[BUG] Stepped line graph, thin lines disappear on certian screen widths

[maxymczech]

Expected Behavior

I expect to see a single thin vertical line, regardless of screen/window size

Current Behavior

The line disappears on certain screens / window sizes.

Possible Solution

Sorry, no idea, this looks like some sort of rounding issue...

Steps to Reproduce (for bugs)

https://codepen.io/anon/pen/RJQPZZ
When the width of container is set to a certain width, e.g. 352px, the line disappears.

Context

How has this issue affected you? What are you trying to accomplish?
This issue made me sad. I am trying to be happy again.

Environment

• Chart.js version: 2.7.2

[SimonLoir]

It doesn't seem to be a rounding issue because if it was rounded to 0, the graph would have been drawn anyway : when the borderwidth = 0, it seems like the graph is drawn as if the borderwidth was set.

I think it's an expected behaviour given that when the borderwidth is set to 0.15, the lines start to get smaller and nearly invisible.

[maxymczech]

Thank you for your answer. This cannot be expected behavior, because in this example it draws the line at 351 and 353px container width, but at 352px the line disappears. Also, on mobile devices / in chrome mobile mode it looks like this: https://image.ibb.co/hQAZ0J/Untitled_2.png
I.e. when in Desktop Chrome the line disappears, in Mobile Chrome with same conditions it renders a triangle instead of a thin line.

[SimonLoir]

Indeed, it's not an expected behavior at all, I was wrong.