fix(translateText): add termination condition

src/service/translationService.js

@@ -43,6 +43,9 @@ async function translateText(text, fromLanguage, toLanguage) {
 		if (task.output) {
 			return task.output.output
 		}
+		if (task.status === 'STATUS_FAILED' || task.status === 'STATUS_CANCELLED') {
+			throw new Error('Translation task failed')
+		}
 		await new Promise((resolve) => setTimeout(resolve, 2000))
 		const taskResponse = await axios.get(generateOcsUrl(`taskprocessing/task/${task.id}`))
 		return getTaskOutput(taskResponse.data.ocs.data.task)

src/tests/unit/service/translationService.spec.js

@@ -0,0 +1,59 @@
+/**
+ * SPDX-FileCopyrightText: 2026 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+import axios from '@nextcloud/axios'
+import { generateOcsUrl } from '@nextcloud/router'
+import { translateText } from '../../../service/translationService.js'
+
+vi.mock('@nextcloud/axios')
+vi.mock('@nextcloud/router')
+vi.mock('../../../store/mainStore.js', () => ({ default: vi.fn() }))
+
+// Regression test for issue #13156: a translation task that ends in
+// STATUS_FAILED never populates task.output, so getTaskOutput must reject
+// instead of polling taskprocessing/task/{id} forever.
+describe('service/translationService — failed task (issue #13156)', () => {
+	beforeEach(() => {
+		vi.useFakeTimers()
+		generateOcsUrl.mockImplementation((url) => url)
+	})
+	afterEach(() => {
+		vi.clearAllMocks()
+		vi.useRealTimers()
+	})
+
+	it('rejects and stops polling once the task fails', async () => {
+		const runningTask = { id: 42, status: 'STATUS_RUNNING', output: null }
+		const failedTask = { id: 42, status: 'STATUS_FAILED', output: null }
+		axios.post.mockResolvedValue({ data: { ocs: { data: { task: runningTask } } } })
+		axios.get.mockResolvedValue({ data: { ocs: { data: { task: failedTask } } } })
+
+		let rejected = false
+		const settledPromise = translateText('hallo', 'de', 'en').catch(() => {
+			rejected = true
+		})
+
+		await vi.advanceTimersByTimeAsync(2000)
+		await settledPromise
+
+		expect(rejected).toBe(true)
+
+		const callsWhenFailed = axios.get.mock.calls.length
+		await vi.advanceTimersByTimeAsync(10000)
+		expect(axios.get.mock.calls.length).toBe(callsWhenFailed)
+	})
+
+	it('resolves with the translated text once the task succeeds', async () => {
+		const scheduledTask = { id: 7, status: 'STATUS_SCHEDULED', output: null }
+		const doneTask = { id: 7, status: 'STATUS_SUCCESSFUL', output: { output: 'hello' } }
+		axios.post.mockResolvedValue({ data: { ocs: { data: { task: scheduledTask } } } })
+		axios.get.mockResolvedValue({ data: { ocs: { data: { task: doneTask } } } })
+
+		const resultPromise = translateText('hallo', 'de', 'en')
+		await vi.advanceTimersByTimeAsync(2000)
+
+		await expect(resultPromise).resolves.toBe('hello')
+	})
+})