Webstorm not recognising JavaScript file

Solution 1:

So I see three possible reasons for the problem:

1. The file was marked as 'Plain text'

2. There is a pattern for 'Text files' file type that matches this file (or back: file type 'JavaScript' exclude this file name). See image below

3. There is a custom plugin that overrides default behavior for files with this name (unlikely)

Updated: after several years I've found one more reason for the behavior and most likely it the main source of the issues. When you create a file without any extensions the "Register New File Type Association" is appeared. And you can accidentally specify a new file type, for some file name. It is can be fixed with (2) but it is the reason why the pattern was added there.

Note: the solution works for all IDEA-based IDEs: IntelliJ IDEA, WebStorm, RubyMine, PyCharm, PhpStorm.

Solution 2:

File -> Settings -> Editor -> FileTypes -> Text files -> check for "ContentRepository.js" pattern there and remove it.