[BUG] Removing a dataset in onClick causes an error if the mouse is moved right after clicking

[rmja]

The problem happens because the lastActive array which is set here contains the active element which is removed in the onClick, so in the following mousemove event happening after the mouseup event fails because this line contains the removed element, and the call to updateHoverStyle() fails because the dataset is not present anymore.

Expected Behavior

It should be possible to remove a dataset within onClick() and move the mouse just after without any error.

Possible Solution

Update lastActive in the top of handleEvent so that it only includes elements which are still present on the chart.

This hack is a temporary workaround:

                   onHover: function(event, elements) {
                        if (self.chart.data.datasets.length === 0) {
                            this.active.length = 0;
                            this.lastActive.length = 0;
                        }
                    }

[etimberg]

@rmja can you post a fiddle that reproduces this?

[timwis]

I'm experiencing this as well. Here's a demo. To reproduce it, open your JavaScript console (not the one that comes with Codepen), then click on one of the bars. You'll see the second dataset disappear. If you then move your mouse, you'll see your console flooded with errors.