为什么我不应该在React Redux中使用toJS（）？ （mapStateToProps）

Question

I've just read it on Redux's docs, that I shouldn't really use Immutable with Redux. I just can't my head around this thing. Why I shouldn't use toJS() in the mapStateToProps? I mean React is using Deep Compare, AND I didn't had any re-render problem with it yet. (I just logging on render to see if is there any leak.)

Answer 1

Why I shouldn't use toJS() in the mapStateToProps

You shouldn't use toJS() in mapStateToProps because toJS() returns a new object reference and even though connect is pure(ie it does shallow comparison), it may so happen that its returns a false negative when the object is nested and in this case your component will re-render ie the render function will be called and react will have to run the diffing algorithm which will have a performance impact as the size of your App goes.