Change:
if (!context) { context = emptyObject; } <del> var transaction = ReactUpdates.ReactReconcileTransaction.getPooled(true); this._render(element, transaction, context); ReactUpdates.ReactReconcileTransaction.release(transaction); </del> <ins> ReactUpdates.batchedUpdates(_batchedRender, this, element, context); </ins> return this.getRenderOutput(); }; <ins> function _batchedRender(renderer, element, context) { var transaction = ReactUpdates.ReactReconcileTransaction.getPooled(true); renderer._render(element, transaction, context); ReactUpdates.ReactReconcileTransaction.release(transaction); } </ins> ReactShallowRenderer.prototype.getRenderOutput = function() { return ( (this._instance && this._instance._renderedComponent &&

Discussion:
Calling on in a component being Shallow Rendered will result in the error being thrown. I set up a test case:
Who would be best to answer this one?
Seems like a valid bug report — thanks and the test case is rad. I may not be able to look at this for a while, unfortunately.
no worries let me know if you need any more info from me. This was on React 14 beta btw (not sure if that matters)
I have the same issue. A simpler example that throws the error:
Any way of getting around this issue? I am currently running into it.
Sorry about the slow response from us (FB) here. I'm the principal author of the shallow render feature, but React core isn't my main gig and I've been swamped with product work. I don't have an offhand answer for you, but I've just put time on my calendar to look into this next week. Jim, Ben, Paul — if by chance one of you happened to take care of this before then, I wouldn't be mad :)
An update on my end. I think that my problem actually went away when I deduped my npm dependencies to remove an extra react version that was causing issues. If this error pops up again I'll let you know. Thanks for the response! On Fri, Aug 28, 2015, 9:38 PM Scott Feeney wrote:
Hmm I am still able to reproduce this issue in my test case after running npm dedupe
Just to clarify, my previous comment wasn't supposed to mean that the issue has gone away. I think I was seeing a separate issue caused by multiple react versions that I misidentified as this issue (I hope that makes sense).
I am getting this error, too. I'm using react v0.14.0-rc1. Looking at the code : Apparently .
Note that shallow rendered components override to return a instead of whatever it normally returns. That still shouldn't be undefined and should have a attribute, though.
I'm experiencing this issue too - your suggestion gets me past the initial error & on to in
Pretty sure this breaks many other things outside of , but I noticed moving to be directly above in fixed this for me.
We are also affected by this issue.

I think shallow rendering is a really cool feature for testing, but unfortunately I can't use it for some of our components due to this bug.
I created pull request with a fix that works for me. Can someone else verify?
Any workaround for this issue?
:+1: Having same issue
Just ran into this too :/
Any update on this? I see that 0.14.3 was released, but these kind of tests are still failing.
I think I have to add a test to my pull request before it can be merged, but I did not get around to do it yet.
Closing in favor of which should merge soon.