Persist traffic settings and support multi-device traffic views

test/server/live-traffic-route.test.js

@@ -206,3 +206,48 @@ test('route is unavailable when no traffic collector exists', async () => {
     (error) => error.code === 'ENDPOINT_NOT_FOUND',
   );
 });
+
+test('PUT persists validated traffic settings with revision protection and returns canonical state', async () => {
+  let state = { revision: 4, traffic: { grouping: 'site', sort: 'popular', retentionSeconds: 10 } };
+  let sent = false;
+  const route = createLiveTrafficRoute({
+    traffic: null,
+    settingsState: {
+      read: () => state,
+      update: (mutator) => { state = { ...mutator(state), revision: state.revision + 1 }; },
+    },
+    readBody: async () => ({
+      settings: { grouping: 'device', sort: 'recent', retentionSeconds: 30 },
+      expectedRevision: 4,
+    }),
+    sendState: async (res) => { sent = true; res.end(JSON.stringify(state)); },
+  });
+  const res = response();
+
+  assert.equal(await route.handle({ method: 'PUT', url: '/api/traffic/settings' }, res), true);
+  assert.equal(sent, true);
+  assert.deepEqual(state.traffic, { grouping: 'device', sort: 'recent', retentionSeconds: 30 });
+  assert.equal(state.revision, 5);
+
+  const conflict = createLiveTrafficRoute({
+    traffic: null,
+    settingsState: { read: () => state, update: () => { throw new Error('must not update'); } },
+    readBody: async () => ({ settings: state.traffic, expectedRevision: 4 }),
+    sendState: async () => {},
+  });
+  await assert.rejects(
+    conflict.handle({ method: 'PUT', url: '/api/traffic/settings' }, response()),
+    (error) => error.code === 'STATE_CONFLICT',
+  );
+
+  const invalid = createLiveTrafficRoute({
+    traffic: null,
+    settingsState: { read: () => state, update: () => { throw new Error('must not update'); } },
+    readBody: async () => ({ settings: { grouping: 'guess' }, expectedRevision: 5 }),
+    sendState: async () => {},
+  });
+  await assert.rejects(
+    invalid.handle({ method: 'PUT', url: '/api/traffic/settings' }, response()),
+    (error) => error.code === 'REQUEST_INVALID',
+  );
+});