chore(medusa, interfaces): Uniformise class checks (#5869)

**What**
One problem with local development can be the dependencies management. To mitigate that, transform checks from an instance of to value check as well as harmonize utils function to be part of the class as a static method instead of separate utilities. By using this approach we are not dependent of the origin of the class and therefore it should ease the user experience.

**NOTE**
As a next step to discuss, we should probably move the interfaces from the interfaces/medusa package to the utils package. Then we can deprecate the interfaces package and remove it at a later time

.changeset/bright-coins-kneel.md

@@ -0,0 +1,8 @@
+---
+"@medusajs/medusa": patch
+"medusa-fulfillment-webshipper": patch
+"medusa-interfaces": patch
+"@medusajs/utils": patch
+---
+
+chore(medusa, interfaces, utils, webshiper): Uniformise class checks

packages/medusa-fulfillment-webshipper/src/services/webshipper-fulfillment.js

@@ -10,7 +10,7 @@ class WebshipperFulfillmentService extends AbstractFulfillmentService {
     { logger, totalsService, claimService, swapService, orderService },
     options
   ) {
-    super()
+    super(...arguments)
 
     this.options_ = options
 

packages/medusa-interfaces/src/file-service.js

@@ -3,8 +3,15 @@ import BaseService from "./base-service"
 /**
  * Interface for file connectors
  * @interface
+ * @deprecated use AbstractFileService from @medusajs/medusa instead
  */
 class BaseFileService extends BaseService {
+  static _isFileService = true
+
+  static isFileService(obj) {
+    return obj?.constructor?._isFileService
+  }
+
   constructor() {
     super()
   }

packages/medusa-interfaces/src/fulfillment-service.js

@@ -5,8 +5,15 @@ import BaseService from "./base-service"
  * provides the necessary methods for creating, authorizing and managing
  * fulfillment orders.
  * @interface
+ * @deprecated use AbstractFulfillmentService from @medusajs/medusa instead
  */
 class BaseFulfillmentService extends BaseService {
+  static _isFulfillmentService = true
+
+  static isFulfillmentService(obj) {
+    return obj?.constructor?._isFulfillmentService
+  }
+
   constructor() {
     super()
   }
@@ -102,7 +109,7 @@ class BaseFulfillmentService extends BaseService {
     return []
   }
 
-  retrieveDocuments(fulfillmentData, documentType) { 
+  retrieveDocuments(fulfillmentData, documentType) {
     throw Error("retrieveDocuments must be overridden by the child class")
   }
 }

packages/medusa-interfaces/src/notification-service.js

@@ -3,8 +3,15 @@ import BaseService from "./base-service"
 /**
  * Interface for Notification Providers
  * @interface
+ * @deprecated use AbstractNotificationService from @medusajs/medusa instead
  */
 class BaseNotificationService extends BaseService {
+  static _isNotificationService = true
+
+  static isNotificationService(obj) {
+    return obj?.constructor?._isNotificationService
+  }
+
   constructor() {
     super()
   }

packages/medusa-interfaces/src/oauth-service.js

@@ -5,6 +5,12 @@ import BaseService from "./base-service"
  * @interface
  */
 class BaseOauthService extends BaseService {
+  static _isOauthService = true
+
+  static isOauthService(obj) {
+    return obj?.constructor?._isOauthService
+  }
+
   constructor() {
     super()
   }

packages/medusa-interfaces/src/payment-service.js

@@ -5,8 +5,15 @@ import BaseService from "./base-service"
  * provides the necessary methods for creating, authorizing and managing
  * payments.
  * @interface
+ * @deprecated use AbstractPaymentProcessor from @medusajs/medusa instead
  */
 class BasePaymentService extends BaseService {
+  static _isPaymentService = true
+
+  static isPaymentService(obj) {
+    return obj?.constructor?._isPaymentService
+  }
+
   constructor() {
     super()
   }

packages/medusa-interfaces/src/search-service.js

@@ -3,8 +3,15 @@ import BaseService from "./base-service"
 /**
  * The interface that all search services must implement.
  * @interface
+ * @deprecated use AbstractSearchService from @medusajs/utils instead
  */
 class SearchService extends BaseService {
+  static _isSearchService = true
+
+  static isSearchService(obj) {
+    return obj?.constructor?._isSearchService
+  }
+
   constructor() {
     super()
   }

packages/medusa/src/interfaces/batch-job-strategy.ts

@@ -33,11 +33,16 @@ export abstract class AbstractBatchJobStrategy
   extends TransactionBaseService
   implements IBatchJobStrategy
 {
+  static _isBatchJobStrategy = true
   static identifier: string
   static batchType: string
 
   protected abstract batchJobService_: BatchJobService
 
+  static isBatchJobStrategy(object): object is IBatchJobStrategy {
+    return object?.constructor?._isBatchJobStrategy
+  }
+
   async prepareBatchJobForProcessing(
     batchJob: CreateBatchJobInput,
     // eslint-disable-next-line @typescript-eslint/no-unused-vars
@@ -107,9 +112,3 @@ export abstract class AbstractBatchJobStrategy
     })
   }
 }
-
-export function isBatchJobStrategy(
-  object: unknown
-): object is IBatchJobStrategy {
-  return object instanceof AbstractBatchJobStrategy
-}

packages/medusa/src/interfaces/cart-completion-strategy.ts

@@ -30,16 +30,15 @@ export abstract class AbstractCartCompletionStrategy
   extends TransactionBaseService
   implements ICartCompletionStrategy
 {
+  static _isCartCompletionStrategy = true
+
+  static isCartCompletionStrategy(object): object is ICartCompletionStrategy {
+    return object?.constructor?._isCartCompletionStrategy
+  }
+
   abstract complete(
     cartId: string,
     idempotencyKey: IdempotencyKey,
     context: RequestContext
   ): Promise<CartCompletionResponse>
 }
-
-export function isCartCompletionStrategy(obj: unknown): boolean {
-  return (
-    typeof (obj as AbstractCartCompletionStrategy).complete === "function" ||
-    obj instanceof AbstractCartCompletionStrategy
-  )
-}

packages/medusa/src/interfaces/file-service.ts

@@ -55,6 +55,12 @@ export abstract class AbstractFileService
   extends TransactionBaseService
   implements IFileService
 {
+  static _isFileService = true
+
+  static isFileService(object): object is AbstractFileService {
+    return object?.constructor?._isFileService
+  }
+
   abstract upload(
     fileData: Express.Multer.File
   ): Promise<FileServiceUploadResult>
@@ -77,7 +83,3 @@ export abstract class AbstractFileService
     fileData: GetUploadedFileType
   ): Promise<string>
 }
-
-export const isFileService = (object: unknown): boolean => {
-  return object instanceof AbstractFileService
-}

packages/medusa/src/interfaces/fulfillment-service.ts

@@ -1,6 +1,7 @@
 import { MedusaContainer } from "@medusajs/types"
 import { Cart, Fulfillment, LineItem, Order } from "../models"
 import { CreateReturnType } from "../types/fulfillment-provider"
+import { TransactionBaseService } from "./transaction-base-service"
 
 type FulfillmentProviderData = Record<string, unknown>
 type ShippingOptionData = Record<string, unknown>
@@ -44,7 +45,7 @@ type ShippingMethodData = Record<string, unknown>
  *
  * ---
  */
-export interface FulfillmentService {
+export interface FulfillmentService extends TransactionBaseService {
   /**
    * @ignore
    *
@@ -389,7 +390,16 @@ export interface FulfillmentService {
   ): Promise<any>
 }
 
-export abstract class AbstractFulfillmentService implements FulfillmentService {
+export abstract class AbstractFulfillmentService
+  extends TransactionBaseService
+  implements FulfillmentService
+{
+  static _isFulfillmentService = true
+
+  static isFulfillmentService(object): boolean {
+    return object?.constructor?._isFulfillmentService
+  }
+
   /**
    * You can use the `constructor` of your fulfillment provider to access the different services in Medusa through dependency injection.
    * You can also use the constructor to initialize your integration with the third-party provider. For example, if you use a client to connect to the third-party provider’s APIs, you can initialize it in the constructor and use it in other methods in the service.
@@ -415,7 +425,9 @@ export abstract class AbstractFulfillmentService implements FulfillmentService {
   protected constructor(
     protected readonly container: MedusaContainer,
     protected readonly config?: Record<string, unknown> // eslint-disable-next-line @typescript-eslint/no-empty-function
-  ) {}
+  ) {
+    super(container, config)
+  }
 
   /**
    * The `FulfillmentProvider` entity has 2 properties: `identifier` and `is_installed`. The `identifier` property in the class is used when the fulfillment provider is created in the database.

packages/medusa/src/interfaces/notification-service.ts

@@ -1,5 +1,4 @@
 import { TransactionBaseService } from "./transaction-base-service"
-import BaseNotificationService from "medusa-interfaces/dist/notification-service"
 
 type ReturnedData = {
   to: string
@@ -25,8 +24,13 @@ export abstract class AbstractNotificationService
   extends TransactionBaseService
   implements INotificationService
 {
+  static _isNotificationService = true
   static identifier: string
 
+  static isNotificationService(object): boolean {
+    return object?.constructor?._isNotificationService
+  }
+
   getIdentifier(): string {
     return (this.constructor as any).identifier
   }
@@ -43,10 +47,3 @@ export abstract class AbstractNotificationService
     attachmentGenerator: unknown
   ): Promise<ReturnedData>
 }
-
-export const isNotificationService = (obj: unknown): boolean => {
-  return (
-    obj instanceof AbstractNotificationService ||
-    obj instanceof BaseNotificationService
-  )
-}

packages/medusa/src/interfaces/payment-processor.ts

@@ -676,6 +676,12 @@ export abstract class AbstractPaymentProcessor implements PaymentProcessor {
     protected readonly config?: Record<string, unknown> // eslint-disable-next-line @typescript-eslint/no-empty-function
   ) {}
 
+  static _isPaymentProcessor = true
+
+  static isPaymentProcessor(object): boolean {
+    return object?.constructor?._isPaymentProcessor
+  }
+
   /**
    * The `PaymentProvider` entity has 2 properties: `id` and `is_installed`. The `identifier` property in the payment processor service is used when the payment processor is added to the database.
    *
@@ -768,18 +774,6 @@ export abstract class AbstractPaymentProcessor implements PaymentProcessor {
   >
 }
 
-/**
- * Return if the input object is AbstractPaymentProcessor
- * @param obj
- */
-export function isPaymentProcessor(obj: unknown): boolean {
-  return obj instanceof AbstractPaymentProcessor
-}
-
-/**
- * Utility function to determine if an object is a processor error
- * @param obj
- */
 export function isPaymentProcessorError(
   obj: any
 ): obj is PaymentProcessorError {

packages/medusa/src/interfaces/payment-service.ts

@@ -146,6 +146,12 @@ export abstract class AbstractPaymentService
   extends TransactionBaseService
   implements PaymentService
 {
+  static _isPaymentService = true
+
+  static isPaymentService(object): boolean {
+    return object?.constructor?._isPaymentService
+  }
+
   protected constructor(container: unknown, config?: Record<string, unknown>) {
     super(container, config)
   }
@@ -258,11 +264,3 @@ export abstract class AbstractPaymentService
    */
   public abstract getStatus(data: Data): Promise<PaymentSessionStatus>
 }
-
-/**
- * Return if the input object is one of AbstractPaymentService or PaymentService or AbstractPaymentPluginService
- * @param obj
- */
-export function isPaymentService(obj: unknown): boolean {
-  return obj instanceof AbstractPaymentService || obj instanceof PaymentService
-}

packages/medusa/src/interfaces/price-selection-strategy.ts

@@ -32,6 +32,12 @@ export abstract class AbstractPriceSelectionStrategy
   extends TransactionBaseService
   implements IPriceSelectionStrategy
 {
+  static _isPriceSelectionStrategy = true
+
+  static isPriceSelectionStrategy(object): boolean {
+    return object?.constructor?._isPriceSelectionStrategy
+  }
+
   public abstract calculateVariantPrice(
     data: {
       variantId: string
@@ -46,16 +52,6 @@ export abstract class AbstractPriceSelectionStrategy
   }
 }
 
-export function isPriceSelectionStrategy(
-  // eslint-disable-next-line @typescript-eslint/no-explicit-any
-  object: any
-): object is IPriceSelectionStrategy {
-  return (
-    typeof object.calculateVariantPrice === "function" &&
-    typeof object.withTransaction === "function"
-  )
-}
-
 export type PriceSelectionContext = {
   cart_id?: string
   customer_id?: string

packages/medusa/src/interfaces/tax-calculation-strategy.ts

@@ -2,6 +2,7 @@ import { LineItem } from "../models/line-item"
 import { TaxCalculationContext } from "./tax-service"
 import { LineItemTaxLine } from "../models/line-item-tax-line"
 import { ShippingMethodTaxLine } from "../models/shipping-method-tax-line"
+import { TransactionBaseService } from "./transaction-base-service"
 
 export interface ITaxCalculationStrategy {
   /**
@@ -19,9 +20,22 @@ export interface ITaxCalculationStrategy {
   ): Promise<number>
 }
 
-export function isTaxCalculationStrategy(
-  // eslint-disable-next-line @typescript-eslint/no-explicit-any
-  object: any
-): object is ITaxCalculationStrategy {
-  return typeof object.calculate === "function"
+export abstract class AbstractTaxCalculationStrategy
+  extends TransactionBaseService
+  implements ITaxCalculationStrategy
+{
+  static _isTaxCalculationStrategy = true
+
+  static isTaxCalculationStrategy(object): boolean {
+    return (
+      typeof object.calculate === "function" ||
+      object?.constructor?._isTaxCalculationStrategy
+    )
+  }
+
+  abstract calculate(
+    items: LineItem[],
+    taxLines: (ShippingMethodTaxLine | LineItemTaxLine)[],
+    calculationContext: TaxCalculationContext
+  ): Promise<number>
 }

packages/medusa/src/interfaces/tax-service.ts

@@ -1,5 +1,3 @@
-import { BaseService } from "medusa-interfaces"
-
 import { LineItem } from "../models/line-item"
 import { Region } from "../models/region"
 import { Address } from "../models/address"
@@ -7,6 +5,7 @@ import { ShippingMethod } from "../models/shipping-method"
 import { Customer } from "../models/customer"
 import { ProviderTaxLine, TaxServiceRate } from "../types/tax-service"
 import { LineAllocationsMap } from "../types/totals"
+import { TransactionBaseService } from "./transaction-base-service"
 
 /**
  * A shipping method and the tax rates that have been configured to apply to the
@@ -61,11 +60,16 @@ export interface ITaxService {
 }
 
 export abstract class AbstractTaxService
-  extends BaseService
+  extends TransactionBaseService
   implements ITaxService
 {
+  static _isTaxService = true
   protected static identifier: string
 
+  static isTaxService(object): boolean {
+    return object?.constructor?._isTaxService
+  }
+
   public getIdentifier(): string {
     if (!(this.constructor as typeof AbstractTaxService).identifier) {
       throw new Error(`Missing static property "identifier".`)

packages/medusa/src/interfaces/transaction-base-service.ts

@@ -14,7 +14,7 @@ export abstract class TransactionBaseService {
     protected readonly __configModule__?: Record<string, unknown>,
     protected readonly __moduleDeclaration__?: Record<string, unknown>
   ) {
-    this.manager_ = __container__.manager
+    this.manager_ = __container__?.manager
   }
 
   withTransaction(transactionManager?: EntityManager): this {

packages/medusa/src/loaders/__tests__/plugins.spec.ts

@@ -9,7 +9,11 @@ import { createMedusaContainer } from "medusa-core-utils"
 import { resolve } from "path"
 import { DataSource, EntityManager } from "typeorm"
 import Logger from "../logger"
-import { MEDUSA_PROJECT_NAME, registerServices, registerStrategies } from "../plugins"
+import {
+  MEDUSA_PROJECT_NAME,
+  registerServices,
+  registerStrategies,
+} from "../plugins"
 
 // ***** TEMPLATES *****
 const buildServiceTemplate = (name: string): string => {
@@ -32,7 +36,7 @@ const buildBatchJobStrategyTemplate = (name: string, type: string): string => {
   return `
   import { AbstractBatchJobStrategy } from "../../../../interfaces/batch-job-strategy"
 
-  class ${name}BatchStrategy extends AbstractBatchJobStrategy{
+  class ${name}BatchStrategy extends AbstractBatchJobStrategy {
     static identifier = '${name}-identifier';
     static batchType = '${type}';
 
@@ -79,7 +83,8 @@ const buildPriceSelectionStrategyTemplate = (name: string): string => {
 
 const buildTaxCalcStrategyTemplate = (name: string): string => {
   return `
-  class ${name}TaxCalculationStrategy {
+  import { AbstractTaxCalculationStrategy } from "../../../../interfaces/tax-calculation-strategy"
+  class ${name}TaxCalculationStrategy extends AbstractTaxCalculationStrategy {
     calculate(items, taxLines, calculationContext) {
       throw new Error("Method not implemented.")
     }

packages/medusa/src/loaders/helpers/plugins.ts

@@ -1,13 +1,10 @@
-import { Lifetime, LifetimeType, aliasTo, asFunction } from "awilix"
-import { FulfillmentService } from "medusa-interfaces"
+import { aliasTo, asFunction, Lifetime, LifetimeType } from "awilix"
 import {
   AbstractFulfillmentService,
   AbstractPaymentProcessor,
-  AbstractPaymentService,
-  isPaymentProcessor,
-  isPaymentService,
 } from "../../interfaces"
 import { ClassConstructor, MedusaContainer } from "../../types/global"
+import { PaymentService } from "medusa-interfaces"
 
 type Context = {
   container: MedusaContainer
@@ -15,44 +12,16 @@ type Context = {
   registrationName: string
 }
 
-export function registerPaymentServiceFromClass(
-  klass: ClassConstructor<AbstractPaymentService> & {
-    LIFE_TIME?: LifetimeType
-  },
-  context: Context
-): void {
-  if (!isPaymentService(klass.prototype)) {
-    return
-  }
-
-  const { container, pluginDetails, registrationName } = context
-
-  container.registerAdd(
-    "paymentProviders",
-    asFunction((cradle) => new klass(cradle, pluginDetails.options), {
-      lifetime: klass.LIFE_TIME || Lifetime.SINGLETON,
-    })
-  )
-
-  container.register({
-    [registrationName]: asFunction(
-      (cradle) => new klass(cradle, pluginDetails.options),
-      {
-        lifetime: klass.LIFE_TIME || Lifetime.SINGLETON,
-      }
-    ),
-    [`pp_${(klass as unknown as typeof AbstractPaymentService).identifier}`]:
-      aliasTo(registrationName),
-  })
-}
-
 export function registerPaymentProcessorFromClass(
   klass: ClassConstructor<AbstractPaymentProcessor> & {
     LIFE_TIME?: LifetimeType
   },
   context: Context
 ): void {
-  if (!isPaymentProcessor(klass.prototype)) {
+  if (
+    !AbstractPaymentProcessor.isPaymentProcessor(klass.prototype) &&
+    !PaymentService.isPaymentService(klass.prototype)
+  ) {
     return
   }
 
@@ -83,7 +52,7 @@ export function registerAbstractFulfillmentServiceFromClass(
   },
   context: Context
 ): void {
-  if (!(klass.prototype instanceof AbstractFulfillmentService)) {
+  if (!AbstractFulfillmentService.isFulfillmentService(klass.prototype)) {
     return
   }
 
@@ -108,34 +77,3 @@ export function registerAbstractFulfillmentServiceFromClass(
     }`]: aliasTo(registrationName),
   })
 }
-
-export function registerFulfillmentServiceFromClass(
-  klass: ClassConstructor<typeof FulfillmentService> & {
-    LIFE_TIME?: LifetimeType
-  },
-  context: Context
-): void {
-  if (!(klass.prototype instanceof FulfillmentService)) {
-    return
-  }
-
-  const { container, pluginDetails, registrationName } = context
-
-  container.registerAdd(
-    "fulfillmentProviders",
-    asFunction((cradle) => new klass(cradle, pluginDetails.options), {
-      lifetime: klass.LIFE_TIME || Lifetime.SINGLETON,
-    })
-  )
-
-  container.register({
-    [registrationName]: asFunction(
-      (cradle) => new klass(cradle, pluginDetails.options),
-      {
-        lifetime: klass.LIFE_TIME || Lifetime.SINGLETON,
-      }
-    ),
-    [`fp_${(klass as unknown as typeof FulfillmentService).identifier}`]:
-      aliasTo(registrationName),
-  })
-}

packages/medusa/src/loaders/plugins.ts

@@ -1,4 +1,8 @@
-import { promiseAll, SearchUtils, upperCaseFirst } from "@medusajs/utils"
+import {
+  AbstractSearchService,
+  promiseAll,
+  upperCaseFirst,
+} from "@medusajs/utils"
 import { aliasTo, asFunction, asValue, Lifetime } from "awilix"
 import { Express } from "express"
 import fs from "fs"
@@ -6,19 +10,19 @@ import { sync as existsSync } from "fs-exists-cached"
 import glob from "glob"
 import _ from "lodash"
 import { createRequireFromPath } from "medusa-core-utils"
-import { FileService, OauthService } from "medusa-interfaces"
+import { OauthService } from "medusa-interfaces"
 import { trackInstallation } from "medusa-telemetry"
 import { EOL } from "os"
 import path from "path"
 import { EntitySchema } from "typeorm"
 import {
+  AbstractBatchJobStrategy,
+  AbstractCartCompletionStrategy,
+  AbstractFileService,
+  AbstractNotificationService,
+  AbstractPriceSelectionStrategy,
+  AbstractTaxCalculationStrategy,
   AbstractTaxService,
-  isBatchJobStrategy,
-  isCartCompletionStrategy,
-  isFileService,
-  isNotificationService,
-  isPriceSelectionStrategy,
-  isTaxCalculationStrategy,
 } from "../interfaces"
 import { MiddlewareService } from "../services"
 import {
@@ -35,9 +39,7 @@ import { getModelExtensionsMap } from "./helpers/get-model-extension-map"
 import ScheduledJobsLoader from "./helpers/jobs"
 import {
   registerAbstractFulfillmentServiceFromClass,
-  registerFulfillmentServiceFromClass,
   registerPaymentProcessorFromClass,
-  registerPaymentServiceFromClass,
 } from "./helpers/plugins"
 import { RoutesLoader } from "./helpers/routing"
 import { SubscriberLoader } from "./helpers/subscribers"
@@ -230,7 +232,9 @@ export function registerStrategies(
     const module = require(file).default
 
     switch (true) {
-      case isTaxCalculationStrategy(module.prototype): {
+      case AbstractTaxCalculationStrategy.isTaxCalculationStrategy(
+        module.prototype
+      ): {
         if (!("taxCalculationStrategy" in registeredServices)) {
           container.register({
             taxCalculationStrategy: asFunction(
@@ -246,7 +250,9 @@ export function registerStrategies(
         break
       }
 
-      case isCartCompletionStrategy(module.prototype): {
+      case AbstractCartCompletionStrategy.isCartCompletionStrategy(
+        module.prototype
+      ): {
         if (!("cartCompletionStrategy" in registeredServices)) {
           container.register({
             cartCompletionStrategy: asFunction(
@@ -262,7 +268,7 @@ export function registerStrategies(
         break
       }
 
-      case isBatchJobStrategy(module.prototype): {
+      case AbstractBatchJobStrategy.isBatchJobStrategy(module.prototype): {
         container.registerAdd(
           "batchJobStrategies",
           asFunction((cradle) => new module(cradle, pluginDetails.options))
@@ -279,7 +285,9 @@ export function registerStrategies(
         break
       }
 
-      case isPriceSelectionStrategy(module.prototype): {
+      case AbstractPriceSelectionStrategy.isPriceSelectionStrategy(
+        module.prototype
+      ): {
         if (!("priceSelectionStrategy" in registeredServices)) {
           container.register({
             priceSelectionStrategy: asFunction(
@@ -441,8 +449,7 @@ async function registerApi(
 }
 
 /**
- * Registers a service at the right location in our container. If the service is
- * a BaseService instance it will be available directly from the container.
+ * Registers a service at the right location in our container.
  * PaymentService instances are added to the paymentProviders array in the
  * container. Names are camelCase formatted and namespaced by the folder i.e:
  * services/example-payments -> examplePaymentsService
@@ -464,13 +471,10 @@ export async function registerServices(
 
       const context = { container, pluginDetails, registrationName: name }
 
-      registerPaymentServiceFromClass(loaded, context)
       registerPaymentProcessorFromClass(loaded, context)
-
-      registerFulfillmentServiceFromClass(loaded, context)
       registerAbstractFulfillmentServiceFromClass(loaded, context)
 
-      if (loaded.prototype instanceof OauthService) {
+      if (OauthService.isOauthService(loaded.prototype)) {
         const appDetails = loaded.getAppDetails(pluginDetails.options)
 
         const oauthService =
@@ -486,7 +490,9 @@ export async function registerServices(
             }
           ),
         })
-      } else if (isNotificationService(loaded.prototype)) {
+      } else if (
+        AbstractNotificationService.isNotificationService(loaded.prototype)
+      ) {
         container.registerAdd(
           "notificationProviders",
           asFunction((cradle) => new loaded(cradle, pluginDetails.options), {
@@ -505,10 +511,7 @@ export async function registerServices(
           ),
           [`noti_${loaded.identifier}`]: aliasTo(name),
         })
-      } else if (
-        loaded.prototype instanceof FileService ||
-        isFileService(loaded.prototype)
-      ) {
+      } else if (AbstractFileService.isFileService(loaded.prototype)) {
         // Add the service directly to the container in order to make simple
         // resolution if we already know which file storage provider we need to use
         container.register({
@@ -520,7 +523,7 @@ export async function registerServices(
           ),
           [`fileService`]: aliasTo(name),
         })
-      } else if (SearchUtils.isSearchService(loaded.prototype)) {
+      } else if (AbstractSearchService.isSearchService(loaded.prototype)) {
         // Add the service directly to the container in order to make simple
         // resolution if we already know which search provider we need to use
         container.register({
@@ -534,7 +537,7 @@ export async function registerServices(
         })
 
         container.register(isSearchEngineInstalledResolutionKey, asValue(true))
-      } else if (loaded.prototype instanceof AbstractTaxService) {
+      } else if (AbstractTaxService.isTaxService(loaded.prototype)) {
         container.registerAdd(
           "taxProviders",
           asFunction((cradle) => new loaded(cradle, pluginDetails.options), {

packages/medusa/src/loaders/strategies.ts

@@ -3,9 +3,9 @@ import path from "path"
 import { aliasTo, asFunction } from "awilix"
 
 import formatRegistrationName from "../utils/format-registration-name"
-import { isBatchJobStrategy } from "../interfaces"
 import { MedusaContainer } from "../types/global"
 import { isDefined } from "medusa-core-utils"
+import { AbstractBatchJobStrategy } from "../interfaces"
 
 type LoaderOptions = {
   container: MedusaContainer
@@ -49,7 +49,7 @@ export default ({ container, configModule, isTest }: LoaderOptions): void => {
     const loaded = require(fn).default
     const name = formatRegistrationName(fn)
 
-    if (isBatchJobStrategy(loaded.prototype)) {
+    if (AbstractBatchJobStrategy.isBatchJobStrategy(loaded.prototype)) {
       container.registerAdd(
         "batchJobStrategies",
         asFunction((cradle) => new loaded(cradle, configModule))

packages/medusa/src/services/system-tax.ts

@@ -10,7 +10,7 @@ class SystemTaxService extends AbstractTaxService {
   static identifier = "system"
 
   constructor() {
-    super()
+    super({})
   }
 
   async getTaxLines(

packages/utils/src/search/abstract-service.ts

@@ -3,6 +3,12 @@ import { SearchTypes } from "@medusajs/types"
 export abstract class AbstractSearchService
   implements SearchTypes.ISearchService
 {
+  static _isSearchService = true
+
+  static isSearchService(obj) {
+    return obj?.constructor?._isSearchService
+  }
+
   abstract readonly isDefault
   protected readonly options_: Record<string, unknown>
 

packages/utils/src/search/index.ts

@@ -1,6 +1,4 @@
 export * from "./abstract-service"
-export * from "./is-search-service"
 export * from "./search-relations"
 export * from "./index-types"
 export * from "./variant-keys"
-

packages/utils/src/search/is-search-service.ts

@@ -1,5 +0,0 @@
-import { AbstractSearchService } from "./abstract-service"
-
-export function isSearchService(obj: unknown): boolean {
-  return obj instanceof AbstractSearchService
-}