CHARTS-18: Allow keyboard navigation for the bar chart

[Nikschavan]

Fixes CHARTS-18

Proposed changes:

• Convert the accessibility layer from the line chart to a separate component and hook to make it reusable
• Use the new tooltip component and the hook for the bar chart

https://github.com/user-attachments/assets/8dc23e6d-f9c4-49f3-ac59-15953b2c4019

Other information:

• [x] Have you written new tests for your changes, if applicable?
• [x] Have you checked the E2E test CI results, and verified that your changes do not break them?
• [x] Have you tested your changes on WordPress.com, if applicable (if so, you'll see a generated comment below with a script to run)?

Jetpack product discussion

N/A

Does this pull request change what data or activity we track or use?

No

Testing instructions:

• Start the storybook per steps in the charts library - https://github.com/Automattic/jetpack/tree/27d5924896c6c4cfabded89fa1b6247aaefd2e55/projects/js-packages/charts#storybook
• Run any bar chart storybook with tooltip and start navigating with keyboard, The tooltips should be displayed.
• First click tab to focus the bar chart and use keyboard to navigate between data points on the chart
• Use VoiceOver in Mac (or any other screenreader tool) to test how screen readers announce the contents of the tooltips

[github-actions[bot]]

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Code Coverage Summary

Coverage changed in 2 files.

File	Coverage	Δ%	Δ Uncovered
projects/js-packages/charts/src/components/bar-chart/bar-chart.tsx	68/73 (93.15%)	4.26%	-1 💚
projects/js-packages/charts/src/components/line-chart/line-chart.tsx	77/82 (93.90%)	5.27%	-10 💚

1 file is newly checked for coverage.

File	Coverage
projects/js-packages/charts/src/components/tooltip/accessible-tooltip.tsx	58/68 (85.29%) 💚

Full summary · PHP report · JS report

[github-actions[bot]]

Are you an Automattician? Please test your changes on all WordPress.com environments to help mitigate accidental explosions.

• To test on WoA, go to the Plugins menu on a WoA dev site. Click on the "Upload" button and follow the upgrade flow to be able to upload, install, and activate the Jetpack Beta plugin. Once the plugin is active, go to Jetpack > Jetpack Beta, select your plugin (Jetpack), and enable the charts-18-bar-chart-keyboard-navigation branch.
• To test on Simple, run the following command on your sandbox:

bin/jetpack-downloader test jetpack charts-18-bar-chart-keyboard-navigation

Interested in more tips and information?

• In your local development environment, use the jetpack rsync command to sync your changes to a WoA dev blog.
• Read more about our development workflow here: PCYsg-eg0-p2
• Figure out when your changes will be shipped to customers here: PCYsg-eg5-p2

[kangzj]

Known issue: For series with missing points of data, it jumps to the next one. The same happens for tooltips, please see video below:

https://github.com/user-attachments/assets/96ba65eb-ed5b-4404-a77e-20402a5bc71b