fix: DML relation management for many to one relation ship foreign keys (#7790)

FIXES CORE-2369 cc @thetutlage Co-authored-by: Oli Juhl <59018053+olivermrbl@users.noreply.github.com>
2024-06-24 20:54:54 +02:00
parent 25210369d9
commit 34c44078e7
9 changed files with 626 additions and 235 deletions
--- a/packages/core/types/src/dml/index.ts
+++ b/packages/core/types/src/dml/index.ts
@@ -97,17 +97,36 @@ export interface EntityConstructor<Props> extends Function {
  new (): Props
 }

+/**
+ * From a IDmlEntity, infer the foreign keys name and type for belongsTo relation meaning hasOne and ManyToOne
+ */
+export type InferForeignKeys<T> = T extends IDmlEntity<infer Schema>
+  ? {
+      [K in keyof Schema as Schema[K] extends RelationshipType<any>
+        ? Schema[K]["type"] extends "belongsTo"
+          ? `${K & string}_id`
+          : K
+        : K]: Schema[K] extends RelationshipType<infer R>
+        ? Schema[K]["type"] extends "belongsTo"
+          ? string
+          : Schema[K]
+        : Schema[K]
+    }
+  : never
+
 /**
 * Helper to infer the schema type of a DmlEntity
 */
 export type Infer<T> = T extends IDmlEntity<infer Schema>
-  ? EntityConstructor<{
-      [K in keyof Schema]: Schema[K]["$dataType"] extends () => infer R
-        ? Infer<R>
-        : Schema[K]["$dataType"] extends (() => infer R) | null
-        ? Infer<R> | null
-        : Schema[K]["$dataType"]
-    }>
+  ? EntityConstructor<
+      {
+        [K in keyof Schema]: Schema[K]["$dataType"] extends () => infer R
+          ? Infer<R>
+          : Schema[K]["$dataType"] extends (() => infer R) | null
+          ? Infer<R> | null
+          : Schema[K]["$dataType"]
+      } & InferForeignKeys<T>
+    >
  : never

 /**
@@ -133,7 +152,7 @@ export type EntityCascades<Relationships> = {
 }

 /**
- * Helper to infer the instance type of a DmlEntity once converted as an Entity
+ * Helper to infer the instance type of a IDmlEntity once converted as an Entity
 */
 export type InferTypeOf<T extends IDmlEntity<any>> = InstanceType<Infer<T>>

--- a/packages/core/utils/src/common/file-system.ts
+++ b/packages/core/utils/src/common/file-system.ts
@@ -1,12 +1,12 @@
 import { dirname, join } from "path"
 import {
-  promises,
  constants,
  type Dirent,
+  type MakeDirectoryOptions,
+  promises,
  type RmOptions,
  type StatOptions,
  type WriteFileOptions,
-  type MakeDirectoryOptions,
 } from "fs"

 const { rm, stat, mkdir, access, readdir, readFile, writeFile } = promises
@@ -31,7 +31,7 @@ export class FileSystem {
   * Cleanup directory
   */
  async cleanup(options?: RmOptions) {
-    return rm(this.basePath, {
+    return await rm(this.basePath, {
      recursive: true,
      maxRetries: 10,
      force: true,
@@ -61,7 +61,7 @@ export class FileSystem {
   * Remove a file
   */
  async remove(filePath: string, options?: RmOptions) {
-    return rm(this.makePath(filePath), {
+    return await rm(this.makePath(filePath), {
      recursive: true,
      force: true,
      maxRetries: 2,
@@ -103,7 +103,7 @@ export class FileSystem {
   * Returns file contents
   */
  async contents(filePath: string) {
-    return readFile(this.makePath(filePath), "utf-8")
+    return await readFile(this.makePath(filePath), "utf-8")
  }

  /**
@@ -139,14 +139,14 @@ export class FileSystem {
  async createJson(filePath: string, contents: any, options?: JSONFileOptions) {
    if (options && typeof options === "object") {
      const { replacer, spaces, ...rest } = options
-      return this.create(
+      return await this.create(
        filePath,
        JSON.stringify(contents, replacer, spaces),
        rest
      )
    }

-    return this.create(filePath, JSON.stringify(contents), options)
+    return await this.create(filePath, JSON.stringify(contents), options)
  }

  /**
--- a/packages/core/utils/src/dml/tests/entity-builder.spec.ts
+++ b/packages/core/utils/src/dml/tests/entity-builder.spec.ts
@@ -1,12 +1,13 @@
+import { EntityConstructor } from "@medusajs/types"
 import { MetadataStorage } from "@mikro-orm/core"
 import { expectTypeOf } from "expect-type"
 import { DmlEntity } from "../entity"
-import { EntityBuilder } from "../entity-builder"
+import { model } from "../entity-builder"
 import {
  createMikrORMEntity,
+  toMikroOrmEntities,
  toMikroORMEntity,
 } from "../helpers/create-mikro-orm-entity"
-import { EntityConstructor } from "../types"

 describe("Entity builder", () => {
  beforeEach(() => {
@@ -15,7 +16,6 @@ describe("Entity builder", () => {

  describe("Entity builder | properties", () => {
    test("should identify a DML entity correctly", () => {
-      const model = new EntityBuilder()
      const user = model.define("user", {
        id: model.number(),
        username: model.text(),
@@ -30,7 +30,6 @@ describe("Entity builder", () => {
    })

    test("define an entity", () => {
-      const model = new EntityBuilder()
      const user = model.define("user", {
        id: model.number(),
        username: model.text(),
@@ -38,8 +37,7 @@ describe("Entity builder", () => {
        spend_limit: model.bigNumber(),
      })

-      const entityBuilder = createMikrORMEntity()
-      const User = entityBuilder(user)
+      const User = toMikroORMEntity(user)

      expectTypeOf(new User()).toMatchTypeOf<{
        id: number
@@ -148,7 +146,6 @@ describe("Entity builder", () => {
    })

    test("define a property with default value", () => {
-      const model = new EntityBuilder()
      const user = model.define("user", {
        id: model.number(),
        username: model.text().default("foo"),
@@ -156,8 +153,7 @@ describe("Entity builder", () => {
        spend_limit: model.bigNumber().default(500.4),
      })

-      const entityBuilder = createMikrORMEntity()
-      const User = entityBuilder(user)
+      const User = toMikroORMEntity(user)
      expectTypeOf(new User()).toMatchTypeOf<{
        id: number
        username: string
@@ -263,7 +259,6 @@ describe("Entity builder", () => {
    })

    test("mark property nullable", () => {
-      const model = new EntityBuilder()
      const user = model.define("user", {
        id: model.number(),
        username: model.text().nullable(),
@@ -398,7 +393,6 @@ describe("Entity builder", () => {
    })

    test("define an entity with enum property", () => {
-      const model = new EntityBuilder()
      const user = model.define("user", {
        id: model.number(),
        username: model.text(),
@@ -406,8 +400,7 @@ describe("Entity builder", () => {
        role: model.enum(["moderator", "admin", "guest"]),
      })

-      const entityBuilder = createMikrORMEntity()
-      const User = entityBuilder(user)
+      const User = toMikroORMEntity(user)
      expectTypeOf(new User()).toMatchTypeOf<{
        id: number
        username: string
@@ -507,7 +500,6 @@ describe("Entity builder", () => {
    })

    test("define enum property with default value", () => {
-      const model = new EntityBuilder()
      const user = model.define("user", {
        id: model.number(),
        username: model.text(),
@@ -515,8 +507,7 @@ describe("Entity builder", () => {
        role: model.enum(["moderator", "admin", "guest"]).default("guest"),
      })

-      const entityBuilder = createMikrORMEntity()
-      const User = entityBuilder(user)
+      const User = toMikroORMEntity(user)
      expectTypeOf(new User()).toMatchTypeOf<{
        id: number
        username: string
@@ -616,7 +607,6 @@ describe("Entity builder", () => {
    })

    test("mark enum property nullable", () => {
-      const model = new EntityBuilder()
      const user = model.define("user", {
        id: model.number(),
        username: model.text(),
@@ -624,8 +614,7 @@ describe("Entity builder", () => {
        role: model.enum(["moderator", "admin", "guest"]).nullable(),
      })

-      const entityBuilder = createMikrORMEntity()
-      const User = entityBuilder(user)
+      const User = toMikroORMEntity(user)
      expectTypeOf(new User()).toMatchTypeOf<{
        id: number
        username: string
@@ -730,7 +719,6 @@ describe("Entity builder", () => {
    })

    test("disallow defining created_at and updated_at timestamps", () => {
-      const model = new EntityBuilder()
      expect(() =>
        model.define("user", {
          id: model.number(),
@@ -745,7 +733,6 @@ describe("Entity builder", () => {
    })

    test("disallow defining deleted_at timestamp", () => {
-      const model = new EntityBuilder()
      expect(() =>
        model.define("user", {
          id: model.number(),
@@ -759,15 +746,13 @@ describe("Entity builder", () => {
    })

    test("define pg schema name in the entity name", () => {
-      const model = new EntityBuilder()
      const user = model.define("public.user", {
        id: model.number(),
        username: model.text(),
        email: model.text(),
      })

-      const entityBuilder = createMikrORMEntity()
-      const User = entityBuilder(user)
+      const User = toMikroORMEntity(user)
      expectTypeOf(new User()).toMatchTypeOf<{
        id: number
        username: string
@@ -857,15 +842,13 @@ describe("Entity builder", () => {

  describe("Entity builder | id", () => {
    test("define an entity with id property", () => {
-      const model = new EntityBuilder()
      const user = model.define("user", {
        id: model.id(),
        username: model.text(),
        email: model.text(),
      })

-      const entityBuilder = createMikrORMEntity()
-      const User = entityBuilder(user)
+      const User = toMikroORMEntity(user)
      expectTypeOf(new User()).toMatchTypeOf<{
        id: string
        username: string
@@ -956,15 +939,13 @@ describe("Entity builder", () => {
    })

    test("mark id as non-primary", () => {
-      const model = new EntityBuilder()
      const user = model.define("user", {
        id: model.id({ primaryKey: false }),
        username: model.text(),
        email: model.text(),
      })

-      const entityBuilder = createMikrORMEntity()
-      const User = entityBuilder(user)
+      const User = toMikroORMEntity(user)
      expectTypeOf(new User()).toMatchTypeOf<{
        id: string
        username: string
@@ -1061,15 +1042,13 @@ describe("Entity builder", () => {
    })

    test("define prefix for the id", () => {
-      const model = new EntityBuilder()
      const user = model.define("user", {
        id: model.id({ primaryKey: false, prefix: "us" }),
        username: model.text(),
        email: model.text(),
      })

-      const entityBuilder = createMikrORMEntity()
-      const User = entityBuilder(user)
+      const User = toMikroORMEntity(user)
      expectTypeOf(new User()).toMatchTypeOf<{
        id: string
        username: string
@@ -1168,7 +1147,6 @@ describe("Entity builder", () => {

  describe("Entity builder | primaryKey", () => {
    test("should create both id fields and primaryKey fields", () => {
-      const model = new EntityBuilder()
      const user = model.define("user", {
        id: model.id({ primaryKey: false }),
        email: model.text().primaryKey(),
@@ -1271,15 +1249,13 @@ describe("Entity builder", () => {

  describe("Entity builder | indexes", () => {
    test("define index on a field", () => {
-      const model = new EntityBuilder()
      const user = model.define("user", {
        id: model.number().index(),
        username: model.text(),
        email: model.text().unique(),
      })

-      const entityBuilder = createMikrORMEntity()
-      const User = entityBuilder(user)
+      const User = toMikroORMEntity(user)
      expectTypeOf(new User()).toMatchTypeOf<{
        id: number
        username: string
@@ -1377,15 +1353,13 @@ describe("Entity builder", () => {
    })

    test("define index when entity is using an explicit pg Schema", () => {
-      const model = new EntityBuilder()
      const user = model.define("platform.user", {
        id: model.number().index(),
        username: model.text(),
        email: model.text().unique(),
      })

-      const entityBuilder = createMikrORMEntity()
-      const User = entityBuilder(user)
+      const User = toMikroORMEntity(user)
      expectTypeOf(new User()).toMatchTypeOf<{
        id: number
        username: string
@@ -1486,7 +1460,6 @@ describe("Entity builder", () => {

  describe("Entity builder | hasOne", () => {
    test("define hasOne relationship", () => {
-      const model = new EntityBuilder()
      const email = model.define("email", {
        email: model.text(),
        isVerified: model.boolean(),
@@ -1498,8 +1471,7 @@ describe("Entity builder", () => {
        email: model.hasOne(() => email),
      })

-      const entityBuilder = createMikrORMEntity()
-      const User = entityBuilder(user)
+      const User = toMikroORMEntity(user)
      expectTypeOf(new User()).toMatchTypeOf<{
        id: number
        username: string
@@ -1576,7 +1548,6 @@ describe("Entity builder", () => {
    })

    test("mark hasOne relationship as nullable", () => {
-      const model = new EntityBuilder()
      const email = model.define("email", {
        email: model.text(),
        isVerified: model.boolean(),
@@ -1588,8 +1559,7 @@ describe("Entity builder", () => {
        emails: model.hasOne(() => email).nullable(),
      })

-      const entityBuilder = createMikrORMEntity()
-      const User = entityBuilder(user)
+      const User = toMikroORMEntity(user)

      expectTypeOf(new User()).toMatchTypeOf<{
        id: number
@@ -1667,7 +1637,6 @@ describe("Entity builder", () => {
    })

    test("define custom mappedBy key for relationship", () => {
-      const model = new EntityBuilder()
      const email = model.define("email", {
        email: model.text(),
        isVerified: model.boolean(),
@@ -1679,8 +1648,7 @@ describe("Entity builder", () => {
        email: model.hasOne(() => email, { mappedBy: "owner" }),
      })

-      const entityBuilder = createMikrORMEntity()
-      const User = entityBuilder(user)
+      const User = toMikroORMEntity(user)
      expectTypeOf(new User()).toMatchTypeOf<{
        id: number
        username: string
@@ -1752,7 +1720,6 @@ describe("Entity builder", () => {
    })

    test("define delete cascades for the entity", () => {
-      const model = new EntityBuilder()
      const email = model.define("email", {
        email: model.text(),
        isVerified: model.boolean(),
@@ -1768,8 +1735,7 @@ describe("Entity builder", () => {
          delete: ["email"],
        })

-      const entityBuilder = createMikrORMEntity()
-      const User = entityBuilder(user)
+      const User = toMikroORMEntity(user)
      expectTypeOf(new User()).toMatchTypeOf<{
        id: number
        username: string
@@ -1840,7 +1806,7 @@ describe("Entity builder", () => {
        },
      })

-      const Email = entityBuilder(email)
+      const Email = toMikroORMEntity(email)
      const emailMetaData = MetadataStorage.getMetadataFromDecorator(Email)
      expect(emailMetaData.className).toEqual("Email")
      expect(emailMetaData.path).toEqual("Email")
@@ -1899,7 +1865,6 @@ describe("Entity builder", () => {
    })

    test("define delete cascades with belongsTo on the other end", () => {
-      const model = new EntityBuilder()
      const email = model.define("email", {
        email: model.text(),
        isVerified: model.boolean(),
@@ -1916,8 +1881,7 @@ describe("Entity builder", () => {
          delete: ["email"],
        })

-      const entityBuilder = createMikrORMEntity()
-      const User = entityBuilder(user)
+      const User = toMikroORMEntity(user)
      expectTypeOf(new User()).toMatchTypeOf<{
        id: number
        username: string
@@ -1995,7 +1959,7 @@ describe("Entity builder", () => {
        },
      })

-      const Email = entityBuilder(email)
+      const Email = toMikroORMEntity(email)
      const emailMetaData = MetadataStorage.getMetadataFromDecorator(Email)
      expect(emailMetaData.className).toEqual("Email")
      expect(emailMetaData.path).toEqual("Email")
@@ -2027,6 +1991,15 @@ describe("Entity builder", () => {
          owner: true,
          reference: "1:1",
        },
+        user_id: {
+          columnType: "text",
+          getter: false,
+          name: "user_id",
+          nullable: false,
+          reference: "scalar",
+          setter: false,
+          type: "string",
+        },
        created_at: {
          reference: "scalar",
          type: "date",
@@ -2065,7 +2038,6 @@ describe("Entity builder", () => {

  describe("Entity builder | hasMany", () => {
    test("define hasMany relationship", () => {
-      const model = new EntityBuilder()
      const email = model.define("email", {
        email: model.text(),
        isVerified: model.boolean(),
@@ -2077,8 +2049,7 @@ describe("Entity builder", () => {
        emails: model.hasMany(() => email),
      })

-      const entityBuilder = createMikrORMEntity()
-      const User = entityBuilder(user)
+      const User = toMikroORMEntity(user)
      expectTypeOf(new User()).toMatchTypeOf<{
        id: number
        username: string
@@ -2150,7 +2121,6 @@ describe("Entity builder", () => {
    })

    test("define custom mappedBy property name for hasMany relationship", () => {
-      const model = new EntityBuilder()
      const email = model.define("email", {
        email: model.text(),
        isVerified: model.boolean(),
@@ -2164,8 +2134,7 @@ describe("Entity builder", () => {
        }),
      })

-      const entityBuilder = createMikrORMEntity()
-      const User = entityBuilder(user)
+      const User = toMikroORMEntity(user)

      expectTypeOf(new User()).toMatchTypeOf<{
        id: number
@@ -2238,7 +2207,6 @@ describe("Entity builder", () => {
    })

    test("define delete cascades for the entity", () => {
-      const model = new EntityBuilder()
      const email = model.define("email", {
        email: model.text(),
        isVerified: model.boolean(),
@@ -2254,8 +2222,7 @@ describe("Entity builder", () => {
          delete: ["emails"],
        })

-      const entityBuilder = createMikrORMEntity()
-      const User = entityBuilder(user)
+      const User = toMikroORMEntity(user)
      expectTypeOf(new User()).toMatchTypeOf<{
        id: number
        username: string
@@ -2328,7 +2295,6 @@ describe("Entity builder", () => {
    })

    test("define delete cascades with belongsTo on the other end", () => {
-      const model = new EntityBuilder()
      const email = model.define("email", {
        email: model.text(),
        isVerified: model.boolean(),
@@ -2345,9 +2311,8 @@ describe("Entity builder", () => {
          delete: ["emails"],
        })

-      const entityBuilder = createMikrORMEntity()
-      const User = entityBuilder(user)
-      const Email = entityBuilder(email)
+      const User = toMikroORMEntity(user)
+      const Email = toMikroORMEntity(email)
      expectTypeOf(new User()).toMatchTypeOf<{
        id: number
        username: string
@@ -2441,10 +2406,11 @@ describe("Entity builder", () => {
          setter: false,
        },
        user: {
-          reference: "m:1",
-          name: "user",
          entity: "User",
+          name: "user",
+          nullable: false,
          persist: false,
+          reference: "m:1",
        },
        user_id: {
          columnType: "text",
@@ -2453,8 +2419,8 @@ describe("Entity builder", () => {
          mapToPk: true,
          name: "user_id",
          nullable: false,
-          reference: "m:1",
          onDelete: "cascade",
+          reference: "m:1",
        },
        created_at: {
          reference: "scalar",
@@ -2494,8 +2460,6 @@ describe("Entity builder", () => {

  describe("Entity builder | belongsTo", () => {
    test("define belongsTo relationship with hasOne", () => {
-      const model = new EntityBuilder()
-
      const email = model.define("email", {
        email: model.text(),
        isVerified: model.boolean(),
@@ -2508,9 +2472,7 @@ describe("Entity builder", () => {
        email: model.hasOne(() => email),
      })

-      const entityBuilder = createMikrORMEntity()
-      const User = entityBuilder(user)
-      const Email = entityBuilder(email)
+      const [User, Email] = [user, email].map(toMikroORMEntity)

      expectTypeOf(new User()).toMatchTypeOf<{
        id: number
@@ -2630,12 +2592,21 @@ describe("Entity builder", () => {
          setter: false,
        },
        user: {
-          reference: "1:1",
          name: "user",
+          reference: "1:1",
          entity: "User",
          nullable: false,
-          owner: true,
          mappedBy: "email",
+          owner: true,
+        },
+        user_id: {
+          reference: "scalar",
+          type: "string",
+          columnType: "text",
+          nullable: false,
+          name: "user_id",
+          getter: false,
+          setter: false,
        },
        created_at: {
          reference: "scalar",
@@ -2673,8 +2644,6 @@ describe("Entity builder", () => {
    })

    test("mark belongsTo with hasOne as nullable", () => {
-      const model = new EntityBuilder()
-
      const email = model.define("email", {
        email: model.text(),
        isVerified: model.boolean(),
@@ -2687,9 +2656,8 @@ describe("Entity builder", () => {
        email: model.hasOne(() => email),
      })

-      const entityBuilder = createMikrORMEntity()
-      const User = entityBuilder(user)
-      const Email = entityBuilder(email)
+      const User = toMikroORMEntity(user)
+      const Email = toMikroORMEntity(email)

      expectTypeOf(new User()).toMatchTypeOf<{
        id: number
@@ -2803,12 +2771,21 @@ describe("Entity builder", () => {
          setter: false,
        },
        user: {
-          reference: "1:1",
          name: "user",
+          reference: "1:1",
          entity: "User",
          nullable: true,
-          owner: true,
          mappedBy: "email",
+          owner: true,
+        },
+        user_id: {
+          reference: "scalar",
+          type: "string",
+          columnType: "text",
+          nullable: true,
+          name: "user_id",
+          getter: false,
+          setter: false,
        },
        created_at: {
          reference: "scalar",
@@ -2846,8 +2823,6 @@ describe("Entity builder", () => {
    })

    test("define belongsTo relationship with hasMany", () => {
-      const model = new EntityBuilder()
-
      const email = model.define("email", {
        email: model.text(),
        isVerified: model.boolean(),
@@ -2860,9 +2835,8 @@ describe("Entity builder", () => {
        emails: model.hasMany(() => email),
      })

-      const entityBuilder = createMikrORMEntity()
-      const User = entityBuilder(user)
-      const Email = entityBuilder(email)
+      const User = toMikroORMEntity(user)
+      const Email = toMikroORMEntity(email)

      expectTypeOf(new User()).toMatchTypeOf<{
        id: number
@@ -2976,19 +2950,20 @@ describe("Entity builder", () => {
          setter: false,
        },
        user: {
-          reference: "m:1",
          name: "user",
+          reference: "m:1",
          entity: "User",
          persist: false,
+          nullable: false,
        },
        user_id: {
-          columnType: "text",
-          entity: "User",
-          fieldName: "user_id",
-          mapToPk: true,
          name: "user_id",
-          nullable: false,
          reference: "m:1",
+          entity: "User",
+          columnType: "text",
+          mapToPk: true,
+          fieldName: "user_id",
+          nullable: false,
        },
        created_at: {
          reference: "scalar",
@@ -3026,8 +3001,6 @@ describe("Entity builder", () => {
    })

    test("define belongsTo with hasMany as nullable", () => {
-      const model = new EntityBuilder()
-
      const email = model.define("email", {
        email: model.text(),
        isVerified: model.boolean(),
@@ -3040,9 +3013,8 @@ describe("Entity builder", () => {
        emails: model.hasMany(() => email),
      })

-      const entityBuilder = createMikrORMEntity()
-      const User = entityBuilder(user)
-      const Email = entityBuilder(email)
+      const User = toMikroORMEntity(user)
+      const Email = toMikroORMEntity(email)

      expectTypeOf(new User()).toMatchTypeOf<{
        id: number
@@ -3156,19 +3128,20 @@ describe("Entity builder", () => {
          setter: false,
        },
        user: {
-          reference: "m:1",
          name: "user",
+          reference: "m:1",
          entity: "User",
          persist: false,
+          nullable: true,
        },
        user_id: {
-          columnType: "text",
-          entity: "User",
-          fieldName: "user_id",
-          mapToPk: true,
          name: "user_id",
-          nullable: true,
          reference: "m:1",
+          entity: "User",
+          columnType: "text",
+          mapToPk: true,
+          fieldName: "user_id",
+          nullable: true,
        },
        created_at: {
          reference: "scalar",
@@ -3206,8 +3179,6 @@ describe("Entity builder", () => {
    })

    test("throw error when other side relationship is missing", () => {
-      const model = new EntityBuilder()
-
      const email = model.define("email", {
        email: model.text(),
        isVerified: model.boolean(),
@@ -3219,15 +3190,12 @@ describe("Entity builder", () => {
        username: model.text(),
      })

-      const entityBuilder = createMikrORMEntity()
-      expect(() => entityBuilder(email)).toThrow(
+      expect(() => toMikroORMEntity(email)).toThrow(
        'Missing property "email" on "User" entity. Make sure to define it as a relationship'
      )
    })

    test("throw error when other side relationship is invalid", () => {
-      const model = new EntityBuilder()
-
      const email = model.define("email", {
        email: model.text(),
        isVerified: model.boolean(),
@@ -3240,15 +3208,12 @@ describe("Entity builder", () => {
        email: model.belongsTo(() => email),
      })

-      const entityBuilder = createMikrORMEntity()
-      expect(() => entityBuilder(email)).toThrow(
+      expect(() => toMikroORMEntity(email)).toThrow(
        'Invalid relationship reference for "email" on "User" entity. Make sure to define a hasOne or hasMany relationship'
      )
    })

    test("throw error when cascading a parent from a child", () => {
-      const model = new EntityBuilder()
-
      const user = model.define("user", {
        id: model.number(),
        username: model.text(),
@@ -3272,8 +3237,6 @@ describe("Entity builder", () => {
    })

    test("define relationships when entity names has pg schema name", () => {
-      const model = new EntityBuilder()
-
      const email = model.define("platform.email", {
        email: model.text(),
        isVerified: model.boolean(),
@@ -3286,9 +3249,8 @@ describe("Entity builder", () => {
        email: model.hasOne(() => email),
      })

-      const entityBuilder = createMikrORMEntity()
-      const User = entityBuilder(user)
-      const Email = entityBuilder(email)
+      const User = toMikroORMEntity(user)
+      const Email = toMikroORMEntity(email)

      expectTypeOf(new User()).toMatchTypeOf<{
        id: number
@@ -3410,12 +3372,21 @@ describe("Entity builder", () => {
          setter: false,
        },
        user: {
-          reference: "1:1",
          name: "user",
+          reference: "1:1",
          entity: "User",
          nullable: false,
-          owner: true,
          mappedBy: "email",
+          owner: true,
+        },
+        user_id: {
+          reference: "scalar",
+          type: "string",
+          columnType: "text",
+          nullable: false,
+          name: "user_id",
+          getter: false,
+          setter: false,
        },
        created_at: {
          reference: "scalar",
@@ -3453,8 +3424,6 @@ describe("Entity builder", () => {
    })

    test("define relationships between cross pg schemas entities", () => {
-      const model = new EntityBuilder()
-
      const email = model.define("platform.email", {
        email: model.text(),
        isVerified: model.boolean(),
@@ -3467,9 +3436,8 @@ describe("Entity builder", () => {
        email: model.hasOne(() => email),
      })

-      const entityBuilder = createMikrORMEntity()
-      const User = entityBuilder(user)
-      const Email = entityBuilder(email)
+      const User = toMikroORMEntity(user)
+      const Email = toMikroORMEntity(email)

      expectTypeOf(new User()).toMatchTypeOf<{
        id: number
@@ -3591,12 +3559,21 @@ describe("Entity builder", () => {
          setter: false,
        },
        user: {
-          reference: "1:1",
          name: "user",
+          reference: "1:1",
          entity: "User",
          nullable: false,
-          owner: true,
          mappedBy: "email",
+          owner: true,
+        },
+        user_id: {
+          reference: "scalar",
+          type: "string",
+          columnType: "text",
+          nullable: false,
+          name: "user_id",
+          getter: false,
+          setter: false,
        },
        created_at: {
          reference: "scalar",
@@ -3636,7 +3613,6 @@ describe("Entity builder", () => {

  describe("Entity builder | manyToMany", () => {
    test("define manyToMany relationship", () => {
-      const model = new EntityBuilder()
      const team = model.define("team", {
        id: model.number(),
        name: model.text(),
@@ -3649,9 +3625,8 @@ describe("Entity builder", () => {
        teams: model.manyToMany(() => team),
      })

-      const entityBuilder = createMikrORMEntity()
-      const User = entityBuilder(user)
-      const Team = entityBuilder(team)
+      const User = toMikroORMEntity(user)
+      const Team = toMikroORMEntity(team)

      expectTypeOf(new User()).toMatchTypeOf<{
        id: number
@@ -3805,7 +3780,6 @@ describe("Entity builder", () => {
    })

    test("define mappedBy on one side", () => {
-      const model = new EntityBuilder()
      const team = model.define("team", {
        id: model.number(),
        name: model.text(),
@@ -3818,9 +3792,8 @@ describe("Entity builder", () => {
        teams: model.manyToMany(() => team, { mappedBy: "users" }),
      })

-      const entityBuilder = createMikrORMEntity()
-      const User = entityBuilder(user)
-      const Team = entityBuilder(team)
+      const User = toMikroORMEntity(user)
+      const Team = toMikroORMEntity(team)

      expectTypeOf(new User()).toMatchTypeOf<{
        id: number
@@ -3975,7 +3948,6 @@ describe("Entity builder", () => {
    })

    test("throw error when unable to locate relationship via mappedBy", () => {
-      const model = new EntityBuilder()
      const team = model.define("team", {
        id: model.number(),
        name: model.text(),
@@ -3987,14 +3959,12 @@ describe("Entity builder", () => {
        teams: model.manyToMany(() => team, { mappedBy: "users" }),
      })

-      const entityBuilder = createMikrORMEntity()
-      expect(() => entityBuilder(user)).toThrow(
+      expect(() => toMikroORMEntity(user)).toThrow(
        'Missing property "users" on "Team" entity. Make sure to define it as a relationship'
      )
    })

    test("throw error when mappedBy relationship is not a manyToMany", () => {
-      const model = new EntityBuilder()
      const team = model.define("team", {
        id: model.number(),
        name: model.text(),
@@ -4007,14 +3977,12 @@ describe("Entity builder", () => {
        teams: model.manyToMany(() => team, { mappedBy: "users" }),
      })

-      const entityBuilder = createMikrORMEntity()
-      expect(() => entityBuilder(user)).toThrow(
+      expect(() => toMikroORMEntity(user)).toThrow(
        'Invalid relationship reference for "users" on "Team" entity. Make sure to define a manyToMany relationship'
      )
    })

    test("define mappedBy on both sides", () => {
-      const model = new EntityBuilder()
      const team = model.define("team", {
        id: model.number(),
        name: model.text(),
@@ -4027,9 +3995,7 @@ describe("Entity builder", () => {
        teams: model.manyToMany(() => team, { mappedBy: "users" }),
      })

-      const entityBuilder = createMikrORMEntity()
-      const User = entityBuilder(user)
-      const Team = entityBuilder(team)
+      const [User, Team] = toMikroOrmEntities([user, team, {}])

      expectTypeOf(new User()).toMatchTypeOf<{
        id: number
@@ -4189,7 +4155,6 @@ describe("Entity builder", () => {
    })

    test("define mappedBy on both sides and reverse order of registering entities", () => {
-      const model = new EntityBuilder()
      const team = model.define("team", {
        id: model.number(),
        name: model.text(),
@@ -4364,7 +4329,6 @@ describe("Entity builder", () => {
    })

    test("define multiple many to many relationships to the same entity", () => {
-      const model = new EntityBuilder()
      const team = model.define("team", {
        id: model.number(),
        name: model.text(),
@@ -4571,7 +4535,6 @@ describe("Entity builder", () => {
    })

    test("define manyToMany relationship when entity names has pg schema name", () => {
-      const model = new EntityBuilder()
      const team = model.define("platform.team", {
        id: model.number(),
        name: model.text(),
@@ -4584,9 +4547,8 @@ describe("Entity builder", () => {
        teams: model.manyToMany(() => team),
      })

-      const entityBuilder = createMikrORMEntity()
-      const User = entityBuilder(user)
-      const Team = entityBuilder(team)
+      const User = toMikroORMEntity(user)
+      const Team = toMikroORMEntity(team)

      expectTypeOf(new User()).toMatchTypeOf<{
        id: number
@@ -4742,7 +4704,6 @@ describe("Entity builder", () => {
    })

    test("define custom pivot table name", () => {
-      const model = new EntityBuilder()
      const team = model.define("team", {
        id: model.number(),
        name: model.text(),
@@ -4757,9 +4718,8 @@ describe("Entity builder", () => {
        teams: model.manyToMany(() => team, { pivotTable: "users_teams" }),
      })

-      const entityBuilder = createMikrORMEntity()
-      const User = entityBuilder(user)
-      const Team = entityBuilder(team)
+      const User = toMikroORMEntity(user)
+      const Team = toMikroORMEntity(team)

      expectTypeOf(new User()).toMatchTypeOf<{
        id: number
@@ -4913,7 +4873,6 @@ describe("Entity builder", () => {
    })

    test("define custom pivot entity", () => {
-      const model = new EntityBuilder()
      const team = model.define("team", {
        id: model.number(),
        name: model.text(),
@@ -4934,10 +4893,7 @@ describe("Entity builder", () => {
        teams: model.manyToMany(() => team, { pivotEntity: () => squad }),
      })

-      const entityBuilder = createMikrORMEntity()
-      const User = entityBuilder(user)
-      const Team = entityBuilder(team)
-      const Squad = entityBuilder(squad)
+      const [User, Team, Squad] = toMikroOrmEntities([user, team, squad])

      expectTypeOf(new User()).toMatchTypeOf<{
        id: number
@@ -4973,74 +4929,78 @@ describe("Entity builder", () => {
      expect(squadMetaData.properties).toEqual({
        id: {
          reference: "scalar",
-          type: "number",
          columnType: "integer",
-          name: "id",
+          type: "number",
          nullable: false,
+          name: "id",
          getter: false,
          setter: false,
        },
-        team: {
-          entity: "Team",
-          name: "team",
-          persist: false,
+        user_id: {
+          name: "user_id",
          reference: "m:1",
-        },
-        team_id: {
+          entity: "User",
          columnType: "text",
-          entity: "Team",
-          fieldName: "team_id",
          mapToPk: true,
-          name: "team_id",
+          fieldName: "user_id",
          nullable: false,
-          onDelete: undefined,
-          reference: "m:1",
        },
        user: {
-          entity: "User",
-          name: "user",
+          reference: "scalar",
+          type: "User",
          persist: false,
-          reference: "m:1",
-        },
-        user_id: {
-          columnType: "text",
-          entity: "User",
-          fieldName: "user_id",
-          mapToPk: true,
-          name: "user_id",
          nullable: false,
-          onDelete: undefined,
+          name: "user",
+          getter: false,
+          setter: false,
+        },
+        team_id: {
+          name: "team_id",
          reference: "m:1",
+          entity: "Team",
+          columnType: "text",
+          mapToPk: true,
+          fieldName: "team_id",
+          nullable: false,
+        },
+        team: {
+          reference: "scalar",
+          type: "Team",
+          persist: false,
+          nullable: false,
+          name: "team",
+          getter: false,
+          setter: false,
        },
        created_at: {
          reference: "scalar",
-          type: "date",
          columnType: "timestamptz",
-          name: "created_at",
-          defaultRaw: "now()",
-          onCreate: expect.any(Function),
+          type: "date",
          nullable: false,
+          onCreate: expect.any(Function),
+          defaultRaw: "now()",
+          name: "created_at",
          getter: false,
          setter: false,
        },
        updated_at: {
          reference: "scalar",
-          type: "date",
          columnType: "timestamptz",
-          name: "updated_at",
-          defaultRaw: "now()",
+          type: "date",
+          nullable: false,
          onCreate: expect.any(Function),
          onUpdate: expect.any(Function),
-          nullable: false,
+          defaultRaw: "now()",
+          name: "updated_at",
          getter: false,
          setter: false,
        },
        deleted_at: {
          reference: "scalar",
-          type: "date",
          columnType: "timestamptz",
-          name: "deleted_at",
+          type: "date",
          nullable: true,
+          name: "deleted_at",
          getter: false,
          setter: false,
        },
--- a/packages/core/utils/src/dml/helpers/create-mikro-orm-entity.ts
+++ b/packages/core/utils/src/dml/helpers/create-mikro-orm-entity.ts
@@ -154,6 +154,7 @@ export function createMikrORMEntity() {
   * - [user.teams]: true // the teams relationship on user is an owner
   * - [team.users] // cannot be an owner
   */
+  // TODO: if we use the util toMikroOrmEntities then a new builder will be used each time, lets think about this. Currently if means that with many to many we need to use the same builder
  const MANY_TO_MANY_TRACKED_REALTIONS: Record<string, boolean> = {}

  /**
@@ -390,6 +391,23 @@ export function createMikrORMEntity() {
      )
    }

+    function applyForeignKeyAssignationHooks(foreignKeyName: string) {
+      const hookName = `assignRelationFromForeignKeyValue${foreignKeyName}`
+      /**
+       * Hook to handle foreign key assignation
+       */
+      MikroORMEntity.prototype[hookName] = function () {
+        this[relationship.name] ??= this[foreignKeyName]
+        this[foreignKeyName] ??= this[relationship.name]?.id
+      }
+
+      /**
+       * Execute hook via lifecycle decorators
+       */
+      BeforeCreate()(MikroORMEntity.prototype, hookName)
+      OnInit()(MikroORMEntity.prototype, hookName)
+    }
+
    /**
     * Otherside is a has many. Hence we should defined a ManyToOne
     */
@@ -397,6 +415,8 @@ export function createMikrORMEntity() {
      otherSideRelation instanceof HasMany ||
      otherSideRelation instanceof DmlManyToMany
    ) {
+      const foreignKeyName = camelToSnakeCase(`${relationship.name}Id`)
+
      ManyToOne({
        entity: relatedModelName,
        columnType: "text",
@@ -406,10 +426,22 @@ export function createMikrORMEntity() {
        onDelete: shouldCascade ? "cascade" : undefined,
      })(MikroORMEntity.prototype, camelToSnakeCase(`${relationship.name}Id`))

-      ManyToOne({
-        entity: relatedModelName,
-        persist: false,
-      })(MikroORMEntity.prototype, relationship.name)
+      if (otherSideRelation instanceof DmlManyToMany) {
+        Property({
+          type: relatedModelName,
+          persist: false,
+          nullable: relationship.nullable,
+        })(MikroORMEntity.prototype, relationship.name)
+      } else {
+        // HasMany case
+        ManyToOne({
+          entity: relatedModelName,
+          persist: false,
+          nullable: relationship.nullable,
+        })(MikroORMEntity.prototype, relationship.name)
+      }
+
+      applyForeignKeyAssignationHooks(foreignKeyName)
      return
    }

@@ -417,6 +449,8 @@ export function createMikrORMEntity() {
     * Otherside is a has one. Hence we should defined a OneToOne
     */
    if (otherSideRelation instanceof HasOne) {
+      const foreignKeyName = camelToSnakeCase(`${relationship.name}Id`)
+
      OneToOne({
        entity: relatedModelName,
        nullable: relationship.nullable,
@@ -424,6 +458,23 @@ export function createMikrORMEntity() {
        owner: true,
        onDelete: shouldCascade ? "cascade" : undefined,
      })(MikroORMEntity.prototype, relationship.name)
+
+      if (relationship.nullable) {
+        Object.defineProperty(MikroORMEntity.prototype, foreignKeyName, {
+          value: null,
+          configurable: true,
+          enumerable: true,
+          writable: true,
+        })
+      }
+
+      Property({
+        type: "string",
+        columnType: "text",
+        nullable: relationship.nullable,
+      })(MikroORMEntity.prototype, foreignKeyName)
+
+      applyForeignKeyAssignationHooks(foreignKeyName)
      return
    }

@@ -681,12 +732,18 @@ export function createMikrORMEntity() {
 * return the input idempotently
 * @param entity
 */
-export const toMikroORMEntity = (entity: any) => {
+export const toMikroORMEntity = <T>(
+  entity: T
+): T extends DmlEntity<infer Schema> ? EntityConstructor<Schema> : T => {
+  let mikroOrmEntity: T | EntityConstructor<any> = entity
+
  if (DmlEntity.isDmlEntity(entity)) {
-    return createMikrORMEntity()(entity)
+    mikroOrmEntity = createMikrORMEntity()(entity)
  }

-  return entity
+  return mikroOrmEntity as T extends DmlEntity<infer Schema>
+    ? EntityConstructor<Schema>
+    : T
 }

 /**
@@ -694,6 +751,16 @@ export const toMikroORMEntity = (entity: any) => {
 * This action is idempotent if non of the entities are DmlEntity
 * @param entities
 */
-export const toMikroOrmEntities = function (entities: any[]) {
-  return entities.map(toMikroORMEntity)
+export const toMikroOrmEntities = function <T extends any[]>(entities: T) {
+  const entityBuilder = createMikrORMEntity()
+
+  return entities.map((entity) => {
+    if (DmlEntity.isDmlEntity(entity)) {
+      return entityBuilder(entity)
+    }
+
+    return entity
+  }) as {
+    [K in keyof T]: T[K] extends DmlEntity<any> ? EntityConstructor<T[K]> : T[K]
+  }
 }
--- a/packages/core/utils/src/dml/integration-tests/many-to-many.spec.ts
+++ b/packages/core/utils/src/dml/integration-tests/many-to-many.spec.ts
@@ -0,0 +1,193 @@
+import { MetadataStorage, MikroORM } from "@mikro-orm/core"
+import { model } from "../entity-builder"
+import { toMikroOrmEntities } from "../helpers/create-mikro-orm-entity"
+import { createDatabase, dropDatabase } from "pg-god"
+import { mikroOrmSerializer, TSMigrationGenerator } from "../../dal"
+import { FileSystem } from "../../common"
+import { join } from "path"
+import { EntityConstructor } from "@medusajs/types"
+
+const DB_HOST = process.env.DB_HOST
+const DB_USERNAME = process.env.DB_USERNAME
+const DB_PASSWORD = process.env.DB_PASSWORD
+
+const pgGodCredentials = {
+  user: DB_USERNAME,
+  password: DB_PASSWORD,
+  host: DB_HOST,
+}
+
+const fileSystem = new FileSystem(join(__dirname, "../../migrations"))
+
+describe("manyToMany - manyToMany", () => {
+  const dbName = "EntityBuilder-ManyToMany"
+
+  let orm!: MikroORM
+
+  let Team: EntityConstructor<any>,
+    User: EntityConstructor<any>,
+    Squad: EntityConstructor<any>
+
+  afterAll(() => {
+    fileSystem.cleanup()
+  })
+
+  beforeEach(async () => {
+    MetadataStorage.clear()
+
+    const team = model.define("team", {
+      id: model.id(),
+      name: model.text(),
+      users: model.manyToMany(() => user, {
+        pivotEntity: () => squad,
+        mappedBy: "squads",
+      }),
+    })
+
+    const squad = model.define("teamUsers", {
+      id: model.id(),
+      user: model.belongsTo(() => user, { mappedBy: "squads" }),
+      squad: model.belongsTo(() => team, { mappedBy: "users" }),
+    })
+
+    const user = model.define("user", {
+      id: model.id(),
+      username: model.text(),
+      squads: model.manyToMany(() => team, {
+        pivotEntity: () => squad,
+        mappedBy: "users",
+      }),
+    })
+
+    ;[User, Squad, Team] = toMikroOrmEntities([user, squad, team])
+
+    await createDatabase({ databaseName: dbName }, pgGodCredentials)
+
+    orm = await MikroORM.init({
+      entities: [Team, User, Squad],
+      tsNode: true,
+      dbName,
+      debug: true,
+      type: "postgresql",
+      migrations: {
+        generator: TSMigrationGenerator,
+      },
+    })
+
+    const migrator = orm.getMigrator()
+    await migrator.createMigration()
+    await migrator.up()
+  })
+
+  afterEach(async () => {
+    await orm.close()
+
+    await dropDatabase(
+      { databaseName: dbName, errorIfNonExist: false },
+      pgGodCredentials
+    )
+  })
+
+  it(`should handle the relation properly`, async () => {
+    let manager = orm.em.fork()
+
+    const user1 = manager.create(User, {
+      username: "User 1",
+    })
+    const user2 = manager.create(User, {
+      username: "User 2",
+    })
+
+    await manager.persistAndFlush([user1, user2])
+    manager = orm.em.fork()
+
+    const team1 = manager.create(Team, {
+      name: "Team 1",
+    })
+    const team2 = manager.create(Team, {
+      name: "Team 2",
+    })
+
+    await manager.persistAndFlush([team1, team2])
+    manager = orm.em.fork()
+
+    const squad1 = manager.create(Squad, {
+      user_id: user1.id,
+      squad_id: team1.id,
+    })
+    const squad2 = manager.create(Squad, {
+      user_id: user2.id,
+      squad_id: team1.id,
+    })
+
+    await manager.persistAndFlush([squad1, squad2])
+    manager = orm.em.fork()
+
+    const team = await manager.findOne(
+      Team,
+      {
+        id: team1.id,
+      },
+      {
+        populate: ["users"],
+      }
+    )
+
+    const serializedSquad = mikroOrmSerializer<InstanceType<typeof Team>>(team)
+
+    expect(serializedSquad.users).toHaveLength(2)
+    expect(serializedSquad).toEqual({
+      id: team1.id,
+      name: "Team 1",
+      created_at: expect.any(Date),
+      updated_at: expect.any(Date),
+      deleted_at: null,
+      users: expect.arrayContaining([
+        {
+          id: user1.id,
+          username: "User 1",
+          created_at: expect.any(Date),
+          updated_at: expect.any(Date),
+          deleted_at: null,
+        },
+        {
+          id: user2.id,
+          username: "User 2",
+          created_at: expect.any(Date),
+          updated_at: expect.any(Date),
+          deleted_at: null,
+        },
+      ]),
+    })
+
+    const user = await manager.findOne(
+      User,
+      {
+        id: user1.id,
+      },
+      {
+        populate: ["squads"],
+      }
+    )
+
+    const serializedUser = mikroOrmSerializer<InstanceType<typeof User>>(user)
+
+    expect(serializedUser.squads).toHaveLength(1)
+    expect(serializedUser).toEqual({
+      id: user1.id,
+      username: "User 1",
+      created_at: expect.any(Date),
+      updated_at: expect.any(Date),
+      deleted_at: null,
+      squads: expect.arrayContaining([
+        {
+          id: team1.id,
+          name: "Team 1",
+          created_at: expect.any(Date),
+          updated_at: expect.any(Date),
+          deleted_at: null,
+        },
+      ]),
+    })
+  })
+})
--- a/packages/core/utils/src/dml/integration-tests/many-to-one.spec.ts
+++ b/packages/core/utils/src/dml/integration-tests/many-to-one.spec.ts
@@ -0,0 +1,152 @@
+import { MetadataStorage, MikroORM } from "@mikro-orm/core"
+import { model } from "../entity-builder"
+import { toMikroOrmEntities } from "../helpers/create-mikro-orm-entity"
+import { createDatabase, dropDatabase } from "pg-god"
+import { mikroOrmSerializer } from "../../dal"
+import { FileSystem } from "../../common"
+import { join } from "path"
+import { EntityConstructor } from "@medusajs/types"
+
+const DB_HOST = process.env.DB_HOST
+const DB_USERNAME = process.env.DB_USERNAME
+const DB_PASSWORD = process.env.DB_PASSWORD
+
+const pgGodCredentials = {
+  user: DB_USERNAME,
+  password: DB_PASSWORD,
+  host: DB_HOST,
+}
+
+const fileSystem = new FileSystem(join(__dirname, "../../migrations"))
+
+describe("manyToOne - belongTo", () => {
+  const dbName = "EntityBuilder-ManyToOne"
+
+  let orm!: MikroORM
+  let Team: EntityConstructor<any>, User: EntityConstructor<any>
+
+  afterAll(() => {
+    fileSystem.cleanup()
+  })
+
+  beforeEach(async () => {
+    MetadataStorage.clear()
+
+    const team = model.define("team", {
+      id: model.id(),
+      name: model.text(),
+      user: model.belongsTo(() => user, { mappedBy: "teams" }),
+    })
+
+    const user = model.define("user", {
+      id: model.id(),
+      username: model.text(),
+      teams: model.hasMany(() => team, { mappedBy: "user" }),
+    })
+
+    ;[User, Team] = toMikroOrmEntities([user, team])
+
+    await createDatabase({ databaseName: dbName }, pgGodCredentials)
+
+    orm = await MikroORM.init({
+      entities: [Team, User],
+      tsNode: true,
+      dbName,
+      debug: true,
+      type: "postgresql",
+    })
+
+    const migrator = orm.getMigrator()
+    await migrator.createMigration()
+    await migrator.up()
+  })
+
+  afterEach(async () => {
+    await orm.close()
+
+    await dropDatabase(
+      { databaseName: dbName, errorIfNonExist: false },
+      pgGodCredentials
+    )
+  })
+
+  it(`should handle the relation properly`, async () => {
+    let manager = orm.em.fork()
+
+    const user1 = manager.create(User, {
+      username: "User 1",
+    })
+    const user2 = manager.create(User, {
+      username: "User 2",
+    })
+
+    await manager.persistAndFlush([user1, user2])
+    manager = orm.em.fork()
+
+    const team1 = manager.create(Team, {
+      name: "Team 1",
+      user_id: user1.id,
+    })
+    const team2 = manager.create(Team, {
+      name: "Team 2",
+      user_id: user2.id,
+    })
+
+    await manager.persistAndFlush([team1, team2])
+    manager = orm.em.fork()
+
+    const team = await manager.findOne(
+      Team,
+      {
+        id: team1.id,
+      },
+      {
+        populate: ["user"],
+      }
+    )
+
+    expect(mikroOrmSerializer<InstanceType<typeof Team>>(team)).toEqual({
+      id: team1.id,
+      name: "Team 1",
+      created_at: expect.any(Date),
+      updated_at: expect.any(Date),
+      deleted_at: null,
+      user_id: user1.id,
+      user: {
+        id: user1.id,
+        username: "User 1",
+        created_at: expect.any(Date),
+        updated_at: expect.any(Date),
+        deleted_at: null,
+      },
+    })
+
+    const user = await manager.findOne(
+      User,
+      {
+        id: user1.id,
+      },
+      {
+        populate: ["teams"],
+      }
+    )
+
+    expect(mikroOrmSerializer<InstanceType<typeof User>>(user)).toEqual({
+      id: user1.id,
+      username: "User 1",
+      created_at: expect.any(Date),
+      updated_at: expect.any(Date),
+      deleted_at: null,
+      teams: [
+        {
+          id: team1.id,
+          name: "Team 1",
+          created_at: expect.any(Date),
+          updated_at: expect.any(Date),
+          deleted_at: null,
+          user_id: user1.id,
+        },
+      ],
+    })
+  })
+})
--- a/packages/core/utils/src/modules-sdk/index.ts
+++ b/packages/core/utils/src/modules-sdk/index.ts
@@ -13,3 +13,4 @@ export * from "./medusa-internal-service"
 export * from "./medusa-service"
 export * from "./migration-scripts"
 export * from "./mikro-orm-cli-config-builder"
+
--- a/packages/core/utils/src/modules-sdk/mikro-orm-cli-config-builder.ts
+++ b/packages/core/utils/src/modules-sdk/mikro-orm-cli-config-builder.ts
@@ -1,8 +1,12 @@
 import { MikroORMOptions } from "@mikro-orm/core/utils/Configuration"
 import { DmlEntity, toMikroORMEntity } from "../dml"
 import { TSMigrationGenerator } from "../dal"
-import { AnyEntity, EntityClassGroup, EntitySchema } from "@mikro-orm/core"
-import { EntityClass } from "@mikro-orm/core/typings"
+import type {
+  AnyEntity,
+  EntityClass,
+  EntityClassGroup,
+} from "@mikro-orm/core/typings"
+import type { EntitySchema } from "@mikro-orm/core/metadata/EntitySchema"

 type Options = Partial<MikroORMOptions> & {
  entities: (
--- a/packages/modules/fulfillment/mikro-orm.config.dev.ts
+++ b/packages/modules/fulfillment/mikro-orm.config.dev.ts
@@ -1,12 +1,7 @@
 import * as entities from "./src/models"
-import { TSMigrationGenerator } from "@medusajs/utils"
+import { defineMikroOrmCliConfig } from "@medusajs/utils"

-module.exports = {
+module.exports = defineMikroOrmCliConfig({
  entities: Object.values(entities),
-  schema: "public",
-  clientUrl: "postgres://postgres@localhost/medusa-fulfillment",
-  type: "postgresql",
-  migrations: {
-    generator: TSMigrationGenerator,
-  },
-}
+  databaseName: "medusa-fulfillment",
+})