Why add the function name to the function expression

Look at some source framework (uncompressed) when occasionally see them give expression to add function function name.
For example, the following code:

// 添加函数名
setTimeout(function foo() {
  console.log('foo');
}, 1000);

// 不给函数表达式看起来更简洁
setTimeout(function () {
  console.log('foo');
}, 1000);

In fact, the function name is added to the function expression is a best practice, there are several reasons below:

1, if the code error function name can quickly locate the error location, otherwise anonymous function 栈追踪does not show a meaningful function names, difficult to debug.

2, no function name, the function would like to quote their own need to rely on already obsolete arguments.callee. There is a classic example of this is the use of removeEventListener()required unbundling event function, that is, itself.

3, function names can improve the readability \ understandability of code, a bunch of anonymous functions makes the code becomes confusing.