fix(scale): #20265 when dataZomm.filterMode is “empty” or ‘none’， the line graph is scaled to only one category, it is not filtered correctly

[linlang171]

Brief Information

This pull request is in the type of:

• bug fixing
• new feature
• others

What does this PR do?

#20265

Fixed issues

Fixes #20265
Fixes #19666

Details

Before: What was the problem?

when dataZomm.filterMode is “empty” or ‘none’， the line graph is scaled to only one category, it is not filtered correctly

After: How does it behave after the fixing?

The data is correctly filtered. And The bug is caused by calling the normalize method when calculating rendering values. When extra [1]==extra [0], it does not consider the possibility of NaN and returns 0.5 directly

Document Info

One of the following should be checked.

• This PR doesn't relate to document changes
• The document should be updated later
• The document changes have been made in apache/echarts-doc#xxx

Misc

ZRender Changes

• This PR depends on ZRender changes (ecomfe/zrender#xxx).

Related test cases or examples to use the new APIs

N.A.

Others

Merging options

• Please squash the commits into a single one when merging.

Other information

[echarts-bot]

Thanks for your contribution!
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[echarts-bot]

Document changes are required in this PR. Please also make a PR to apache/echarts-doc for document changes and update the issue id in the PR description. When the doc PR is merged, the maintainers will remove the PR: awaiting doc label.

[linlang171]

@pissang @Ovilia @100pah I have been submitting this merge request for a long time, but no one has reviewed it yet. Now I am facing this issue again. Is it possible that my merge request is incorrect, which is why it hasn't been merged? Or could you please give me some suggestions?

[helgasoft]

@linlang171, respect for your effort.
I have assembled a list of dataZoom bugs and would love to delist some of them.
Usually I do not comment on ECharts code since I don't understand it very well, want to just share some thoughts.

Your PR changes one line in function normalize. Searching further up the ladder on where it is used I find this:
normalize (helper.ts) >> ScaleCalculator (Scale.ts) >> _calculator (Interval.ts, Ordinal.ts, Time.ts)
Your test line-scale.html works with dataset, which I presume falls under Ordinal.ts. But there are two more places where normalize is used - Interval.ts and Time.ts.
Interval.ts could be related to axis and tested with xAxis.data ...? Not sure.
Testing with xAxis:{type:"time"} I find that the current code works fine. How would it work with your update I don't know.
So my point is - maybe more PR tests are needed ? Hard to tell without some feedback from developers...

[linlang171]

@100pah I found that the related codes were previously your commit. Can you help me review this pull request？

[linlang171]

@Ovilia @plainheart @100pah Could you help review this PR?

[Justin-ZS]

No blocking issues found in my review. The fix is consistent with the root cause: when the visible extent collapses to a single value, normalize() should no longer map every input to 0.5. I only see a residual test gap around edge categories / continuous axes / axis-break-specific coverage, so adding a few more regression cases would make this safer.

[Justin-ZS]

I re-reviewed this PR end to end and did not find any blocking issues. The fix now handles the collapsed-extent normalization consistently in both the regular scale path and the axis-break path, which matches the root cause described in #20265 / #19666.