Unfortunately, there is no silver bullet to know if a library is 100% LockerService compliant or not. The easiest thing to do is to create a small sample app and test the library out yourself. This will at least verify the library loads without error and you can call basic functionality.
Here are some common violations I see libraries making that cause the library not to work with LockerService enabled that you can try to manually check yourself:
- Must explicitly attach library global to
window rather than trying to declare a variable that becomes global. More info.
- CSP violations. Scan code for any usages of
new Function(), or
- DOM access. Libraries that attempt to do broad scans of the DOM rather than only manipulating elements passed to their APIs may be blocked. You should only be manipulating DOM your own namespace created.
- Use of non-standard or unsupported DOM/BOM APIs. See this app for what's exposed inside LockerService.
More details about Locker rules here.