Feat(medusa): implement feature flags (#1768)

* feat: add feature flag loading in projects

* fix: make feature flag consume itself

* fix: rename container registration to featureFlagRouter

* fix: refactor

* behavioral feature flags

* add environment to server

* limit "useTemplateDb" to non feature flagged migrations

* filter migrations and entities according to those which are enabled in the environment

* run only migrations that are enabled when running 'medusa migrations run'

* add logging to the featureflag loader

* initial implementation of featureFlagEntity

* column descriptors

* initial startServerWithEnv (to be refactored)

* update commands

* final touches

* update loaders to fix unit tests

* enable all batch job tests

* update seed method

* add api test capabilities

* revert batch job test

* revert formatting changes

* pr feedback

* pr feedback

* remove unused imports

* rename feature flag decorators

* pr feedback

Co-authored-by: Sebastian Rindom <skrindom@gmail.com>

integration-tests/api/__tests__/batch-jobs/api.js

@@ -95,25 +95,25 @@ describe("/admin/batch-jobs", () => {
             id: "job_5",
             created_at: expect.any(String),
             updated_at: expect.any(String),
-            created_by: "admin_user"
+            created_by: "admin_user",
           },
           {
             id: "job_3",
             created_at: expect.any(String),
             updated_at: expect.any(String),
-            created_by: "admin_user"
+            created_by: "admin_user",
           },
           {
             id: "job_2",
             created_at: expect.any(String),
             updated_at: expect.any(String),
-            created_by: "admin_user"
+            created_by: "admin_user",
           },
           {
             id: "job_1",
             created_at: expect.any(String),
             updated_at: expect.any(String),
-            created_by: "admin_user"
+            created_by: "admin_user",
           },
         ],
       })
@@ -121,7 +121,10 @@ describe("/admin/batch-jobs", () => {
 
     it("lists batch jobs created by the user and where completed_at is null ", async () => {
       const api = useApi()
-      const response = await api.get("/admin/batch-jobs?completed_at=null", adminReqConfig)
+      const response = await api.get(
+        "/admin/batch-jobs?completed_at=null",
+        adminReqConfig
+      )
 
       expect(response.status).toEqual(200)
       expect(response.data.batch_jobs.length).toEqual(3)

integration-tests/helpers/setup-server.js

@@ -2,7 +2,7 @@ const path = require("path")
 const { spawn } = require("child_process")
 const { setPort } = require("./use-api")
 
-module.exports = ({ cwd, redisUrl, uploadDir, verbose }) => {
+module.exports = ({ cwd, redisUrl, uploadDir, verbose, env }) => {
   const serverPath = path.join(__dirname, "test-server.js")
 
   // in order to prevent conflicts in redis, use a different db for each worker
@@ -21,6 +21,7 @@ module.exports = ({ cwd, redisUrl, uploadDir, verbose }) => {
         COOKIE_SECRET: "test",
         REDIS_URL: redisUrl ? redisUrlWithDatabase : undefined, // If provided, will use a real instance, otherwise a fake instance
         UPLOAD_DIR: uploadDir, // If provided, will be used for the fake local file service
+        ...env,
       },
       stdio: verbose
         ? ["inherit", "inherit", "inherit", "ipc"]

integration-tests/helpers/start-server-with-environment.js

@@ -0,0 +1,28 @@
+const setupServer = require("./setup-server")
+const { initDb } = require("./use-db")
+
+const startServerWithEnvironment = async ({ cwd, verbose, env }) => {
+  if (env) {
+    Object.entries(env).forEach(([key, value]) => {
+      process.env[key] = value
+    })
+  }
+
+  const dbConnection = await initDb({
+    cwd,
+  })
+
+  Object.entries(env).forEach(([key, value]) => {
+    delete process.env[key]
+  })
+
+  const medusaProcess = await setupServer({
+    cwd,
+    verbose,
+    env,
+  })
+
+  return [medusaProcess, dbConnection]
+}
+
+export default startServerWithEnvironment

integration-tests/helpers/use-db.js

@@ -79,6 +79,19 @@ const instance = DbTestUtil
 module.exports = {
   initDb: async function ({ cwd }) {
     const configPath = path.resolve(path.join(cwd, `medusa-config.js`))
+    const { projectConfig, featureFlags } = require(configPath)
+
+    const featureFlagsLoader = require(path.join(
+      cwd,
+      `node_modules`,
+      `@medusajs`,
+      `medusa`,
+      `dist`,
+      `loaders`,
+      `feature-flags`
+    )).default
+
+    const featureFlagsRouter = featureFlagsLoader({ featureFlags })
 
     const modelsLoader = require(path.join(
       cwd,
@@ -89,9 +102,9 @@ module.exports = {
       `loaders`,
       `models`
     )).default
+
     const entities = modelsLoader({}, { register: false })
 
-    const { projectConfig } = require(configPath)
     if (projectConfig.database_type === "sqlite") {
       connectionType = "sqlite"
       const dbConnection = await createConnection({
@@ -108,12 +121,48 @@ module.exports = {
 
       await dbFactory.createFromTemplate(databaseName)
 
+      // get migraitons with enabled featureflags
+      const migrationDir = path.resolve(
+        path.join(
+          cwd,
+          `node_modules`,
+          `@medusajs`,
+          `medusa`,
+          `dist`,
+          `migrations`,
+          `*.js`
+        )
+      )
+
+      const { getEnabledMigrations } = require(path.join(
+        cwd,
+        `node_modules`,
+        `@medusajs`,
+        `medusa`,
+        `dist`,
+        `commands`,
+        `utils`,
+        `get-migrations`
+      ))
+
+      const enabledMigrations = await getEnabledMigrations(
+        [migrationDir],
+        (flag) => featureFlagsRouter.isFeatureEnabled(flag)
+      )
+
+      const enabledEntities = entities.filter(
+        (e) => typeof e.isFeatureEnabled === "undefined" || e.isFeatureEnabled()
+      )
+
       const dbConnection = await createConnection({
         type: "postgres",
         url: DB_URL,
-        entities,
+        entities: enabledEntities,
+        migrations: enabledMigrations,
       })
 
+      await dbConnection.runMigrations()
+
       instance.setDb(dbConnection)
       return dbConnection
     }

integration-tests/helpers/use-template-db.js

@@ -31,10 +31,28 @@ class DatabaseFactory {
           `@medusajs`,
           `medusa`,
           `dist`,
-          `migrations`
+          `migrations`,
+          `*.js`
         )
       )
 
+      const { getEnabledMigrations } = require(path.join(
+        cwd,
+        `node_modules`,
+        `@medusajs`,
+        `medusa`,
+        `dist`,
+        `commands`,
+        `utils`,
+        `get-migrations`
+      ))
+
+      // filter migrations to only include those that dont have feature flags
+      const enabledMigrations = await getEnabledMigrations(
+        [migrationDir],
+        (flag) => false
+      )
+
       await dropDatabase(
         {
           databaseName: this.templateDbName,
@@ -51,7 +69,7 @@ class DatabaseFactory {
         type: "postgres",
         name: "templateConnection",
         url: `${DB_URL}/${this.templateDbName}`,
-        migrations: [`${migrationDir}/*.js`],
+        migrations: enabledMigrations,
       })
 
       await templateDbConnection.runMigrations()
@@ -92,7 +110,7 @@ class DatabaseFactory {
   }
 
   async destroy() {
-    let connection = await this.getMasterConnection()
+    const connection = await this.getMasterConnection()
 
     await connection.query(`DROP DATABASE IF EXISTS "${this.templateDbName}";`)
     await connection.close()

packages/medusa/src/api/middlewares/feature-flag-enabled.ts

@@ -0,0 +1,18 @@
+import { NextFunction, Request, Response } from "express"
+import { FlagRouter } from "../../utils/flag-router"
+
+export function isFeatureFlagEnabled(
+  flagKey: string
+): (req: Request, res: Response, next: NextFunction) => Promise<void> {
+  return async (req: Request, res: Response, next: NextFunction) => {
+    const featureFlagRouter = req.scope.resolve(
+      "featureFlagRouter"
+    ) as FlagRouter
+
+    if (!featureFlagRouter.isFeatureEnabled(flagKey)) {
+      res.sendStatus(404)
+    } else {
+      next()
+    }
+  }
+}

packages/medusa/src/commands/migrate.js

@@ -1,24 +1,27 @@
 import { createConnection } from "typeorm"
 import { getConfigFile } from "medusa-core-utils"
-
+import featureFlagLoader from "../loaders/feature-flags"
 import Logger from "../loaders/logger"
 
 import getMigrations from "./utils/get-migrations"
 
-const t = async function({ directory }) {
+const t = async function ({ directory }) {
   const args = process.argv
   args.shift()
   args.shift()
   args.shift()
 
   const { configModule } = getConfigFile(directory, `medusa-config`)
-  const migrationDirs = getMigrations(directory)
+
+  const featureFlagRouter = featureFlagLoader(configModule)
+
+  const enabledMigrations = await getMigrations(directory, featureFlagRouter)
 
   const connection = await createConnection({
     type: configModule.projectConfig.database_type,
     url: configModule.projectConfig.database_url,
     extra: configModule.projectConfig.database_extra || {},
-    migrations: migrationDirs,
+    migrations: enabledMigrations,
     logging: true,
   })
 

packages/medusa/src/commands/seed.js

@@ -9,9 +9,11 @@ import { track } from "medusa-telemetry"
 import Logger from "../loaders/logger"
 import loaders from "../loaders"
 
+import featureFlagLoader from "../loaders/feature-flags"
+
 import getMigrations from "./utils/get-migrations"
 
-const t = async function({ directory, migrate, seedFile }) {
+const t = async function ({ directory, migrate, seedFile }) {
   track("CLI_SEED")
   let resolvedPath = seedFile
 
@@ -28,9 +30,12 @@ const t = async function({ directory, migrate, seedFile }) {
   }
 
   const { configModule } = getConfigFile(directory, `medusa-config`)
+
+  const featureFlagRouter = featureFlagLoader(configModule)
+
   const dbType = configModule.projectConfig.database_type
   if (migrate && dbType !== "sqlite") {
-    const migrationDirs = getMigrations(directory)
+    const migrationDirs = await getMigrations(directory, featureFlagRouter)
     const connection = await createConnection({
       type: configModule.projectConfig.database_type,
       database: configModule.projectConfig.database_database,
@@ -61,7 +66,7 @@ const t = async function({ directory, migrate, seedFile }) {
   const shippingOptionService = container.resolve("shippingOptionService")
   const shippingProfileService = container.resolve("shippingProfileService")
 
-  await manager.transaction(async tx => {
+  await manager.transaction(async (tx) => {
     const { store, regions, products, shipping_options, users } = JSON.parse(
       fs.readFileSync(resolvedPath, `utf-8`)
     )
@@ -74,14 +79,14 @@ const t = async function({ directory, migrate, seedFile }) {
     }
 
     for (const u of users) {
-      let pass = u.password
+      const pass = u.password
       if (pass) {
         delete u.password
       }
       await userService.withTransaction(tx).create(u, pass)
     }
 
-    let regionIds = {}
+    const regionIds = {}
     for (const r of regions) {
       let dummyId
       if (!r.id || !r.id.startsWith("reg_")) {
@@ -126,7 +131,7 @@ const t = async function({ directory, migrate, seedFile }) {
 
       if (variants && variants.length) {
         const optionIds = p.options.map(
-          o => newProd.options.find(newO => newO.title === o.title).id
+          (o) => newProd.options.find((newO) => newO.title === o.title).id
         )
 
         for (const v of variants) {

packages/medusa/src/commands/utils/get-migrations.js

@@ -1,3 +1,4 @@
+import glob from "glob"
 import path from "path"
 import fs from "fs"
 import { isString } from "lodash"
@@ -33,7 +34,7 @@ function resolvePlugin(pluginName) {
           fs.readFileSync(`${resolvedPath}/package.json`, `utf-8`)
         )
         const name = packageJSON.name || pluginName
-        //warnOnIncompatiblePeerDependency(name, packageJSON)
+        // warnOnIncompatiblePeerDependency(name, packageJSON)
 
         return {
           resolve: resolvedPath,
@@ -86,11 +87,11 @@ function resolvePlugin(pluginName) {
   }
 }
 
-export default directory => {
+export default async (directory, featureFlagRouter) => {
   const { configModule } = getConfigFile(directory, `medusa-config`)
   const { plugins } = configModule
 
-  const resolved = plugins.map(plugin => {
+  const resolved = plugins.map((plugin) => {
     if (isString(plugin)) {
       return resolvePlugin(plugin)
     }
@@ -123,5 +124,26 @@ export default directory => {
     }
   }
 
-  return migrationDirs
+  return getEnabledMigrations(migrationDirs, (flag) =>
+    featureFlagRouter.isFeatureEnabled(flag)
+  )
+}
+
+export const getEnabledMigrations = (migrationDirs, isFlagEnabled) => {
+  const allMigrations = migrationDirs.flatMap((dir) => {
+    return glob.sync(dir)
+  })
+  return allMigrations
+    .map((file) => {
+      const loaded = require(file)
+      if (
+        typeof loaded.featureFlag === "undefined" ||
+        isFlagEnabled(loaded.featureFlag)
+      ) {
+        return file
+      }
+
+      return false
+    })
+    .filter(Boolean)
 }

packages/medusa/src/helpers/test-request.js

@@ -7,6 +7,7 @@ import supertest from "supertest"
 import querystring from "querystring"
 import apiLoader from "../loaders/api"
 import passportLoader from "../loaders/passport"
+import featureFlagLoader from "../loaders/feature-flags"
 import servicesLoader from "../loaders/services"
 import strategiesLoader from "../loaders/strategies"
 
@@ -24,17 +25,21 @@ const clientSessionOpts = {
 
 const config = {
   projectConfig: {
-    jwt_secret: 'supersecret',
-    cookie_secret: 'superSecret',
-    admin_cors: '',
-    store_cors: ''
-  }
+    jwt_secret: "supersecret",
+    cookie_secret: "superSecret",
+    admin_cors: "",
+    store_cors: "",
+  },
 }
 
 const testApp = express()
 
 const container = createContainer()
-container.register('configModule', asValue(config))
+
+const featureFlagRouter = featureFlagLoader(config)
+
+container.register("featureFlagRouter", asValue(featureFlagRouter))
+container.register("configModule", asValue(config))
 container.register({
   logger: asValue({
     error: () => {},
@@ -69,10 +74,16 @@ apiLoader({ container, app: testApp, configModule: config })
 const supertestRequest = supertest(testApp)
 
 export async function request(method, url, opts = {}) {
-  const { payload, query, headers = {} } = opts
+  const { payload, query, headers = {}, flags = [] } = opts
 
-  const queryParams = query && querystring.stringify(query);
-  const req = supertestRequest[method.toLowerCase()](`${url}${queryParams ? "?" + queryParams : ''}`)
+  flags.forEach((flag) => {
+    featureFlagRouter.setFlag(flag, true)
+  })
+
+  const queryParams = query && querystring.stringify(query)
+  const req = supertestRequest[method.toLowerCase()](
+    `${url}${queryParams ? "?" + queryParams : ""}`
+  )
   headers.Cookie = headers.Cookie || ""
   if (opts.adminSession) {
     if (opts.adminSession.jwt) {

packages/medusa/src/loaders/__tests__/feature-flags.spec.ts

@@ -0,0 +1,130 @@
+import { resolve } from "path"
+import { mkdirSync, rmSync, writeFileSync } from "fs"
+
+import loadFeatureFlags from "../feature-flags"
+
+const distTestTargetDirectorPath = resolve(__dirname, "__ff-test__")
+
+const getFolderTestTargetDirectoryPath = (folderName: string): string => {
+  return resolve(distTestTargetDirectorPath, folderName)
+}
+
+const buildFeatureFlag = (
+  key: string,
+  defaultVal: string | boolean
+): string => {
+  const snakeCaseKey = key.replace(/-/g, "_")
+
+  return `
+    export default {
+      description: "${key} descr",
+      key: "${snakeCaseKey}",
+      env_key: "MEDUSA_FF_${snakeCaseKey.toUpperCase()}",
+      default_val: ${defaultVal},
+    }
+  `
+}
+
+describe("feature flags", () => {
+  const OLD_ENV = { ...process.env }
+
+  beforeEach(() => {
+    jest.resetModules()
+    jest.clearAllMocks()
+
+    process.env = { ...OLD_ENV }
+
+    rmSync(distTestTargetDirectorPath, { recursive: true, force: true })
+
+    mkdirSync(getFolderTestTargetDirectoryPath("project"), {
+      mode: "777",
+      recursive: true,
+    })
+
+    mkdirSync(getFolderTestTargetDirectoryPath("flags"), {
+      mode: "777",
+      recursive: true,
+    })
+  })
+
+  afterAll(() => {
+    process.env = OLD_ENV
+    rmSync(distTestTargetDirectorPath, { recursive: true, force: true })
+  })
+
+  it("should load the flag from project", async () => {
+    writeFileSync(
+      resolve(getFolderTestTargetDirectoryPath("flags"), "flag-1.js"),
+      buildFeatureFlag("flag-1", true)
+    )
+
+    const flags = await loadFeatureFlags(
+      { featureFlags: { flag_1: false } },
+      undefined,
+      getFolderTestTargetDirectoryPath("flags")
+    )
+
+    expect(flags.isFeatureEnabled("flag_1")).toEqual(false)
+  })
+
+  it("should load the default feature flags", async () => {
+    writeFileSync(
+      resolve(getFolderTestTargetDirectoryPath("flags"), "flag-1.js"),
+      buildFeatureFlag("flag-1", true)
+    )
+
+    const flags = await loadFeatureFlags(
+      {},
+      undefined,
+      getFolderTestTargetDirectoryPath("flags")
+    )
+
+    expect(flags.isFeatureEnabled("flag_1")).toEqual(true)
+  })
+
+  it("should load the flag from env", async () => {
+    process.env.MEDUSA_FF_FLAG_1 = "false"
+
+    writeFileSync(
+      resolve(getFolderTestTargetDirectoryPath("flags"), "flag-1.js"),
+      buildFeatureFlag("flag-1", true)
+    )
+
+    const flags = await loadFeatureFlags(
+      {},
+      undefined,
+      getFolderTestTargetDirectoryPath("flags")
+    )
+
+    expect(flags.isFeatureEnabled("flag_1")).toEqual(false)
+  })
+
+  it("should load mix of flags", async () => {
+    process.env.MEDUSA_FF_FLAG_3 = "false"
+
+    writeFileSync(
+      resolve(getFolderTestTargetDirectoryPath("flags"), "flag-1.js"),
+      buildFeatureFlag("flag-1", true)
+    )
+
+    writeFileSync(
+      resolve(getFolderTestTargetDirectoryPath("flags"), "flag-2.js"),
+      buildFeatureFlag("flag-2", true)
+    )
+
+    writeFileSync(
+      resolve(getFolderTestTargetDirectoryPath("flags"), "flag-3.js"),
+      buildFeatureFlag("flag-3", true)
+    )
+
+    const flags = await loadFeatureFlags(
+      { featureFlags: { flag_2: false } },
+      undefined,
+      getFolderTestTargetDirectoryPath("flags")
+    )
+
+    expect(flags.isFeatureEnabled("flag_1")).toEqual(true)
+    expect(flags.isFeatureEnabled("flag_2")).toEqual(false)
+    expect(flags.isFeatureEnabled("flag_3")).toEqual(false)
+  })
+})

packages/medusa/src/loaders/config.ts

@@ -56,6 +56,7 @@ export default (rootDirectory: string): ConfigModule => {
       cookie_secret: cookie_secret ?? "supersecret",
       ...configModule?.projectConfig,
     },
+    featureFlags: configModule?.featureFlags ?? {},
     plugins: configModule?.plugins ?? [],
   }
 }

packages/medusa/src/loaders/feature-flags/index.ts

@@ -0,0 +1,68 @@
+import path from "path"
+import glob from "glob"
+
+import { FlagSettings } from "../../types/feature-flags"
+import { FlagRouter } from "../../utils/flag-router"
+import { Logger } from "../../types/global"
+
+const isTruthy = (val: string | boolean | undefined): boolean => {
+  if (typeof val === "string") {
+    return val.toLowerCase() === "true"
+  }
+  return !!val
+}
+
+export default (
+  configModule: { featureFlags?: Record<string, string | boolean> } = {},
+  logger?: Logger,
+  flagDirectory?: string
+): FlagRouter => {
+  const { featureFlags: projectConfigFlags = {} } = configModule
+
+  const flagDir = path.join(flagDirectory || __dirname, "*.js")
+  const supportedFlags = glob.sync(flagDir, {
+    ignore: ["**/index.js"],
+  })
+
+  const flagConfig: Record<string, boolean> = {}
+  for (const flag of supportedFlags) {
+    // eslint-disable-next-line @typescript-eslint/no-var-requires
+    const importedModule = require(flag)
+    if (!importedModule.default) {
+      continue
+    }
+
+    const flagSettings: FlagSettings = importedModule.default
+
+    switch (true) {
+      case typeof process.env[flagSettings.env_key] !== "undefined":
+        if (logger) {
+          logger.info(
+            `Using flag ${flagSettings.env_key} from environment with value ${
+              process.env[flagSettings.env_key]
+            }`
+          )
+        }
+        flagConfig[flagSettings.key] = isTruthy(
+          process.env[flagSettings.env_key]
+        )
+        break
+      case typeof projectConfigFlags[flagSettings.key] !== "undefined":
+        if (logger) {
+          logger.info(
+            `Using flag ${flagSettings.key} from project config with value ${
+              projectConfigFlags[flagSettings.key]
+            }`
+          )
+        }
+        flagConfig[flagSettings.key] = isTruthy(
+          projectConfigFlags[flagSettings.key]
+        )
+        break
+      default:
+        flagConfig[flagSettings.key] = flagSettings.default_val
+    }
+  }
+
+  return new FlagRouter(flagConfig)
+}

packages/medusa/src/loaders/index.ts

@@ -1,10 +1,11 @@
-import loadConfig from './config'
+import loadConfig from "./config"
 import "reflect-metadata"
 import Logger from "./logger"
 import apiLoader from "./api"
+import featureFlagsLoader from "./feature-flags"
 import databaseLoader from "./database"
 import defaultsLoader from "./defaults"
-import expressLoader  from "./express"
+import expressLoader from "./express"
 import modelsLoader from "./models"
 import passportLoader from "./passport"
 import pluginsLoader, { registerPluginModels } from "./plugins"
@@ -18,35 +19,50 @@ import subscribersLoader from "./subscribers"
 import { ClassOrFunctionReturning } from "awilix/lib/container"
 import { Connection, getManager } from "typeorm"
 import { Express, NextFunction, Request, Response } from "express"
-import { asFunction, asValue, AwilixContainer, createContainer, Resolver } from "awilix"
+import {
+  asFunction,
+  asValue,
+  AwilixContainer,
+  createContainer,
+  Resolver,
+} from "awilix"
 import { track } from "medusa-telemetry"
 import { MedusaContainer } from "../types/global"
 
 type Options = {
-  directory: string;
-  expressApp: Express;
+  directory: string
+  expressApp: Express
   isTest: boolean
 }
 
-export default async (
-  {
-    directory: rootDirectory,
-    expressApp,
-    isTest
-  }: Options
-): Promise<{ container: MedusaContainer; dbConnection: Connection; app: Express }> => {
+export default async ({
+  directory: rootDirectory,
+  expressApp,
+  isTest,
+}: Options): Promise<{
+  container: MedusaContainer
+  dbConnection: Connection
+  app: Express
+}> => {
   const configModule = loadConfig(rootDirectory)
 
   const container = createContainer() as MedusaContainer
-  container.register('configModule', asValue(configModule))
+  container.register("configModule", asValue(configModule))
 
-  container.registerAdd = function (this: MedusaContainer, name: string, registration: typeof asFunction | typeof asValue) {
+  container.registerAdd = function (
+    this: MedusaContainer,
+    name: string,
+    registration: typeof asFunction | typeof asValue
+  ) {
     const storeKey = name + "_STORE"
 
     if (this.registrations[storeKey] === undefined) {
       this.register(storeKey, asValue([] as Resolver<unknown>[]))
     }
-    const store = this.resolve(storeKey) as (ClassOrFunctionReturning<unknown> | Resolver<unknown>)[]
+    const store = this.resolve(storeKey) as (
+      | ClassOrFunctionReturning<unknown>
+      | Resolver<unknown>
+    )[]
 
     if (this.registrations[name] === undefined) {
       this.register(name, asArray(store))
@@ -59,15 +75,17 @@ export default async (
   // Add additional information to context of request
   expressApp.use((req: Request, res: Response, next: NextFunction) => {
     const ipAddress = requestIp.getClientIp(req) as string
-
-    (req as any).request_context = {
+    ;(req as any).request_context = {
       ip_address: ipAddress,
     }
     next()
   })
 
+  const featureFlagRouter = featureFlagsLoader(configModule, Logger)
+
   container.register({
-    logger: asValue(Logger)
+    logger: asValue(Logger),
+    featureFlagRouter: asValue(featureFlagRouter),
   })
 
   await redisLoader({ container, configModule, logger: Logger })
@@ -83,7 +101,7 @@ export default async (
   await registerPluginModels({
     rootDirectory,
     container,
-    configModule
+    configModule,
   })
   const pmAct = Logger.success(pmActivity, "Plugin models initialized") || {}
   track("PLUGIN_MODELS_INIT_COMPLETED", { duration: pmAct.duration })
@@ -100,7 +118,7 @@ export default async (
   const dbAct = Logger.success(dbActivity, "Database initialized") || {}
   track("DATABASE_INIT_COMPLETED", { duration: dbAct.duration })
 
-  container.register({ manager: asValue(dbConnection.manager), })
+  container.register({ manager: asValue(dbConnection.manager) })
 
   const stratActivity = Logger.activity("Initializing strategies")
   track("STRATEGIES_INIT_STARTED")
@@ -123,8 +141,8 @@ export default async (
 
   // Add the registered services to the request scope
   expressApp.use((req: Request, res: Response, next: NextFunction) => {
-    container.register({ manager: asValue(getManager()) });
-    (req as any).scope = container.createScope()
+    container.register({ manager: asValue(getManager()) })
+    ;(req as any).scope = container.createScope()
     next()
   })
 

packages/medusa/src/types/feature-flags.ts

@@ -0,0 +1,10 @@
+export interface IFlagRouter {
+  isFeatureEnabled: (key: string) => boolean
+}
+
+export type FlagSettings = {
+  key: string
+  description: string
+  env_key: string
+  default_val: boolean
+}

packages/medusa/src/types/global.ts

@@ -52,6 +52,7 @@ export type ConfigModule = {
     store_cors?: string
     admin_cors?: string
   }
+  featureFlags: Record<string, boolean | string>
   plugins: (
     | {
         resolve: string

packages/medusa/src/utils/db-aware-column.ts

@@ -1,6 +1,6 @@
-import { getConfigFile } from "medusa-core-utils"
-import path from "path"
 import { Column, ColumnOptions, ColumnType } from "typeorm"
+import path from "path"
+import { getConfigFile } from "medusa-core-utils"
 
 const pgSqliteTypeMapping: { [key: string]: ColumnType } = {
   increment: "rowid",

packages/medusa/src/utils/feature-flag-decorators.ts

@@ -0,0 +1,66 @@
+import { getConfigFile } from "medusa-core-utils"
+import { Column, ColumnOptions, Entity, EntityOptions } from "typeorm"
+import featureFlagsLoader from "../loaders/feature-flags"
+import path from "path"
+import { ConfigModule } from "../types/global"
+import { FlagRouter } from "./flag-router"
+
+export function FeatureFlagColumn(
+  featureFlag: string,
+  columnOptions: ColumnOptions
+): PropertyDecorator {
+  const featureFlagRouter = getFeatureFlagRouter()
+
+  if (!featureFlagRouter.isFeatureEnabled(featureFlag)) {
+    return (): void => {
+      // noop
+    }
+  }
+
+  return Column(columnOptions)
+}
+
+export function FeatureFlagDecorators(
+  featureFlag: string,
+  decorators: PropertyDecorator[]
+): PropertyDecorator {
+  const featureFlagRouter = getFeatureFlagRouter()
+
+  if (!featureFlagRouter.isFeatureEnabled(featureFlag)) {
+    return (): void => {
+      // noop
+    }
+  }
+  // eslint-disable-next-line @typescript-eslint/ban-types
+  return (target: Object, propertyKey: string | symbol): void => {
+    decorators.forEach((decorator) => {
+      decorator(target, propertyKey)
+    })
+  }
+}
+
+export function FeatureFlagEntity(
+  featureFlag: string,
+  name?: string,
+  options?: EntityOptions
+): ClassDecorator {
+  // eslint-disable-next-line @typescript-eslint/ban-types
+  return function (target: Function): void {
+    target["isFeatureEnabled"] = function (): boolean {
+      const featureFlagRouter = getFeatureFlagRouter()
+
+      // const featureFlagRouter = featureFlagsLoader(configModule)
+      return featureFlagRouter.isFeatureEnabled(featureFlag)
+    }
+    Entity(name, options)(target)
+  }
+}
+
+function getFeatureFlagRouter(): FlagRouter {
+  const { configModule } = getConfigFile(
+    path.resolve("."),
+    `medusa-config`
+  ) as { configModule: ConfigModule }
+
+  return featureFlagsLoader(configModule)
+}

packages/medusa/src/utils/flag-router.ts

@@ -0,0 +1,17 @@
+import { IFlagRouter } from "../types/feature-flags"
+
+export class FlagRouter implements IFlagRouter {
+  private flags: Record<string, boolean> = {}
+
+  constructor(flags: Record<string, boolean>) {
+    this.flags = flags
+  }
+
+  public isFeatureEnabled(key: string): boolean {
+    return !!this.flags[key]
+  }
+
+  public setFlag(key: string, value = true): void {
+    this.flags[key] = value
+  }
+}