aforsell,
Sorry that you are seeing this issue. I could not replicate the problem at my end.
Can you please give us some more details to help us investigate further?
1. Can you please clarify if you are comparing JS files with each other or a JS file with its previous version in the local history or in a repository?
2. It could also be an issue with the file contents. Do you have any special constructs like classes or using JSX in your JS files? If possible, please share with us sample JS files to help us replicate the issue at our end.
3. Do you see the problem with all the JS files in the workspace or only with specific JS files? How about Java compare? Does that work fine?
4. Do you see any errors logged in the Error Log view when you invoke the JS compare? If yes, then share with us the workspace log file by clicking on the icon for ‘Export Log’ in the Error Log view,save it as .txt file and attach it here. Also please share with us the Eclipse version details from Help > About Eclipse dialog.
5. Can you please clarify if the compare works for those files in Eclipse without CodeMix? To check the same, you can go to Window > Preferences > CodeMix, temporarily disable CodeMix, restart the IDE and see how it works.
Apologies for inconvenience caused.
–Swapna
Genuitec Support