spy wrapping test doesn't work on non ES6 enviroments. about ospec HOT 5 CLOSED

It isn't mine either :-)

The goal is to improve ospec incrementally, since we won't port the Mithril test suite...

from ospec.

Edit: scratch that: I read your post too fast

from ospec.

Yes, I can reproduce it actually. Old JavaScriptCore (i.e. old WebKit, on which PhantomJS is built) version treat name and length as read-only properties on functions.

I don't think we should care about PhantomJS though, since the repro works fine in Safari 10+.

However, attempting to set fn.length in IE 11 also throws a similar error, even though fn.name can be overwritten. We could use eval or new Function to implement the spies, or wrap the part where we set the lenght in a try/catch block and ignore the error...

from ospec.

POC which passes the current tests and then some.

So, the POC as a gist works in Safari 8 and 9, and it works as well as it can in IE 11 (since fn.name is always undefined unless you set it manually, which is kind of pointless... edit: pointless except perhaps in transpiled code...).

Updated flems which detects the issue and only falls back on eval if needed.

from ospec.

Feel free to file a pull request. It's a pretty easy issue to resolve.

IME spies are usually the wrong thing to use anyways, but this isn't my framework.

from ospec.