From 8f63a1befc46ab2ef1a9353b16d7d5689a33cddf Mon Sep 17 00:00:00 2001
From: Prios Shrestha <30313649+priosshrsth@users.noreply.github.com>
Date: Fri, 7 Aug 2026 10:33:34 +0545
Subject: [PATCH] OUT-4027 | Fix 500 when deleting a task whose label row is
 missing (#1397)

deleteLabel passed `id: currentLabel?.id` straight into label.delete, so when
findFirst matched nothing Prisma got `{ id: undefined }` and threw
PrismaClientValidationError, failing the whole delete transaction. Return early
instead.
---
 .../label-mapping.service.test.ts             | 44 +++++++++++++++++++
 .../label-mapping/label-mapping.service.ts    |  3 +-
 2 files changed, 46 insertions(+), 1 deletion(-)
 create mode 100644 src/app/api/label-mapping/label-mapping.service.test.ts

diff --git a/src/app/api/label-mapping/label-mapping.service.test.ts b/src/app/api/label-mapping/label-mapping.service.test.ts
new file mode 100644
index 000000000..24a195ede
--- /dev/null
+++ b/src/app/api/label-mapping/label-mapping.service.test.ts
@@ -0,0 +1,44 @@
+const mockLabelFindFirst = jest.fn()
+const mockLabelDelete = jest.fn()
+
+jest.mock('@/lib/db', () => ({
+  __esModule: true,
+  default: {
+    getInstance: () => ({
+      label: { findFirst: mockLabelFindFirst, delete: mockLabelDelete },
+    }),
+  },
+}))
+
+jest.mock('@/utils/CopilotAPI', () => ({ CopilotAPI: jest.fn() }))
+
+import { LabelMappingService } from '@api/label-mapping/label-mapping.service'
+import User from '@api/core/models/User.model'
+import { UserRole } from '@api/core/types/user'
+
+const user = {
+  workspaceId: 'ws-1',
+  role: UserRole.IU,
+  internalUserId: 'iu-1',
+  token: 'token',
+} as unknown as User
+
+describe('LabelMappingService#deleteLabel', () => {
+  beforeEach(() => jest.clearAllMocks())
+
+  it('deletes the matching label row', async () => {
+    mockLabelFindFirst.mockResolvedValue({ id: 'label-1' })
+
+    await new LabelMappingService(user).deleteLabel('ASS10-009')
+
+    expect(mockLabelDelete).toHaveBeenCalledWith({ where: { id: 'label-1' } })
+  })
+
+  it('no-ops when the label row is already gone', async () => {
+    mockLabelFindFirst.mockResolvedValue(null)
+
+    await new LabelMappingService(user).deleteLabel('ASS10-009')
+
+    expect(mockLabelDelete).not.toHaveBeenCalled()
+  })
+})
diff --git a/src/app/api/label-mapping/label-mapping.service.ts b/src/app/api/label-mapping/label-mapping.service.ts
index 42007a03c..b0d9c2abd 100644
--- a/src/app/api/label-mapping/label-mapping.service.ts
+++ b/src/app/api/label-mapping/label-mapping.service.ts
@@ -175,9 +175,10 @@ export class LabelMappingService extends BaseService {
         label,
       },
     })
+    if (!currentLabel) return
     await this.db.label.delete({
       where: {
-        id: currentLabel?.id,
+        id: currentLabel.id,
       },
     })
   }