Add typescript

[bbovenzi]

Add typescript support for the current UI project in /airflow/www.

• Include type checking as part of the yarn lint checks
• Add example .tsx and .test.tsx files with the Time component and fix some associated typing issues

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In case of fundamental code change, Airflow Improvement Proposal (AIP) is needed.
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[pierrejeambrun]

Really nice!

I guess that ts is the new standard from now on ? (Also updating existing code each time we have the opportunity to)

[bbovenzi]

Really nice!

I guess that ts is the new standard from now on ? (Also updating existing code each time we have the opportunity to)

Yep. That's the plan. We can migrate js files over time and across PRs.

[mik-laj]

Should we also add typescript-eslint?

[bbovenzi]

Yeah, I was playing around with it. Let me make sure it's in this PR.

[bbovenzi]

Added!

[github-actions]

The PR is likely OK to be merged with just subset of tests for default Python and Database versions without running the full matrix of tests, because it does not modify the core of Airflow. If the committers decide that the full tests matrix is needed, they will add the label 'full tests needed'. Then you should rebase to the latest main or amend the last commit of the PR, and push it with --force-with-lease.

[uranusjr]

🎉

[potiuk]

Cool! Maybe finally some chance to contribute to the UI part :)