(JavaScript) Top level JSX expression not detected

[modderme123]

Describe the issue

It seems like top level JSX code is not detected correctly

consider these two expressions (github highlights them correctly):

return <div> asdf </div>;

<div> asdf </div>;

which render as

Which language seems to have the issue?

javascript/jsx

Are you using highlight or highlightAuto?
highlightAll

Sample Code to Reproduce

http://jsfiddle.net/sp9cg4f1/2/

Expected behavior

I would expect that JSX code should be treated as a value and highlighted the same as when it is returned.

[joshgoebel]

I would expect that JSX code should be treated as a value and highlighted the same as when it is returned.

We have no sure way to know it's JSX code without the leading hints (=, return) to indicate we're in an expression, etc... Add a bit more context and it'll work - as you see. If you're interested in actually solving this one and wanted to submit a PR (that shows no regressions) I'm open to reviewing, but this is a really hard problem and getting JSX right without a full parser is very, very difficult.

Closing as dup of #2998.