intellij 打开node项目 一直停留在scanning files to index....，或跳出内存不够的提示框
说明：
在npm install 后，会出现Scanning files to index ...... 出现这个是正常的，但是一直不消失就不正常了。原因是npm install 后 node_modules 内增加了文件夹，但是文件路劲太深所以 才造成phpstorm 一直卡在了 Scanning files to index.... 状态。之后会出现提示框，也就是提示说给phpstorm分配的内存太少。但是，自己要知道，并不是分配的内存少哦。
解决：
右击 node_modules文件夹，并按如图操作点击，也就是让phpstorm不加在这个文件夹。 
如果要取消的话：
intellij idea中Mark Directory As里的Sources Root、ReSources Root等的区别：
1. Source roots (or source folders)
By assigning a folder to this category, you tell IntelliJ IDEA that this folder and its subfolders contain source code that should be compiled as part of the build process.
2. Test source roots (or test source folders; shown as rootTest)
These roots are similar to source roots but are for code intended for testing (e.g. for unit tests). Test source folders let you keep the code related to testing separate from the production code.
Compilation results for sources and test sources, normally, are placed into different folders.
3. Resource roots
are for resource files used in your application (images, various configuration XML and properties files, etc.).
During the build process, all the contents of the resource folders are copied to the output folder as is.
Similarly to sources, you can specify that your resources are generated. You can also specify which folder within the output folder your resources should be copied to.
4. Test resource roots
(or test resource folders; shown as rootTestResourceIJ; available only in Java modules) are for resource files associated with your test sources. In all other respects, these folders are similar to resource folders.
**5. Excluded roots (shown as rootExcluded) are ones that IntelliJ IDEA
“almost ignores”.**
Very limited coding assistance is provided for files in excluded folders. Classes contained in excluded folders don’t appear in code completion suggestion lists, references to such classes are shown in the editor as unresolved. When searching, IntelliJ IDEA doesn’t look in excluded folders, etc.
