feat(medusa): List (service + controller) product categories #3004 (#3023)

**What:**

Introduces a store endpoint to retrieve a list of product categories

**Why:**

This is part of a greater goal of allowing products to be added to multiple categories.

**How:**

- Creates an endpoint in store routes

RESOLVES CORE-968

packages/medusa/src/api/routes/admin/product-categories/list-product-categories.ts

@@ -18,6 +18,8 @@ import { extendedFindParamsMixin } from "../../../../types/common"
  *   - (query) parent_category_id {string} Returns categories scoped by parent
  *   - (query) offset=0 {integer} How many product categories to skip in the result.
  *   - (query) limit=100 {integer} Limit the number of product categories returned.
+ *   - (query) expand {string} (Comma separated) Which fields should be expanded in the product category.
+ *   - (query) fields {string} (Comma separated) Which fields should be included in the product category.
  * x-codeSamples:
  *   - lang: Shell
  *     label: cURL

packages/medusa/src/api/routes/store/product-categories/index.ts

@@ -4,11 +4,26 @@ import getProductCategory, {
   StoreGetProductCategoryParams,
 } from "./get-product-category"
 
+import listProductCategories, {
+  StoreGetProductCategoriesParams,
+} from "./list-product-categories"
+
 const route = Router()
 
 export default (app) => {
   app.use("/product-categories", route)
 
+  route.get(
+    "/",
+    transformQuery(StoreGetProductCategoriesParams, {
+      defaultFields: defaultStoreProductCategoryFields,
+      allowedFields: allowedStoreProductCategoryFields,
+      defaultRelations: defaultStoreProductCategoryRelations,
+      isList: true,
+    }),
+    middlewares.wrap(listProductCategories)
+  )
+
   route.get(
     "/:id",
     transformQuery(StoreGetProductCategoryParams, {
@@ -37,6 +52,7 @@ export const defaultStoreProductCategoryFields = [
   "id",
   "name",
   "handle",
+  "parent_category_id",
   "created_at",
   "updated_at",
 ]
@@ -45,8 +61,10 @@ export const allowedStoreProductCategoryFields = [
   "id",
   "name",
   "handle",
+  "parent_category_id",
   "created_at",
   "updated_at",
 ]
 
 export * from "./get-product-category"
+export * from "./list-product-categories"

packages/medusa/src/api/routes/store/product-categories/list-product-categories.ts

@@ -0,0 +1,102 @@
+import { IsNumber, IsOptional, IsString } from "class-validator"
+import { Request, Response } from "express"
+import { Type, Transform } from "class-transformer"
+
+import { ProductCategoryService } from "../../../../services"
+import { extendedFindParamsMixin } from "../../../../types/common"
+import { defaultStoreScope } from "."
+
+/**
+ * @oas [get] /product-categories
+ * operationId: "GetProductCategories"
+ * summary: "List Product Categories"
+ * description: "Retrieve a list of product categories."
+ * x-authenticated: false
+ * parameters:
+ *   - (query) q {string} Query used for searching product category names orhandles.
+ *   - (query) parent_category_id {string} Returns categories scoped by parent
+ *   - (query) offset=0 {integer} How many product categories to skip in the result.
+ *   - (query) limit=100 {integer} Limit the number of product categories returned.
+ * x-codeSamples:
+ *   - lang: Shell
+ *     label: cURL
+ *     source: |
+ *       curl --location --request GET 'https://medusa-url.com/store/product-categories' \
+ *       --header 'Authorization: Bearer {api_token}'
+ * security:
+ *   - api_token: []
+ *   - cookie_auth: []
+ * tags:
+ *   - Product Category
+ * responses:
+ *   200:
+ *     description: OK
+ *     content:
+ *       application/json:
+ *         schema:
+ *           type: object
+ *           properties:
+ *             product_categories:
+ *               type: array
+ *               items:
+ *                 $ref: "#/components/schemas/ProductCategory"
+ *             count:
+ *               type: integer
+ *               description: The total number of items available
+ *             offset:
+ *               type: integer
+ *               description: The number of items skipped before these items
+ *             limit:
+ *               type: integer
+ *               description: The number of items per page
+ *   "400":
+ *     $ref: "#/components/responses/400_error"
+ *   "401":
+ *     $ref: "#/components/responses/unauthorized"
+ *   "404":
+ *     $ref: "#/components/responses/not_found_error"
+ *   "409":
+ *     $ref: "#/components/responses/invalid_state_error"
+ *   "422":
+ *     $ref: "#/components/responses/invalid_request_error"
+ *   "500":
+ *     $ref: "#/components/responses/500_error"
+ */
+export default async (req: Request, res: Response) => {
+  const productCategoryService: ProductCategoryService = req.scope.resolve(
+    "productCategoryService"
+  )
+
+  const selectors = Object.assign({ ...defaultStoreScope }, req.filterableFields)
+
+  const [data, count] = await productCategoryService.listAndCount(
+    selectors,
+    req.listConfig,
+    defaultStoreScope
+  )
+
+  const { limit, offset } = req.validatedQuery
+
+  res.json({
+    count,
+    offset,
+    limit,
+    product_categories: data,
+  })
+}
+
+export class StoreGetProductCategoriesParams extends extendedFindParamsMixin({
+  limit: 100,
+  offset: 0,
+}) {
+  @IsString()
+  @IsOptional()
+  q?: string
+
+  @IsString()
+  @IsOptional()
+  @Transform(({ value }) => {
+    return value === "null" ? null : value
+  })
+  parent_category_id?: string | null
+}