Uncaught TypeError: Cannot read property 'previousSibling' of null

[piotrpalek]

Hey I was trying to port my app to ember 1.13.1 and started getting this error when transitioning to other routes. I will try to make a jsbin later on, just posting this in case it is something known.
The error occurs here:

    removeRange: function removeRange(firstNode, lastNode) {
      var node = lastNode;
      do {
        var next = node.previousSibling; // <-- error from issue title

[piotrpalek]

Ok I didn't manage to replicate it in a jsbin (don't know if/how it's possible to load the addon there) but here's a really simple example app: https://github.com/piotrpalek/wormhole-bug which shows the bug. You have to run the app and click the Second link and it will trigger the error.

[piotrpalek]

@lukemelia I saw you looked at a similiar issue (#9) do you think this could be also ember related?

[krisselden]

This should have been fixed with emberjs/ember.js#11425 but you are hitting it in 1.13.1? If so, I'd love some help tracking it down. If you could make a jsbin or fiddle replicating it would be greatly appreciated. Also, if you can set a breakpoint in wormhole willDestroyElement to see if it is being called twice and include the stack trace of both calls that would be helpful.

[piotrpalek]

@krisselden yes even in 1.13.2, I provided a link above to an example app, I am not sure how to setup a jsfiddle with an ember-cli addon (in this case ember-wormhole). Do you have some base jsbin (ember+wormhole) where I could show the bug, assuming the above github repo isn't enough?

[piotrpalek]

@krisselden so the willDestroyElement method isn't called twice, but I noticed that here:

    willDestroyElement: function willDestroyElement() {
      var _this = this;

      var firstNode = this._firstNode;
      var lastNode = this._lastNode; // <-- the same as firstNode
      run.schedule('render', function () {
        _this.removeRange(firstNode, lastNode);
      });
    }

firstNode and lastNode is the same. So later in removeRange (where the error occurs):

    removeRange: function removeRange(firstNode, lastNode) {
      var node = lastNode;
      do {
        var next = node.previousSibling; // error occurs here, I assume that's because it doesn't have a previousSibling since it's the first node?
        if (node.parentNode) {
          node.parentNode.removeChild(node);
        }
        node = next;
      } while (node !== firstNode);
    }

[krisselden]

@piotrpalek thanks, this is definitely then a wormhole bug. Do you want to submit a PR? I know that this code handles this case https://github.com/krisselden/morph-range/blob/master/lib/morph-range/utils.js#L10-L14

[piotrpalek]

@krisselden I've made a PR, but as noted there, I tried to write a test for this but when I bumped the ember version to 1.13 in the addon, other tests were breaking as well. So I couldn't really test this without fixing all of them.
I also will have to maintain a seperate branch with this fix applied to the 0.3.1 version of ember-wormhole, because master doesn't work with https://github.com/yapplabs/ember-modal-dialog which I am also using.