feat(admin-bundler,admin-vite-plugin,medusa): Add support for loading Admin Extensions from plugins (#10869)

Should not be merged before https://github.com/medusajs/medusa/pull/10895

**What**
- Introduces a new `plugin` command to `admin-bundler`, currently not used anywhere but will be called from `medusa build:plugin`
- Discovers plugins with extensions and add passes the to `admin-vite-plugin`.
- Updates `admin-vite-plugin` so its able to read built admin extensions.

Resolves CMRC-830, CMRC-839

packages/medusa/src/loaders/admin.ts

@@ -1,5 +1,9 @@
 import { logger } from "@medusajs/framework/logger"
-import { AdminOptions, ConfigModule } from "@medusajs/framework/types"
+import {
+  AdminOptions,
+  ConfigModule,
+  PluginDetails,
+} from "@medusajs/framework/types"
 import { Express } from "express"
 import fs from "fs"
 import path from "path"
@@ -9,6 +13,7 @@ type Options = {
   app: Express
   configModule: ConfigModule
   rootDirectory: string
+  plugins: PluginDetails[]
 }
 
 type IntializedOptions = Required<Pick<AdminOptions, "path" | "disable">> &
@@ -23,16 +28,18 @@ export default async function adminLoader({
   app,
   configModule,
   rootDirectory,
+  plugins,
 }: Options) {
   const { admin } = configModule
 
   const sources: string[] = []
 
-  const projectSource = path.join(rootDirectory, "src", "admin")
+  for (const plugin of plugins) {
+    const pluginSource = path.join(plugin.resolve, "admin")
 
-  // check if the projectSource exists
-  if (fs.existsSync(projectSource)) {
-    sources.push(projectSource)
+    if (fs.existsSync(pluginSource)) {
+      sources.push(pluginSource)
+    }
   }
 
   const adminOptions: IntializedOptions = {

packages/medusa/src/loaders/index.ts

@@ -1,3 +1,12 @@
+import { container, MedusaAppLoader } from "@medusajs/framework"
+import { configLoader } from "@medusajs/framework/config"
+import { pgConnectionLoader } from "@medusajs/framework/database"
+import { featureFlagsLoader } from "@medusajs/framework/feature-flags"
+import { expressLoader } from "@medusajs/framework/http"
+import { JobLoader } from "@medusajs/framework/jobs"
+import { LinkLoader } from "@medusajs/framework/links"
+import { logger } from "@medusajs/framework/logger"
+import { SubscriberLoader } from "@medusajs/framework/subscribers"
 import {
   ConfigModule,
   LoadedModule,
@@ -10,6 +19,7 @@ import {
   mergePluginModules,
   promiseAll,
 } from "@medusajs/framework/utils"
+import { WorkflowLoader } from "@medusajs/framework/workflows"
 import { asValue } from "awilix"
 import { Express, NextFunction, Request, Response } from "express"
 import { join } from "path"
@@ -17,16 +27,6 @@ import requestIp from "request-ip"
 import { v4 } from "uuid"
 import adminLoader from "./admin"
 import apiLoader from "./api"
-import { configLoader } from "@medusajs/framework/config"
-import { expressLoader } from "@medusajs/framework/http"
-import { JobLoader } from "@medusajs/framework/jobs"
-import { LinkLoader } from "@medusajs/framework/links"
-import { logger } from "@medusajs/framework/logger"
-import { container, MedusaAppLoader } from "@medusajs/framework"
-import { pgConnectionLoader } from "@medusajs/framework/database"
-import { SubscriberLoader } from "@medusajs/framework/subscribers"
-import { WorkflowLoader } from "@medusajs/framework/workflows"
-import { featureFlagsLoader } from "@medusajs/framework/feature-flags"
 import { getResolvedPlugins } from "./helpers/resolve-plugins"
 
 type Options = {
@@ -107,7 +107,7 @@ async function loadEntrypoints(
     next()
   })
 
-  await adminLoader({ app: expressApp, configModule, rootDirectory })
+  await adminLoader({ app: expressApp, configModule, rootDirectory, plugins })
   await apiLoader({
     container,
     plugins,