Replace JSXElement node on 'exit' instead of 'enter'.

[nandin-borjigin]

Current behavior of this plugin is replacing the entire JSXElement node, along with its children, on enter phase, which hinders other plugins from visiting decendants of that JSXElement recursively.

Usecase:

Suppose that a plugin foo is to collect thrid party component references in every file and then emit a file that imports and globally registeres all used components (common practice when the third party library provides tons of components but only a few of them is of interest).

Problem:

With this (referring to @vue/babel-plugin-transform-vue-jsx) plugin applied, foo can only visit the root JSXElement and all of its children would not be visited because they would have been replaced with normal h call by this plugin. Indeed, author of foo can traverse the children of root JSXElement by himself/herself but that would be duplicating the visitor pattern provided by babel.

Solution:

Changing this plugin's visitor to replace the original jsx node on exit phase would make other plugins (which are, by assumption, applied prior to this plugin) have a chance to recursively visit all the jsx nodes, without affecting the original behavior of this plugin.

Reference:

Both babel-plugin-jsx and babel-plugin-transform-react-jsx(which inherits the former) are applying the actual transformation on exit phase.