I don't know what I'm missing here, but for some reason the gridlines don't seem to render with a XY Plot component. Not sure if I need to place the components in a certain order, or specify certain properties for the gridlines.
Here's a preview of what the graph looks like

and the ordering of my components.
class Graph extends Component {
render() {
return (
<div className="graph">
<XYPlot
width={1100}
height={300}>
<HorizontalGridLines />
<VerticalBarSeries
data={impressions}
/>
<VerticalGridLines />
<XAxis tickTotal={10} tickSize={3} />
<YAxis />
</XYPlot>
</div>
);
}
}
Not sure if we can set a strokewidth property on this, right now there's no width.

I was able to get them to show by specifying the line thickness on the css class.
.rv-xy-plot__grid-lines__line {
stroke: gray;
stroke-width: 1;
}
Would be nice if these were set by default.
I know this issue is closed but to avoid other people wasting time (I've been trough the same problem!):
Do not forget to add the stylesheet to your app. There are instructions in the Readme.
Thanks, @Lobosque. Where is this documented? I'm not seeing the instructions here, which is where I expected to find this kind of information.
for anyone else coming here, like me, i found info on importing the styles here: https://github.com/uber/react-vis/blob/master/docs/getting-started/getting-started.md
i decided to import the styles into my component since it's only needed in one place:
import '../node_modules/react-vis/dist/style.css';
or just:
import 'react-vis/dist/style.css';
Most helpful comment
I know this issue is closed but to avoid other people wasting time (I've been trough the same problem!):
Do not forget to add the stylesheet to your app. There are instructions in the Readme.