BUGFIX Fix bargraph overflow

[bobatsar]

• If bargraphs overflow (more bars than the available space) with BarChartAlignment.start, BarChartAlignment.center or BarChartAlignment.end, use BarChartAlignment.spaceEvenly to shrink all bars to the available space
• Update documentation for BarChartData.groupsSpace

If the automatic approach to shrink all bars is not desired, another option would be to add other alignments e.g. BarChartAlignment.startShrink or another parameter to enable shrink on overflow.

[codecov]

Codecov Report

Merging #1468 (f13bbf8) into master (b3529d3) will decrease coverage by 0.22%.
The diff coverage is 81.25%.

❗ Current head f13bbf8 differs from pull request most recent head 6d5644b. Consider uploading reports for the commit 6d5644b to get more accurate results

@@            Coverage Diff             @@
##           master    #1468      +/-   ##
==========================================
- Coverage   86.67%   86.45%   -0.22%     
==========================================
  Files          45       45              
  Lines        3016     2998      -18     
==========================================
- Hits         2614     2592      -22     
- Misses        402      406       +4     

Files	Coverage Δ
lib/src/extensions/bar_chart_data_extension.dart	94.91% <81.25%> (-5.09%)	⬇️

... and 4 files with indirect coverage changes

📣 Codecov offers a browser extension for seamless coverage viewing on GitHub. Try it in Chrome or Firefox today!

[imaNNeo]

Hi, please read the Contributing guideline carefully

• You need to update the unit-tests (run make sure to make sure that everything is working well)
• You need to update the Changelog.md

[bobatsar]

@imaNNeo I just added a widget test (with golden files). I didn't find another way to check if the bars are drawn outside of the diagram. I can't check for the bars with a finder due to the fact that they are rendered on the canvas.
If you know a better approach, please tell me and I will fix it.

[imaNNeo]

Nice, I need to learn more about the golden tests.
Thanks for your contribution!

[bobatsar]

Hey @imaNNeo , thanks for merging.

For golden tests I can also recommend the following package.
I use it quite extensively e.g. for testing different device sizes.

https://pub.dev/packages/golden_toolkit

[k0psutin]

Golden tests are a good way to see if something has changed drastically. It's just that golden tests give different results on different OS - I think there should be some fault tolerance (0.2 - 0.3%) for the tests. At least for me, because I use Windows, I get failed tests on master because 0.15 - 0.2% differences.

════════════════════════════════════════════════════════════════════════════════════════════════════
00:02 +41: D:/Code/fl_chart/test/chart/bar_chart/bar_chart_alignment_widget_test.dart: Barchart alignment overflow test
══╡ EXCEPTION CAUGHT BY FLUTTER TEST FRAMEWORK ╞════════════════════════════════════════════════════
The following assertion was thrown while running async test code:
Golden "golden/BarChartAlignment.start_20.0.png": Pixel test failed, 0.20% diff detected.
Failure feedback can be found at /D:/Code/fl_chart/test/chart/bar_chart/failures

When the exception was thrown, this was the stack:
#0      LocalFileComparator.compare (package:flutter_test/src/_goldens_io.dart:101:7)
<asynchronous suspension>
<asynchronous suspension>
(elided one frame from package:stack_trace)

[k0psutin]

See https://github.com/flutter/flutter/wiki/Writing-a-golden-file-test-for-package:flutter#creating-a-new-golden-file-test

Quote from link:

Golden tests may be executed locally on Linux, MacOS, and Windows platforms. All reference images can be found at Flutter Gold baselines. Some tests may have multiple golden masters for a given test, to account for rendering differences across platforms. The parameter set for each image is listed in each image digest to differentiate renderings.

[imaNNeo]

@k0psutin You're right, I get about 93% diff on my machine 😆

[bobatsar]

@imaNNeo sorry if the golden test make issues.

@k0psutin
There is a way to add a fault tolerance.

https://stackoverflow.com/a/73048760/3607358 or
https://medium.com/mobilepeople/how-to-add-difference-tolerance-to-golden-tests-on-flutter-2d899c8baad2

I use this also for my tests in another project.
I could add this in the next days if it is wanted.

@imaNNeo but 93% diff is another level. There must be something completely off on your side. Did you check the failure images?

[k0psutin]

@k0psutin
There is a way to add a fault tolerance.

https://stackoverflow.com/a/73048760/3607358 or

I use this also for my tests in another project.
I could add this in the next days if it is wanted.

Yeah, this is how I did it for one project. I think it would be good to implement this so that, there is no need to maintain golden files for every OS.

@imaNNeo 93% sounds quite high.

Maybe the new Flutter version (3.16.0) gives that 93%?

I'm not sure if I ran it on 3.13.6 before 🤔

[imaNNeo]

No worries @bobatsar

Yes, I was in the latest version (3.16.0).
And about the OS, I think one OS might be enough with a tolerance.