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

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
   }