fix: delete region causes cascade error (#672)

Co-authored-by: olivermrbl <oliver@mrbltech.com>

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

@@ -0,0 +1,73 @@
+const path = require("path")
+const { Region, FulfillmentProvider } = require("@medusajs/medusa")
+
+const setupServer = require("../../../helpers/setup-server")
+const { useApi } = require("../../../helpers/use-api")
+const { initDb, useDb } = require("../../../helpers/use-db")
+const adminSeeder = require("../../helpers/admin-seeder")
+
+jest.setTimeout(30000)
+
+describe("/admin/discounts", () => {
+  let medusaProcess
+  let dbConnection
+
+  beforeAll(async () => {
+    const cwd = path.resolve(path.join(__dirname, "..", ".."))
+    dbConnection = await initDb({ cwd })
+    medusaProcess = await setupServer({ cwd, verbose: true })
+  })
+
+  afterAll(async () => {
+    const db = useDb()
+    await db.shutdown()
+    medusaProcess.kill()
+  })
+
+  describe("DELETE /admin/regions/:id", () => {
+    beforeEach(async () => {
+      const manager = dbConnection.manager
+      await adminSeeder(dbConnection)
+      await manager.insert(Region, {
+        id: "test-region",
+        name: "Test Region",
+        currency_code: "usd",
+        tax_rate: 0,
+      })
+    })
+
+    afterEach(async () => {
+      const db = useDb()
+      await db.teardown()
+    })
+
+    it("successfully deletes a region with a fulfillment provider", async () => {
+      const api = useApi()
+
+      // add fulfillment provider to the region
+      await api.post(
+        "/admin/regions/test-region",
+        {
+          fulfillment_providers: ["test-ful"],
+        },
+        {
+          headers: {
+            Authorization: "Bearer test_token",
+          },
+        }
+      )
+
+      const response = await api
+        .delete(`/admin/regions/test-region`, {
+          headers: {
+            Authorization: "Bearer test_token",
+          },
+        })
+        .catch((err) => {
+          console.log(err)
+        })
+
+      expect(response.status).toEqual(200)
+    })
+  })
+})