feat: add hasMany flag to enforce in app link uniqueness (#12039)

* feat: add createMultiple flag to enforce inApp link uniqueness

* changes

* mocks

* default

* many to many

---------

Co-authored-by: Carlos R. L. Rodrigues <rodrigolr@gmail.com>

integration-tests/modules/__tests__/link-modules/define-link.spec.ts

@@ -46,7 +46,7 @@ medusaIntegrationTestRunner({
               entity: "Currency",
               primaryKey: "code",
               foreignKey: "currency_code",
-              isList: true,
+              hasMany: false,
               alias: "currency",
               args: {
                 methodSuffix: "Currencies",
@@ -59,7 +59,7 @@ medusaIntegrationTestRunner({
               primaryKey: "id",
               foreignKey: "region_id",
               alias: "region",
-              isList: false,
+              hasMany: false,
               args: {
                 methodSuffix: "Regions",
               },
@@ -90,9 +90,9 @@ medusaIntegrationTestRunner({
               serviceName: "region",
               entity: "Region",
               fieldAlias: {
-                currencies: {
+                currency: {
                   path: "currency_link.currency",
-                  isList: true,
+                  isList: false,
                   forwardArgumentsOnPath: ["currency_link.currency"],
                 },
               },
@@ -102,7 +102,7 @@ medusaIntegrationTestRunner({
                 primaryKey: "region_id",
                 foreignKey: "id",
                 alias: "currency_link",
-                isList: true,
+                isList: false,
               },
             },
           ],
@@ -147,7 +147,7 @@ medusaIntegrationTestRunner({
               entity: "ProductVariant",
               primaryKey: "id",
               foreignKey: "product_variant_id",
-              isList: true,
+              hasMany: false,
               alias: "product_variant",
               args: {
                 methodSuffix: "ProductVariants",
@@ -159,7 +159,7 @@ medusaIntegrationTestRunner({
               entity: "Region",
               primaryKey: "id",
               foreignKey: "region_id",
-              isList: false,
+              hasMany: false,
               alias: "region",
               args: {
                 methodSuffix: "Regions",
@@ -191,9 +191,9 @@ medusaIntegrationTestRunner({
               serviceName: "region",
               entity: "Region",
               fieldAlias: {
-                product_variants: {
+                product_variant: {
                   path: "product_variant_link.product_variant",
-                  isList: true,
+                  isList: false,
                   forwardArgumentsOnPath: [
                     "product_variant_link.product_variant",
                   ],
@@ -205,7 +205,7 @@ medusaIntegrationTestRunner({
                 primaryKey: "region_id",
                 foreignKey: "id",
                 alias: "product_variant_link",
-                isList: true,
+                isList: false,
               },
             },
           ],
@@ -253,7 +253,7 @@ medusaIntegrationTestRunner({
               entity: "Currency",
               primaryKey: "code",
               foreignKey: "currency_code",
-              isList: true,
+              hasMany: false,
               alias: "currency",
               args: {
                 methodSuffix: "Currencies",
@@ -265,7 +265,7 @@ medusaIntegrationTestRunner({
               entity: "Region",
               primaryKey: "id",
               foreignKey: "region_id",
-              isList: false,
+              hasMany: false,
               alias: "region",
               args: {
                 methodSuffix: "Regions",
@@ -297,9 +297,9 @@ medusaIntegrationTestRunner({
               serviceName: "region",
               entity: "Region",
               fieldAlias: {
-                currencies: {
+                currency: {
                   path: "currency_link.currency",
-                  isList: true,
+                  isList: false,
                   forwardArgumentsOnPath: ["currency_link.currency"],
                 },
               },
@@ -309,7 +309,7 @@ medusaIntegrationTestRunner({
                 primaryKey: "region_id",
                 foreignKey: "id",
                 alias: "currency_link",
-                isList: true,
+                isList: false,
               },
             },
           ],
@@ -353,7 +353,7 @@ medusaIntegrationTestRunner({
               entity: "Currency",
               primaryKey: "code",
               foreignKey: "currency_code",
-              isList: true,
+              hasMany: false,
               alias: "currency",
               args: {
                 methodSuffix: "Currencies",
@@ -365,7 +365,113 @@ medusaIntegrationTestRunner({
               entity: "Region",
               primaryKey: "id",
               foreignKey: "region_id",
-              isList: true,
+              hasMany: true,
+              alias: "region",
+              args: {
+                methodSuffix: "Regions",
+              },
+              deleteCascade: false,
+            },
+          ],
+          extends: [
+            {
+              serviceName: "currency",
+              entity: "Currency",
+              fieldAlias: {
+                regions: {
+                  path: "region_link.region",
+                  isList: true,
+                  forwardArgumentsOnPath: ["region_link.region"],
+                },
+              },
+              relationship: {
+                serviceName: "CurrencyCurrencyRegionRegionLink",
+                entity: "LinkCurrencyCurrencyRegionRegion",
+                primaryKey: "currency_code",
+                foreignKey: "code",
+                alias: "region_link",
+                isList: true,
+              },
+            },
+            {
+              serviceName: "region",
+              entity: "Region",
+              fieldAlias: {
+                currency: {
+                  path: "currency_link.currency",
+                  isList: false,
+                  forwardArgumentsOnPath: ["currency_link.currency"],
+                },
+              },
+              relationship: {
+                serviceName: "CurrencyCurrencyRegionRegionLink",
+                entity: "LinkCurrencyCurrencyRegionRegion",
+                primaryKey: "region_id",
+                foreignKey: "id",
+                alias: "currency_link",
+                isList: false,
+              },
+            },
+          ],
+        })
+      })
+
+      it("should generate a proper link with both sides using explicit isList=true", async () => {
+        const currencyLinks = CurrencyModule.linkable
+        const regionLinks = RegionModule.linkable
+
+        const link = defineLink(
+          {
+            linkable: currencyLinks.currency,
+            isList: true,
+          },
+          {
+            linkable: regionLinks.region,
+            isList: true,
+          }
+        )
+
+        const linkDefinition = MedusaModule.getCustomLinks()
+          .map((linkDefinition: any) => {
+            const definition = linkDefinition(
+              MedusaModule.getAllJoinerConfigs()
+            )
+            return definition.serviceName === link.serviceName && definition
+          })
+          .filter(Boolean)[0]
+
+        expect(link.serviceName).toEqual("CurrencyCurrencyRegionRegionLink")
+        expect(linkDefinition).toEqual({
+          serviceName: "CurrencyCurrencyRegionRegionLink",
+          isLink: true,
+          alias: [
+            {
+              name: ["currency_region"],
+              args: {
+                entity: "LinkCurrencyCurrencyRegionRegion",
+              },
+            },
+          ],
+          primaryKeys: ["id", "currency_code", "region_id"],
+          relationships: [
+            {
+              serviceName: "currency",
+              entity: "Currency",
+              primaryKey: "code",
+              foreignKey: "currency_code",
+              hasMany: true,
+              alias: "currency",
+              args: {
+                methodSuffix: "Currencies",
+              },
+              deleteCascade: false,
+            },
+            {
+              serviceName: "region",
+              entity: "Region",
+              primaryKey: "id",
+              foreignKey: "region_id",
+              hasMany: true,
               alias: "region",
               args: {
                 methodSuffix: "Regions",
@@ -415,6 +521,112 @@ medusaIntegrationTestRunner({
           ],
         })
       })
+
+      it("should generate a proper link with both sides using explicit isList=false", async () => {
+        const currencyLinks = CurrencyModule.linkable
+        const regionLinks = RegionModule.linkable
+
+        const link = defineLink(
+          {
+            linkable: currencyLinks.currency,
+            isList: false,
+          },
+          {
+            linkable: regionLinks.region,
+            isList: false,
+          }
+        )
+
+        const linkDefinition = MedusaModule.getCustomLinks()
+          .map((linkDefinition: any) => {
+            const definition = linkDefinition(
+              MedusaModule.getAllJoinerConfigs()
+            )
+            return definition.serviceName === link.serviceName && definition
+          })
+          .filter(Boolean)[0]
+
+        expect(link.serviceName).toEqual("CurrencyCurrencyRegionRegionLink")
+        expect(linkDefinition).toEqual({
+          serviceName: "CurrencyCurrencyRegionRegionLink",
+          isLink: true,
+          alias: [
+            {
+              name: ["currency_region"],
+              args: {
+                entity: "LinkCurrencyCurrencyRegionRegion",
+              },
+            },
+          ],
+          primaryKeys: ["id", "currency_code", "region_id"],
+          relationships: [
+            {
+              serviceName: "currency",
+              entity: "Currency",
+              primaryKey: "code",
+              foreignKey: "currency_code",
+              hasMany: false,
+              alias: "currency",
+              args: {
+                methodSuffix: "Currencies",
+              },
+              deleteCascade: false,
+            },
+            {
+              serviceName: "region",
+              entity: "Region",
+              primaryKey: "id",
+              foreignKey: "region_id",
+              hasMany: false,
+              alias: "region",
+              args: {
+                methodSuffix: "Regions",
+              },
+              deleteCascade: false,
+            },
+          ],
+          extends: [
+            {
+              serviceName: "currency",
+              entity: "Currency",
+              fieldAlias: {
+                region: {
+                  path: "region_link.region",
+                  isList: false,
+                  forwardArgumentsOnPath: ["region_link.region"],
+                },
+              },
+              relationship: {
+                serviceName: "CurrencyCurrencyRegionRegionLink",
+                entity: "LinkCurrencyCurrencyRegionRegion",
+                primaryKey: "currency_code",
+                foreignKey: "code",
+                alias: "region_link",
+                isList: false,
+              },
+            },
+            {
+              serviceName: "region",
+              entity: "Region",
+              fieldAlias: {
+                currency: {
+                  path: "currency_link.currency",
+                  isList: false,
+                  forwardArgumentsOnPath: ["currency_link.currency"],
+                },
+              },
+              relationship: {
+                serviceName: "CurrencyCurrencyRegionRegionLink",
+                entity: "LinkCurrencyCurrencyRegionRegion",
+                primaryKey: "region_id",
+                foreignKey: "id",
+                alias: "currency_link",
+                isList: false,
+              },
+            },
+          ],
+        })
+      })
     })
   },
 })

packages/core/modules-sdk/src/__mocks__/inventory-module.ts

@@ -21,5 +21,6 @@ export const InventoryModule = {
     },
   },
 
+  list: jest.fn(async () => []),
   softDelete: jest.fn(() => {}),
 }

packages/core/modules-sdk/src/__mocks__/inventory-stock-location-link.ts

@@ -65,5 +65,6 @@ export const InventoryStockLocationLink = {
       foreignKeyData?: string
     ) => {}
   ),
+  list: jest.fn(async () => []),
   softDelete: jest.fn(() => {}),
 }

packages/core/modules-sdk/src/__mocks__/product-inventory-link.ts

@@ -71,5 +71,6 @@ export const ProductInventoryLinkModule = {
       foreignKeyData?: string
     ) => {}
   ),
+  list: jest.fn(async () => []),
   softDelete: jest.fn(() => {}),
 }

packages/core/modules-sdk/src/__mocks__/product-module.ts

@@ -18,5 +18,6 @@ export const ProductModule = {
     alias: [],
   },
 
+  list: jest.fn(async () => []),
   softDelete: jest.fn(() => {}),
 }

packages/core/modules-sdk/src/__mocks__/stock-location-module.ts

@@ -18,5 +18,6 @@ export const StockLocationModule = {
     alias: [],
   },
 
+  list: jest.fn(async () => []),
   softDelete: jest.fn(() => {}),
 }

packages/core/modules-sdk/src/link.ts

@@ -389,7 +389,7 @@ export class Link {
       {
         linksToCreate: [string | string[], string, Record<string, unknown>?][]
         linksToValidateForUniqueness: {
-          filters: { [key: string]: string }[]
+          filters: { [key: string]: any }[]
           services: string[]
         }
       }
@@ -418,55 +418,51 @@ export class Link {
            */
           linksToValidateForUniqueness: {
             filters: [],
-            services: [],
+            services: relationships?.map((r) => r.serviceName) ?? [],
           },
         })
       }
 
-      relationships?.forEach((relationship) => {
+      /**
-        const linksToValidateForUniqueness = serviceLinks.get(
+       * When isList is set on false on the relationship, then it means
-          service.__definition.key
+       * we have a one-to-one or many-to-one relationship with the
-        )!.linksToValidateForUniqueness!
+       * other side and we have limit duplicate entries from other
+       * entity. For example:
+       *
+       * - A brand has a many to one relationship with a product.
+       * - A product can have only one brand. Aka (brand.isList = false)
+       * - A brand can have multiple products. Aka (products.isList = true)
+       *
+       * A result of this, we have to ensure that a product_id can only appear
+       * once in the pivot table that is used for tracking "brand<>products"
+       * relationship.
+       */
+      const linksToValidateForUniqueness = serviceLinks.get(
+        service.__definition.key
+      )!.linksToValidateForUniqueness!
 
-        linksToValidateForUniqueness.services.push(relationship.serviceName)
+      const modA = relationships?.[0]!
-
+      const modB = relationships?.[1]!
-        /**
+      if (!modA.hasMany || !modB.hasMany) {
-         * When isList is set on false on the relationship, then it means
+        if (!modA.hasMany && !modB.hasMany) {
-         * we have a one-to-one or many-to-one relationship with the
+          linksToValidateForUniqueness.filters.push({
-         * other side and we have limit duplicate entries from other
+            $or: [
-         * entity. For example:
+              { [modA.foreignKey]: link[moduleA][modA.foreignKey] },
-         *
+              { [modB.foreignKey]: link[moduleB][modB.foreignKey] },
-         * - A brand has a many to one relationship with a product.
+            ],
-         * - A product can have only one brand. Aka (brand.isList = false)
+          })
-         * - A brand can have multiple products. Aka (products.isList = true)
+        } else if (!modA.hasMany) {
-         *
+          linksToValidateForUniqueness.filters.push({
-         * A result of this, we have to ensure that a product_id can only appear
+            [modA.foreignKey]: { $ne: link[moduleA][modA.foreignKey] },
-         * once in the pivot table that is used for tracking "brand<>products"
+            [modB.foreignKey]: link[moduleB][modB.foreignKey],
-         * relationship.
+          })
-         */
+        } else if (!modB.hasMany) {
-        if (relationship.isList === false) {
+          linksToValidateForUniqueness.filters.push({
-          const otherSide = relationships.find(
+            [modB.foreignKey]: { $ne: link[moduleB][modB.foreignKey] },
-            (other) => other.foreignKey !== relationship.foreignKey
+            [modA.foreignKey]: link[moduleA][modA.foreignKey],
-          )
+          })
-          if (!otherSide) {
-            return
-          }
-
-          if (moduleBKey === otherSide.foreignKey) {
-            linksToValidateForUniqueness.filters.push({
-              [otherSide.foreignKey]: link[moduleB][moduleBKey],
-            })
-          } else {
-            primaryKeys.forEach((pk) => {
-              if (pk === otherSide.foreignKey) {
-                linksToValidateForUniqueness.filters.push({
-                  [otherSide.foreignKey]: link[moduleA][pk],
-                })
-              }
-            })
-          }
         }
-      })
+      }
 
       const pkValue =
         primaryKeys.length === 1

packages/core/types/src/modules-sdk/index.ts

@@ -209,7 +209,7 @@ export type ModuleJoinerConfig = Omit<
           isList?: boolean
         }
     > // alias for deeper nested relationships (e.g. { 'price': 'prices.calculated_price_set.amount' })
-    relationship: ModuleJoinerRelationship
+    relationship: Omit<ModuleJoinerRelationship, "hasMany">
   }[]
   serviceName?: string
   primaryKeys?: string[]
@@ -248,6 +248,11 @@ export declare type ModuleJoinerRelationship = JoinerRelationship & {
    * If true, the link joiner will cascade deleting the relationship
    */
   deleteCascade?: boolean
+  /**
+   * Allow multiple relationships to exist for this
+   * entity
+   */
+  hasMany?: boolean
 }
 
 export type ModuleExports<T = Constructor<any>> = {

packages/core/utils/src/modules-sdk/define-link.ts

@@ -85,6 +85,7 @@ type ModuleLinkableKeyConfig = {
   deleteCascade?: boolean
   primaryKey: string
   alias: string
+  hasMany?: boolean
   shortcut?: Shortcut | Shortcut[]
 }
 
@@ -125,8 +126,7 @@ function buildFieldAlias(fieldAliases?: Shortcut | Shortcut[]) {
 }
 
 function prepareServiceConfig(
-  input: DefineLinkInputSource | DefineReadOnlyLinkInputSource,
+  input: DefineLinkInputSource | DefineReadOnlyLinkInputSource
-  defaultOptions?: { isList?: boolean }
 ) {
   let serviceConfig = {} as ModuleLinkableKeyConfig
 
@@ -138,7 +138,8 @@ function prepareServiceConfig(
       alias: source.alias ?? camelToSnakeCase(source.field ?? ""),
       field: input.field ?? source.field,
       primaryKey: source.primaryKey,
-      isList: defaultOptions?.isList ?? false,
+      isList: false,
+      hasMany: false,
       deleteCascade: false,
       module: source.serviceName,
       entity: source.entity,
@@ -148,12 +149,15 @@ function prepareServiceConfig(
       ? input.linkable.toJSON()
       : input.linkable
 
+    const hasMany = !!input.isList
+
     serviceConfig = {
       key: source.linkable,
       alias: source.alias ?? camelToSnakeCase(source.field ?? ""),
       field: input.field ?? source.field,
       primaryKey: source.primaryKey,
-      isList: input.isList ?? defaultOptions?.isList ?? false,
+      isList: input.isList ?? false,
+      hasMany,
       deleteCascade: input.deleteCascade ?? false,
       module: source.serviceName,
       entity: source.entity,
@@ -184,8 +188,8 @@ export function defineLink(
   rightService: DefineLinkInputSource | DefineReadOnlyLinkInputSource,
   linkServiceOptions?: ExtraOptions | ReadOnlyExtraOptions
 ): DefineLinkExport {
-  const serviceAObj = prepareServiceConfig(leftService, { isList: true })
+  const serviceAObj = prepareServiceConfig(leftService)
-  const serviceBObj = prepareServiceConfig(rightService, { isList: false })
+  const serviceBObj = prepareServiceConfig(rightService)
 
   if (linkServiceOptions?.readOnly) {
     return defineReadOnlyLink(
@@ -374,7 +378,7 @@ ${serviceBObj.module}: {
             methodSuffix: serviceAMethodSuffix,
           },
           deleteCascade: serviceAObj.deleteCascade,
-          isList: serviceAObj.isList,
+          hasMany: serviceAObj.hasMany,
         },
         {
           serviceName: serviceBObj.module,
@@ -386,7 +390,7 @@ ${serviceBObj.module}: {
             methodSuffix: serviceBMethodSuffix,
           },
           deleteCascade: serviceBObj.deleteCascade,
-          isList: serviceBObj.isList,
+          hasMany: serviceBObj.hasMany,
         },
       ],
       extends: [

packages/modules/link-modules/src/definitions/cart-promotion.ts

@@ -25,6 +25,7 @@ export const CartPromotion: ModuleJoinerConfig = {
       args: {
         methodSuffix: "Carts",
       },
+      hasMany: true,
     },
     {
       serviceName: Modules.PROMOTION,
@@ -35,6 +36,7 @@ export const CartPromotion: ModuleJoinerConfig = {
       args: {
         methodSuffix: "Promotions",
       },
+      hasMany: true,
     },
   ],
   extends: [

packages/modules/link-modules/src/definitions/customer-account-holder.ts

@@ -35,6 +35,7 @@ export const CustomerAccountHolder: ModuleJoinerConfig = {
       args: {
         methodSuffix: "AccountHolders",
       },
+      hasMany: true,
     },
   ],
   extends: [

packages/modules/link-modules/src/definitions/fulfillment-provider-location.ts

@@ -23,6 +23,7 @@ export const LocationFulfillmentProvider: ModuleJoinerConfig = {
       foreignKey: "stock_location_id",
       alias: "location",
       args: { methodSuffix: "StockLocations" },
+      hasMany: true,
     },
     {
       serviceName: Modules.FULFILLMENT,
@@ -31,6 +32,7 @@ export const LocationFulfillmentProvider: ModuleJoinerConfig = {
       foreignKey: "fulfillment_provider_id",
       alias: "fulfillment_provider",
       args: { methodSuffix: "FulfillmentProviders" },
+      hasMany: true,
     },
   ],
   extends: [

packages/modules/link-modules/src/definitions/fulfillment-set-location.ts

@@ -36,6 +36,7 @@ export const LocationFulfillmentSet: ModuleJoinerConfig = {
         methodSuffix: "FulfillmentSets",
       },
       deleteCascade: true,
+      hasMany: true,
     },
   ],
   extends: [

packages/modules/link-modules/src/definitions/order-claim-payment-collection.ts

@@ -38,6 +38,7 @@ export const OrderClaimPaymentCollection: ModuleJoinerConfig = {
       args: {
         methodSuffix: "PaymentCollections",
       },
+      hasMany: true,
     },
   ],
   extends: [

packages/modules/link-modules/src/definitions/order-exchange-payment-collection.ts

@@ -38,6 +38,7 @@ export const OrderExchangePaymentCollection: ModuleJoinerConfig = {
       args: {
         methodSuffix: "PaymentCollections",
       },
+      hasMany: true,
     },
   ],
   extends: [

packages/modules/link-modules/src/definitions/order-fulfillment.ts

@@ -35,6 +35,7 @@ export const OrderFulfillment: ModuleJoinerConfig = {
       args: {
         methodSuffix: "Fulfillments",
       },
+      hasMany: true,
     },
   ],
   extends: [

packages/modules/link-modules/src/definitions/order-payment-collection.ts

@@ -36,6 +36,7 @@ export const OrderPaymentCollection: ModuleJoinerConfig = {
         methodSuffix: "PaymentCollections",
       },
       deleteCascade: true,
+      hasMany: true,
     },
   ],
   extends: [

packages/modules/link-modules/src/definitions/order-promotion.ts

@@ -25,6 +25,7 @@ export const OrderPromotion: ModuleJoinerConfig = {
       args: {
         methodSuffix: "Orders",
       },
+      hasMany: true,
     },
     {
       serviceName: Modules.PROMOTION,
@@ -35,6 +36,7 @@ export const OrderPromotion: ModuleJoinerConfig = {
       args: {
         methodSuffix: "Promotions",
       },
+      hasMany: true,
     },
   ],
   extends: [

packages/modules/link-modules/src/definitions/order-return-fulfillment.ts

@@ -35,6 +35,7 @@ export const ReturnFulfillment: ModuleJoinerConfig = {
       args: {
         methodSuffix: "Fulfillments",
       },
+      hasMany: true,
     },
   ],
   extends: [

packages/modules/link-modules/src/definitions/product-sales-channel.ts

@@ -27,6 +27,7 @@ export const ProductSalesChannel: ModuleJoinerConfig = {
       args: {
         methodSuffix: "Products",
       },
+      hasMany: true,
     },
     {
       serviceName: Modules.SALES_CHANNEL,
@@ -37,6 +38,7 @@ export const ProductSalesChannel: ModuleJoinerConfig = {
       args: {
         methodSuffix: "SalesChannels",
       },
+      hasMany: true,
     },
   ],
   extends: [

packages/modules/link-modules/src/definitions/product-shipping-profile.ts

@@ -27,6 +27,7 @@ export const ProductShippingProfile: ModuleJoinerConfig = {
       args: {
         methodSuffix: "Products",
       },
+      hasMany: true,
     },
     {
       serviceName: Modules.FULFILLMENT,

packages/modules/link-modules/src/definitions/product-variant-inventory-item.ts

@@ -34,6 +34,7 @@ export const ProductVariantInventoryItem: ModuleJoinerConfig = {
       args: {
         methodSuffix: "ProductVariants",
       },
+      hasMany: true,
     },
     {
       serviceName: Modules.INVENTORY,
@@ -44,6 +45,7 @@ export const ProductVariantInventoryItem: ModuleJoinerConfig = {
       args: {
         methodSuffix: "InventoryItems",
       },
+      hasMany: true,
     },
   ],
   extends: [

packages/modules/link-modules/src/definitions/publishable-api-key-sales-channel.ts

@@ -27,6 +27,7 @@ export const PublishableApiKeySalesChannel: ModuleJoinerConfig = {
       args: {
         methodSuffix: "ApiKeys",
       },
+      hasMany: true,
     },
     {
       serviceName: Modules.SALES_CHANNEL,
@@ -37,6 +38,7 @@ export const PublishableApiKeySalesChannel: ModuleJoinerConfig = {
       args: {
         methodSuffix: "SalesChannels",
       },
+      hasMany: true,
     },
   ],
   extends: [

packages/modules/link-modules/src/definitions/region-payment-provider.ts

@@ -25,6 +25,7 @@ export const RegionPaymentProvider: ModuleJoinerConfig = {
       args: {
         methodSuffix: "Regions",
       },
+      hasMany: true,
     },
     {
       serviceName: Modules.PAYMENT,
@@ -33,6 +34,7 @@ export const RegionPaymentProvider: ModuleJoinerConfig = {
       foreignKey: "payment_provider_id",
       alias: "payment_provider",
       args: { methodSuffix: "PaymentProviders" },
+      hasMany: true,
     },
   ],
   extends: [

packages/modules/link-modules/src/definitions/sales-channel-location.ts

@@ -25,6 +25,7 @@ export const SalesChannelLocation: ModuleJoinerConfig = {
       args: {
         methodSuffix: "SalesChannels",
       },
+      hasMany: true,
     },
     {
       serviceName: Modules.STOCK_LOCATION,
@@ -35,6 +36,7 @@ export const SalesChannelLocation: ModuleJoinerConfig = {
       args: {
         methodSuffix: "StockLocations",
       },
+      hasMany: true,
     },
   ],
   extends: [