Open Website

Testing and Issues

You can test this app and submit issues during the testing period of the JavaScript Chart contest.

Entries with serious issues will not be able to win the contest, but even minor issues might be important for overall results.


by rating


Fair Quokka May 8, 2019 at 11:57
— Overall performance is poor to average.
— The app is slow when scaling and scrolling the graphs.
— Sloppy on filtering and scaling the third graph.
— Values on Y-scale jitters when scrolling.
Samsung Galaxy J7 (2017), Android 8.1.0; iPhone 5S, iOS 12.1
Rich Horse May 9, 2019 at 17:37

I understand 3rd and 4th points, but could you please provide a video where I can see slow performance of my app? I just want to understand what I need to improve, and visual proof of your tips would be great.

Anyway, thanks for your review!
Bars, stacked: incorrect cursor, finger position detection
MBP 2018 15, Mojave, Chrome
Rich Horse Apr 23, 2019 at 14:21
Whoa! I thought I fixed it! Looks like something went wrong. As far as I understand, it works in this way only at the end of the chart.

Good catch, thanks!
Giant Parrot Apr 21, 2019 at 05:55
1. The Y axes bottom values are changed with no transition.
2. The bar chart changes its shape during a zooming. I understand it's done for an optimization but it's too explicit.
3. The line gets toggled when I move the trimmer and release the mouse over a button.
MacBook Pro 2015 / Safari 12.1
Rich Horse Apr 21, 2019 at 07:17
1. Yes. It's sort of optimisation. But you're right, it should be better. Now it isn't obvious where the grid is moving: up or down.

2. Oh, no, it's not for optimisation purposes. It's for recalculation of min height of each bar part. I think I can animate these changes and they will be smoother.

3. Yo! Great catch!

Thank you for the good review, I really appreciate it :-)
Stout Jackal Apr 17, 2019 at 12:26
like change values animation; and minimum height for small values in stacked bar chart
Rich Horse Apr 18, 2019 at 17:41
Дмитрий Потапов Apr 17, 2019 at 13:46
Administrators Telegram, where my graphics? Yesterday I sent a zip archive, but I do not see my work in the list
Slim Peacock Apr 18, 2019 at 17:28
- perfomace issues on Fruits chart when resizing, unchecking values, dragging, showing tooltip

- page zooming allowed on mobiles

- day-month-year change should be animated separately

- wrong value change animation in tooltip

- array of data built into page
BQ strike mini, 4x1.3Hhz, 1Gb RAM, Chrome, Android 7
Rich Horse Apr 18, 2019 at 17:40
1. Attach the video, please.

2. There were no any rules restricting it.

3. There is no any animation of date at all. The reasons are described in README.

4. Attach the video with comparison, please. Or maybe you need to check README where I described the reasons why values in a tooltip are animated in this way. Short brief: there were no examples of big amounts of data animations in Telegram's video, so I decided that my way of animation is a bit better that just “animate each step”, because in my case there is not so many blinking.

5. It is not agains the rules, isn't it? I didn't choose to implement bonus goal, so there is no big deal with inlined data. It's just for decreasing page load time, and it is not affect your UX of the chart in any ways.

If it's possible, please, attach the videos that I requested, it will help me to improve the library.

Thank you for your review!
Line charts: circles on chosed date is cut off
MBP 2018 15, Mojave, Chrome
Rich Horse Apr 19, 2019 at 20:52
Yeah, I know about it. Just need to swap two lines of code.

Thanks for your review, anyway :-)
Stacked: min height for red data is too big. 160 vs 5700 and almost same height
MBP 2018 15, Mojave, Chrome
Rich Horse Apr 19, 2019 at 21:05
I don't think it's an issue here.

First of all, min height of bars is the same as in provided design.

Second, yes, it was possible to decrease its size, but I think 6px was a good choice. Another possible sizes are 5 or 4px (the less is definitely the worse), but even with these values there wouldn't be much difference between bars with 60 and 5700 (maybe there would be switch from 1:2 to 1:3 ratio, but I'm not sure).

So, why not to make the UI as much as possible the same as it was designed, right?
The dates are not in the same format as in the contest requirements. Probably a very small issue and could be ignored.

A very decent work. The design is nice, animations are stable and slick. I see absolutely no reason why this work should have received so many dislikes.
Chrome 73
Rich Horse Apr 22, 2019 at 22:12
Thank you! :-)

(I noticed wrong format right after publishing my work. It was a little bit sad, because I tried to make it as near to design as possible, and completely forgot about date format.

Same for font face & size of chart headers. I don't know why I didn't recheck them. Shame on me.)
Nobody added any issues yet...