lodash - Lodash链功能的调试

Question

如何在浏览器中调试lodash链函数。

例如:

if (_.size(_.values(_.omit(this.user, 'language')).filter(Boolean)) < 2)

如果我们想调试_.omit(this.user, 'language')，然后使用另一个函数_.values()来调试最终结果，如下所示举个例子，应该做什么。

我尝试搜索，但只能找到 console.log，但如果我们想直接在浏览器中调试，我们该怎么做。

Answer 1

链函数和 lodash 序列通常通过 _.tap 进行“调试”或“利用”或_.thru :

tap: This method invokes interceptor and returns value. The interceptor is invoked with one argument; (value). The purpose of this method is to "tap into" a method chain sequence in order to modify intermediate results.

所以像这样:

const obj = { name: 'Ace', language: 'English', age: 3 }

const result = _(obj)
 .tap(x => console.log(x))
 .omit('language')
 .tap(x => console.log(x))
 .omit('age')
 .tap(x=> console.log(x))
 .value()

<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.10/lodash.min.js"></script>

thru: This method is like _.tap except that it returns the result of interceptor. The purpose of this method is to "pass thru" values replacing intermediate results in a method chain sequence.