feat; add factory method for extensions (#7218)

.changeset/gentle-lies-provide.md

@@ -0,0 +1,28 @@
+---
+"@vue-storefront/middleware": minor
+---
+
+[ADDED] Added factory function for the extension API. Previously the extension API was an object with a set of methods. Now it can be created using a factory function the same way as the base API.
+
+Previously only object was allowed:
+
+```ts
+export const extension: ApiClientExtension = {
+  name: "extension",
+  extendApiMethods: {
+    ...extendedMethods, //methods as an object
+  },
+};
+```
+
+Now you can either use an object or a factory function:
+
+```ts
+export const extension: ApiClientExtension = {
+  name: "extension",
+  // methods as a factory function with injected config object
+  extendApiMethods: ({ config }) => {
+    return createMyMethods(config);
+  },
+};
+```

packages/middleware/src/apiClientFactory/index.ts

@@ -1,3 +1,4 @@
+import { isFunction } from "../helpers";
 import {
   ApiClientConfig,
   ApiClientExtension,
@@ -10,7 +11,6 @@ import {
   ExtensionHookWith,
   ExtensionWith,
 } from "../types";
-import { isFunction } from "../helpers";
 import { applyContextToApi } from "./applyContextToApi";
 
 const apiClientFactory = <
@@ -19,6 +19,14 @@ const apiClientFactory = <
 >(
   factoryParams: ApiClientFactoryParams<ALL_SETTINGS, ALL_FUNCTIONS>
 ): ApiClientFactory<any, ALL_FUNCTIONS> => {
+  const resolveApi = async (api: any, settings: any) => {
+    if (typeof api === "function") {
+      return await api(settings);
+    }
+
+    return api ?? {};
+  };
+
   const createApiClient: CreateApiClientFn<any, ALL_FUNCTIONS> =
     async function createApiClient(
       this: CallableContext<ALL_FUNCTIONS>,
@@ -97,29 +105,28 @@ const apiClientFactory = <
 
       const context = { ...settings, ...(this?.middleware || {}) };
 
-      const { api: apiOrApiFactory = {} } = factoryParams;
-
-      const isApiFactory = typeof apiOrApiFactory === "function";
-      const api = isApiFactory
-        ? await apiOrApiFactory(settings)
-        : apiOrApiFactory;
+      const api = await resolveApi(factoryParams.api, settings);
 
       const namespacedExtensions: Record<string, any> = {};
       let sharedExtensions = customApi;
 
-      rawExtensions.forEach((extension) => {
+      for await (const extension of rawExtensions) {
+        const extendedApiMethods = await resolveApi(
+          extension.extendApiMethods,
+          settings
+        );
         if (extension.isNamespaced) {
           namespacedExtensions[extension.name] = {
             ...(namespacedExtensions?.[extension.name] ?? {}),
-            ...extension.extendApiMethods,
+            ...extendedApiMethods,
           };
         } else {
           sharedExtensions = {
             ...sharedExtensions,
-            ...extension.extendApiMethods,
+            ...extendedApiMethods,
           };
         }
-      });
+      }
 
       const integrationApi = applyContextToApi(
         api,

packages/middleware/src/types/common.ts

@@ -1,19 +1,19 @@
 import type { Express, Request, Response } from "express";
-import { WithRequired } from "./index";
 import {
   ApiClientMethod,
   ContextQuery,
   CustomQuery,
   CustomQueryFunction,
   TObject,
 } from "./base";
+import { WithRequired } from "./index";
 import { ApiClient, ApiClientConfig, ApiClientFactory } from "./server";
 
 export type ApiMethods = Record<string, ApiClientMethod>;
 export type ApiMethodsFactory<
   API extends ApiMethods,
   CONFIG extends ApiClientConfig
-> = (configuration: CONFIG) => API;
+> = (configuration: { config: CONFIG }) => API;
 
 export type ApiClientMethodWithContext<CONTEXT> = (
   context: CONTEXT,
@@ -55,10 +55,12 @@ export interface ApiClientExtensionHooks<C = any> {
   ) => AfterCallArgs;
 }
 
-export interface ApiClientExtension<API = any, CONTEXT = any> {
+export interface ApiClientExtension<API = any, CONTEXT = any, CONFIG = any> {
   name: string;
   isNamespaced?: boolean;
-  extendApiMethods?: ExtendApiMethod<API, CONTEXT>;
+  extendApiMethods?:
+    | ExtendApiMethod<API, CONTEXT>
+    | ApiMethodsFactory<ExtendApiMethod<API, CONTEXT>, CONFIG>;
   extendApp?: ({
     app,
     configuration,