diff --git a/Sense/ui/tests/devicePayload.test.mjs b/Sense/ui/tests/devicePayload.test.mjs
new file mode 100644
index 0000000..9c8c2eb
--- /dev/null
+++ b/Sense/ui/tests/devicePayload.test.mjs
@@ -0,0 +1,34 @@
+import assert from 'node:assert/strict'
+import test from 'node:test'
+
+import { createDevicePayload, updateDevicePayload } from '../src/views/sense/device/devicePayload.mjs'
+
+const form = {
+  name: '东门摄像机',
+  location: '教学楼一楼东门',
+  modality: 'video',
+  capabilities: ['video'],
+  id: 'read-only-id'
+}
+
+test('create payload keeps Chinese values and includes modality', () => {
+  assert.deepEqual(createDevicePayload(form), {
+    name: '东门摄像机',
+    location: '教学楼一楼东门',
+    modality: 'video',
+    capabilities: ['video']
+  })
+})
+
+test('update payload uses the PATCH allowlist and excludes modality', () => {
+  const payload = updateDevicePayload(form, 9)
+  assert.deepEqual(payload, {
+    name: '东门摄像机',
+    location: '教学楼一楼东门',
+    capabilities: ['video'],
+    version: 9
+  })
+  assert.equal('modality' in payload, false)
+  assert.equal('id' in payload, false)
+})
+