kv, err := libkvmock.New([]string{}, nil)

assert.NoError(t, err)

assert.NotNil(t, kv)

mockStore := kv.(*libkvmock.Mock)

kvCh := make(chan *store.KVPair)

var mockKVCh <-chan *store.KVPair = kvCh

mockStore.On("Watch", "test_key", mock.Anything).Return(mockKVCh, nil)

follower := NewFollower(kv, "test_key")

leaderCh, errCh := follower.FollowElection()

// Simulate leader updates

go func() {

kvCh <- &store.KVPair{Key: "test_key", Value: []byte("leader1")}

kvCh <- &store.KVPair{Key: "test_key", Value: []byte("leader1")}

kvCh <- &store.KVPair{Key: "test_key", Value: []byte("leader2")}

kvCh <- &store.KVPair{Key: "test_key", Value: []byte("leader1")}

}()

// We shouldn't see duplicate events.

assert.Equal(t, <-leaderCh, "leader1")

assert.Equal(t, <-leaderCh, "leader2")

assert.Equal(t, <-leaderCh, "leader1")

assert.Equal(t, follower.Leader(), "leader1")

// Once stopped, iteration over the leader channel should stop.

follower.Stop()

close(kvCh)

// Assert that we receive an error from the error chan to deal with the failover

err, open := <-errCh

assert.True(t, open)

assert.NotNil(t, err)

// Ensure that the chan is closed

_, open = <-leaderCh

assert.False(t, open)

mockStore.AssertExpectations(t)