MM-48447 - Calls: guard against possible bad response from server (null) (#6769)

* guard against possible bad response from server (null)

* lock it down with a test

app/products/calls/actions/calls.test.ts

@@ -268,6 +268,36 @@ describe('Actions.Calls', () => {
         assert.equal((result.current[2] as CurrentCall | null), null);
     });
 
+    it('loadCalls fails from server', async () => {
+        const expectedCallsState: CallsState = {
+            serverUrl: 'server1',
+            myUserId: 'userId1',
+            calls: {},
+            enabled: {},
+        };
+
+        // setup
+        const oldGetCalls = mockClient.getCalls;
+
+        // eslint-disable-next-line @typescript-eslint/ban-ts-comment
+        // @ts-ignore
+        mockClient.getCalls = jest.fn(() => null);
+
+        const {result} = renderHook(() => {
+            return [useCallsState('server1'), useChannelsWithCalls('server1'), useCurrentCall()];
+        });
+
+        await act(async () => {
+            await CallsActions.loadCalls('server1', 'userId1');
+        });
+        expect(mockClient.getCalls).toBeCalled();
+        assert.deepEqual((result.current[0] as CallsState), expectedCallsState);
+        assert.deepEqual((result.current[1] as ChannelsWithCalls), {});
+        assert.equal((result.current[2] as CurrentCall | null), null);
+
+        mockClient.getCalls = oldGetCalls;
+    });
+
     it('loadConfig', async () => {
         // setup
         const {result} = renderHook(() => useCallsConfig('server1'));

app/products/calls/actions/calls.ts

@@ -86,7 +86,7 @@ export const loadCalls = async (serverUrl: string, userId: string) => {
     }
     let resp: ServerChannelState[] = [];
     try {
-        resp = await client.getCalls();
+        resp = await client.getCalls() || [];
     } catch (error) {
         await forceLogoutIfNecessary(serverUrl, error as ClientError);
         return {error};