chore(utils): Provide a mikro orm base entity (medusajs#7286)

**What**
Provide a new mikro orm base entity in order to abstract away the on init and on create which include the id auto generation if not provided. The main goal is to reduce complexity in entity definition

.changeset/old-candles-cough.md

@@ -0,0 +1,5 @@
+---
+"@medusajs/utils": patch
+---
+
+chore(utils): Provide a mikro orm base entity

packages/core/utils/src/dal/index.ts

@@ -4,7 +4,7 @@ export * from "./mikro-orm/mikro-orm-free-text-search-filter"
 export * from "./mikro-orm/mikro-orm-repository"
 export * from "./mikro-orm/mikro-orm-soft-deletable-filter"
 export * from "./mikro-orm/mikro-orm-serializer"
+export * from "./mikro-orm/base-entity"
 export * from "./mikro-orm/utils"
 export * from "./mikro-orm/decorators/searchable"
-export * from "./repositories"
 export * from "./utils"

packages/core/utils/src/dal/mikro-orm/__tests__/base-entity.spec.ts

@@ -0,0 +1,130 @@
+import { Entity, MikroORM, OnInit, Property } from "@mikro-orm/core"
+import { BaseEntity } from "../base-entity"
+
+describe("BaseEntity", () => {
+  it("should handle the id generation using the provided prefix", async () => {
+    @Entity()
+    class Entity1 extends BaseEntity {
+      constructor() {
+        super({ prefix_id: "prod" })
+      }
+    }
+
+    const orm = await MikroORM.init({
+      entities: [Entity1],
+      dbName: "test",
+      type: "postgresql",
+    })
+
+    const manager = orm.em.fork()
+    const entity1 = manager.create(Entity1, {})
+
+    expect(entity1.id).toMatch(/prod_[0-9]/)
+
+    await orm.close()
+  })
+
+  it("should handle the id generation without a provided prefix using the first three letter of the entity lower cased", async () => {
+    @Entity()
+    class Entity1 extends BaseEntity {}
+
+    const orm = await MikroORM.init({
+      entities: [Entity1],
+      dbName: "test",
+      type: "postgresql",
+    })
+
+    const manager = orm.em.fork()
+    const entity1 = manager.create(Entity1, {})
+
+    expect(entity1.id).toMatch(/ent_[0-9]/)
+
+    await orm.close()
+  })
+
+  it("should handle the id generation without a provided prefix inferring it based on the words composing the entity name excluding model and entity as part of the name", async () => {
+    @Entity()
+    class ProductModel extends BaseEntity {}
+
+    @Entity()
+    class ProductCategoryEntity extends BaseEntity {}
+
+    @Entity()
+    class ProductOptionValue extends BaseEntity {}
+
+    const orm = await MikroORM.init({
+      entities: [ProductModel, ProductCategoryEntity, ProductOptionValue],
+      dbName: "test",
+      type: "postgresql",
+    })
+
+    const manager = orm.em.fork()
+
+    const product = manager.create(ProductModel, {})
+    const productCategory = manager.create(ProductCategoryEntity, {})
+    const productOptionValue = manager.create(ProductOptionValue, {})
+
+    expect(product.id).toMatch(/pro_[0-9]/)
+    expect(productCategory.id).toMatch(/prc_[0-9]/)
+    expect(productOptionValue.id).toMatch(/pov_[0-9]/)
+
+    await orm.close()
+  })
+
+  it("should handle the id generation even with custom onInit or beforeCreate", async () => {
+    @Entity()
+    class ProductModel extends BaseEntity {
+      @Property()
+      custom_prop: string
+
+      @OnInit()
+      onInit() {
+        this.custom_prop = "custom"
+      }
+    }
+
+    @Entity()
+    class ProductCategoryEntity extends BaseEntity {
+      @Property()
+      custom_prop: string
+
+      @OnInit()
+      onInit() {
+        this.custom_prop = "custom"
+      }
+    }
+
+    @Entity()
+    class ProductOptionValue extends BaseEntity {
+      @Property()
+      custom_prop: string
+
+      @OnInit()
+      onInit() {
+        this.custom_prop = "custom"
+      }
+    }
+
+    const orm = await MikroORM.init({
+      entities: [ProductModel, ProductCategoryEntity, ProductOptionValue],
+      dbName: "test",
+      type: "postgresql",
+    })
+
+    const manager = orm.em.fork()
+
+    const product = manager.create(ProductModel, {})
+    const productCategory = manager.create(ProductCategoryEntity, {})
+    const productOptionValue = manager.create(ProductOptionValue, {})
+
+    expect(product.id).toMatch(/pro_[0-9]/)
+    expect(productCategory.id).toMatch(/prc_[0-9]/)
+    expect(productOptionValue.id).toMatch(/pov_[0-9]/)
+
+    expect(product.custom_prop).toBe("custom")
+    expect(productCategory.custom_prop).toBe("custom")
+    expect(productOptionValue.custom_prop).toBe("custom")
+
+    await orm.close()
+  })
+})

packages/core/utils/src/dal/mikro-orm/base-entity.ts

@@ -0,0 +1,68 @@
+import {
+  BeforeCreate,
+  Entity,
+  OnInit,
+  OptionalProps,
+  PrimaryKey,
+} from "@mikro-orm/core"
+import { generateEntityId } from "../../common"
+
+@Entity({ abstract: true })
+export class BaseEntity {
+  [OptionalProps]?: BaseEntity["id"] | BaseEntity["__prefix_id__"]
+
+  private __prefix_id__?: string
+
+  constructor({ prefix_id }: { prefix_id?: string } = {}) {
+    this.__prefix_id__ = prefix_id
+  }
+
+  @PrimaryKey({ columnType: "text" })
+  id!: string
+
+  @OnInit()
+  @BeforeCreate()
+  onInitOrBeforeCreate_() {
+    this.id ??= this.generateEntityId(this.__prefix_id__)
+  }
+
+  private generateEntityId(prefixId?: string): string {
+    if (prefixId) {
+      return generateEntityId(undefined, prefixId)
+    }
+
+    let ensuredPrefixId = Object.getPrototypeOf(this).constructor.name as string
+
+    /*
+     * Split the class name (camel case) into words and exclude model and entity from the words
+     */
+    const words = ensuredPrefixId
+      .split(/(?=[A-Z])/)
+      .filter((word) => !["entity", "model"].includes(word.toLowerCase()))
+    const wordsLength = words.length
+
+    /*
+     * if the class name (camel case) contains one word, the prefix id is the first three letters of the word
+     * if the class name (camel case) contains two words, the prefix id is the first two letters of the first word plus the first letter of the second one
+     * if the class name (camel case) contains more than two words, the prefix id is the first letter of each word
+     */
+    if (wordsLength === 1) {
+      ensuredPrefixId = words[0].substring(0, 3)
+    } else if (wordsLength === 2) {
+      ensuredPrefixId = words
+        .map((word, index) => {
+          return word.substring(0, 2 - index)
+        })
+        .join("")
+    } else {
+      ensuredPrefixId = words
+        .map((word) => {
+          return word[0]
+        })
+        .join("")
+    }
+
+    this.__prefix_id__ = ensuredPrefixId.toLowerCase()
+    return generateEntityId(undefined, this.__prefix_id__)
+  }
+}