fix(medusa): Allow deleting metadata fields (#3055)

.changeset/three-peaches-move.md

@@ -0,0 +1,5 @@
+---
+"@medusajs/medusa": patch
+---
+
+fix(medusa): Allow users to unset metadata fields in updates.

integration-tests/api/__tests__/admin/product.js

@@ -1334,6 +1334,37 @@ describe("/admin/products", () => {
       expect(response.data.product.images.length).toEqual(0)
     })
 
+    it("updates a product by deleting a field from metadata", async () => {
+      const api = useApi()
+
+      const product = await simpleProductFactory(dbConnection, {
+        metadata: {
+          "test-key": "test-value",
+          "test-key-2": "test-value-2",
+          "test-key-3": "test-value-3",
+        },
+      })
+
+      const payload = {
+        metadata: {
+          "test-key": "",
+          "test-key-2": null,
+        },
+      }
+
+      const response = await api.post(
+        "/admin/products/" + product.id,
+        payload,
+        adminHeaders
+      )
+
+      expect(response.status).toEqual(200)
+      expect(response.data.product.metadata).toEqual({
+        "test-key-2": null,
+        "test-key-3": "test-value-3",
+      })
+    })
+
     it("fails to update product with invalid status", async () => {
       const api = useApi()
 

integration-tests/api/factories/simple-product-factory.ts

@@ -5,17 +5,17 @@ import {
   ProductType,
   ShippingProfile,
   ShippingProfileType,
-  Store
+  Store,
 } from "@medusajs/medusa"
 import faker from "faker"
 import { Connection } from "typeorm"
 import {
   ProductVariantFactoryData,
-  simpleProductVariantFactory
+  simpleProductVariantFactory,
 } from "./simple-product-variant-factory"
 import {
   SalesChannelFactoryData,
-  simpleSalesChannelFactory
+  simpleSalesChannelFactory,
 } from "./simple-sales-channel-factory"
 
 export type ProductFactoryData = {
@@ -28,6 +28,7 @@ export type ProductFactoryData = {
   options?: { id: string; title: string }[]
   variants?: ProductVariantFactoryData[]
   sales_channels?: SalesChannelFactoryData[]
+  metadata?: Record<string, unknown>
 }
 
 export const simpleProductFactory = async (
@@ -83,6 +84,7 @@ export const simpleProductFactory = async (
     discountable: !data.is_giftcard,
     tags: [] as ProductTag[],
     profile_id: data.is_giftcard ? gcProfile?.id : defaultProfile?.id,
+    metadata: data.metadata || null,
   } as Product
 
   if (typeof data.tags !== "undefined") {

packages/medusa/src/utils/set-metadata.ts

@@ -12,6 +12,7 @@ export function setMetadata(
 ): Record<string, unknown> {
   const existing = obj.metadata || {}
   const newData = {}
+
   for (const [key, value] of Object.entries(metadata)) {
     if (typeof key !== "string") {
       throw new MedusaError(
@@ -19,6 +20,21 @@ export function setMetadata(
         "Key type is invalid. Metadata keys must be strings"
       )
     }
+
+    /**
+     * We reserve the empty string as a way to delete a key.
+     * If the value is an empty string, we don't
+     * set it, and if it exists in the existing metadata, we
+     * unset the field.
+     */
+    if (value === "") {
+      if (key in existing) {
+        delete existing[key]
+      }
+
+      continue
+    }
+
     newData[key] = value
   }