note.md

note

首次尝试写react组件，在搭建过程遇见一些坑，不理解的概念，就此记录📝一下。

##peerDependencies

In some cases, you want to express the compatibility of your package with a host tool or library, while not necessarily doing a require of this host. This is usually referred to as a plugin. Notably, your module may be exposing a specific interface, expected and specified by the host documentation.

大概的意思就是：通常是在插件开发的场景下，你的插件需要某些依赖的支持，但是你又没必要去安装，因为插件的宿主会去安装这些依赖，你就可以用peerDependencies去声明一下需要依赖的插件和版本，如果出问题npm就会有警告来提醒使用者去解决版本冲突问题。

what's the difference between setupFiles and setupTestFrameworkScriptFile of jest ？

参考：https://stackoverflow.com/questions/47587689/whats-the-difference-between-setupfiles-and-setuptestframeworkscriptfile?rq=1

setupTestFrameworkScriptFile and setupFiles are executed before each file containing tests. If you have 10 tests in one file - no mater how many describe's - it will run once. If in 2 separate files - it will run twice.

In both setupTestFrameworkScriptFile and setupFiles you can initiate globals, like this: global.MY_GLOBAL = 42

setupFiles run before test framework is installed in the environment.

In setupTestFrameworkScriptFile you have also access to installed test environment, methods like describe, expect and other globals. You can for example add your custom matchers there: