fix: custom link resolution in medusa app (#7950)

* fix custom link resolution in medusa app

* improve

* fix duplicate

packages/core/modules-sdk/src/medusa-app.ts

@@ -435,12 +435,6 @@ async function MedusaApp_({
       ...(sharedResourcesConfig?.database ?? {}),
     }
 
-    const customLinks = MedusaModule.getCustomLinks().map((link) => {
-      return typeof link === "function"
-        ? link(MedusaModule.getAllJoinerConfigs())
-        : link
-    })
-
     if (revert) {
       revertLinkModuleMigration &&
         (await revertLinkModuleMigration(
@@ -448,7 +442,7 @@ async function MedusaApp_({
             options: linkModuleOpt,
             injectedDependencies,
           },
-          customLinks
+          linkModules
         ))
     } else {
       linkModuleMigration &&
@@ -457,7 +451,7 @@ async function MedusaApp_({
             options: linkModuleOpt,
             injectedDependencies,
           },
-          customLinks
+          linkModules
         ))
     }
   }

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

@@ -2,6 +2,8 @@ import { LinkModulesExtraFields, ModuleJoinerConfig } from "@medusajs/types"
 import { isObject, pluralize, toPascalCase } from "../common"
 import { composeLinkName } from "../link"
 
+export const DefineLinkSymbol = Symbol.for("DefineLink")
+
 type InputSource = {
   serviceName: string
   field: string
@@ -116,7 +118,7 @@ export function defineLink(
     throw new Error(`Invalid linkable passed for the second argument`)
   }
 
-  const output = { serviceName: "" }
+  const output = { [DefineLinkSymbol]: true, serviceName: "" }
 
   const register = function (
     modules: ModuleJoinerConfig[]