huacnlee/ruby-china — comment on commit 194fe73c9a2fc9fe21a9960fada9f1b7df1be039
File: spec/models/topic_spec.rb line 17
By cqpx:

include可以用这个

```
topic.follower_ids.should include(user.id)
topic.follower_ids.should_not include(user.id)
```
两者的区别在于出错信息不同：

```
Failure/Error: topic.follower_ids.include?(user.id).should be_false
expected true to be false
```

```
Failure/Error: topic.follower_ids.should_not include(user.id)
expected [2] not to include 2
```