_default_billing" = true',
-})
+@CustomerAddressUniqueCustomerShippingAddress.MikroORMIndex()
+@CustomerAddressUniqueCustomerBillingAddress.MikroORMIndex()
 export default class Address {
   [OptionalProps]: OptionalAddressProps
 

packages/modules/customer/src/models/customer.ts

@@ -1,5 +1,10 @@
 import { DAL } from "@medusajs/types"
-import { DALUtils, Searchable, generateEntityId } from "@medusajs/utils"
+import {
+  createPsqlIndexStatementHelper,
+  DALUtils,
+  generateEntityId,
+  Searchable,
+} from "@medusajs/utils"
 import {
   BeforeCreate,
   Cascade,
@@ -7,8 +12,8 @@ import {
   Entity,
   Filter,
   ManyToMany,
-  OnInit,
   OneToMany,
+  OnInit,
   OptionalProps,
   PrimaryKey,
   Property,
@@ -22,8 +27,16 @@ type OptionalCustomerProps =
   | "addresses"
   | DAL.SoftDeletableEntityDateColumns
 
+const CustomerUniqueEmail = createPsqlIndexStatementHelper({
+  tableName: "customer",
+  columns: ["email", "has_account"],
+  unique: true,
+  where: "deleted_at IS NULL",
+})
+
 @Entity({ tableName: "customer" })
 @Filter(DALUtils.mikroOrmSoftDeletableFilterOptions)
+@CustomerUniqueEmail.MikroORMIndex()
 export default class Customer {
   [OptionalProps]?: OptionalCustomerProps