Pass event objects to event handlers, please

[gka]

The d3.event + ES6 bundler nightmare is no fun to work around.

If you use Babel, Webpack, or another ES6-to-ES5 bundler, be aware that the value of d3.event changes during an event! An import of d3.event must be a live binding, so you may need to configure the bundler to import from D3’s ES6 modules rather than from the generated UMD bundle; not all bundlers observe jsnext:main.

I'd say it's one of the most basic assumptions in event driven programming that the event handler somehow gets the event object passed as argument. I don't care if it's the first or tenth argument, but please don't rely on any global d3.event or window.event sorcery.

[mbostock]

This would break everything, so I’m not going to do this for D3 5.0. I might consider it for a future major release.