module-info is a new source file used on Java projects for module declaration. It will be released on jdk9 (7/17/2017) as part of project Jigsaw. For now, the file does not have hightlight support as you can see here.

I don't know about this file yet, but reading the specification:

open, module, requires, transitive, exports, opens, to, uses, provides, and with are restricted keywords (...)

(...) A module name consists of one or more Java identifiers separated by "." tokens. In the declaration of a module name (after module) and in any use of a module name (by requires, exports, or opens), every identifier in the name must end with a Java letter, or a compile-time error occurs.

Annotations and static/transitive modifiers are allowed too.

This information is sufficient to add support for this file?

I opened an issue in the repository of the linguist (#3566), but they asked me to open the issue in this repository.

- cheers.