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

integration-tests/api/__tests__/store/product-category.ts

@@ -34,39 +34,42 @@ describe("/store/product-categories", () => {
     medusaProcess.kill()
   })
 
-  describe("GET /store/product-categories/:id", () => {
-    beforeEach(async () => {
-      productCategoryParent = await simpleProductCategoryFactory(dbConnection, {
-        name: "category parent",
-        is_active: true,
-      })
-
-      productCategory = await simpleProductCategoryFactory(dbConnection, {
-        name: "category",
-        parent_category: productCategoryParent,
-        is_active: true,
-      })
-
-      productCategoryChild = await simpleProductCategoryFactory(dbConnection, {
-        name: "category child",
-        parent_category: productCategory,
-        is_active: true,
-      })
-
-      productCategoryChild2 = await simpleProductCategoryFactory(dbConnection, {
-        name: "category child 2",
-        parent_category: productCategory,
-        is_internal: true,
-        is_active: true,
-      })
-
-      productCategoryChild3 = await simpleProductCategoryFactory(dbConnection, {
-        name: "category child 3",
-        parent_category: productCategory,
-        is_active: false,
-      })
+  beforeEach(async () => {
+    productCategoryParent = await simpleProductCategoryFactory(dbConnection, {
+      name: "category parent",
+      is_active: true,
+      is_internal: false,
     })
 
+    productCategory = await simpleProductCategoryFactory(dbConnection, {
+      name: "category",
+      parent_category: productCategoryParent,
+      is_active: true,
+    })
+
+    productCategoryChild = await simpleProductCategoryFactory(dbConnection, {
+      name: "category child",
+      parent_category: productCategory,
+      is_active: true,
+      is_internal: false,
+    })
+
+    productCategoryChild2 = await simpleProductCategoryFactory(dbConnection, {
+      name: "category child 2",
+      parent_category: productCategory,
+      is_internal: true,
+      is_active: true,
+    })
+
+    productCategoryChild3 = await simpleProductCategoryFactory(dbConnection, {
+      name: "category child 3",
+      parent_category: productCategory,
+      is_active: false,
+      is_internal: false,
+    })
+  })
+
+  describe("GET /store/product-categories/:id", () => {
     afterEach(async () => {
       const db = useDb()
       return await db.teardown()
@@ -142,4 +145,109 @@ describe("/store/product-categories", () => {
       )
     })
   })
+
+  describe("GET /store/product-categories", () => {
+    afterEach(async () => {
+      const db = useDb()
+      return await db.teardown()
+    })
+
+    it("gets list of product category with immediate children and parents", async () => {
+      const api = useApi()
+
+      const response = await api.get(
+        `/store/product-categories`,
+      )
+
+      expect(response.status).toEqual(200)
+      expect(response.data.count).toEqual(3)
+      expect(response.data.offset).toEqual(0)
+      expect(response.data.limit).toEqual(100)
+      expect(response.data.product_categories).toEqual(
+        expect.arrayContaining([
+          expect.objectContaining({
+            id: productCategoryParent.id,
+            parent_category: null,
+            category_children: [
+              expect.objectContaining({
+                id: productCategory.id,
+              })
+            ],
+          }),
+          expect.objectContaining({
+            id: productCategory.id,
+            parent_category: expect.objectContaining({
+              id: productCategoryParent.id,
+            }),
+            category_children: [
+              expect.objectContaining({
+                id: productCategoryChild.id,
+              }),
+            ],
+          }),
+          expect.objectContaining({
+            id: productCategoryChild.id,
+            parent_category: expect.objectContaining({
+              id: productCategory.id,
+            }),
+            category_children: [],
+          }),
+        ])
+      )
+    })
+
+    it("throws error when querying not allowed fields", async () => {
+      const api = useApi()
+
+      const error = await api.get(
+        `/store/product-categories?is_internal=true`,
+      ).catch(e => e)
+
+      expect(error.response.status).toEqual(400)
+      expect(error.response.data.type).toEqual('invalid_data')
+      expect(error.response.data.message).toEqual('property is_internal should not exist')
+    })
+
+    it("filters based on free text on name and handle columns", async () => {
+      const api = useApi()
+
+      const response = await api.get(
+        `/store/product-categories?q=category-parent`,
+      )
+
+      expect(response.status).toEqual(200)
+      expect(response.data.count).toEqual(1)
+      expect(response.data.product_categories[0].id).toEqual(productCategoryParent.id)
+    })
+
+    it("filters based on parent category", async () => {
+      const api = useApi()
+
+      const response = await api.get(
+        `/store/product-categories?parent_category_id=${productCategory.id}`,
+      )
+
+      expect(response.status).toEqual(200)
+      expect(response.data.count).toEqual(1)
+      expect(response.data.product_categories).toEqual(
+        expect.arrayContaining([
+          expect.objectContaining({
+            id: productCategoryChild.id,
+            category_children: [],
+            parent_category: expect.objectContaining({
+              id: productCategory.id,
+            }),
+          }),
+        ])
+      )
+
+      const nullCategoryResponse = await api.get(
+        `/store/product-categories?parent_category_id=null`,
+      ).catch(e => e)
+
+      expect(nullCategoryResponse.status).toEqual(200)
+      expect(nullCategoryResponse.data.count).toEqual(1)
+      expect(nullCategoryResponse.data.product_categories[0].id).toEqual(productCategoryParent.id)
+    })
+  })
 })