add support for __experimentalSkiSerialization to the shadow attribute

[colinduwe]

What? This is a backport of the merged Gutenberg PR https://github.com/WordPress/gutenberg/pull/59887 When a dynamic block defines __experimentalSkipSerialization in its block.supports.shadow the styles continue to be printed to the block wrapper element. This PR corrects that behavior so that shadow behaves like border, color, and others. Why? This provides the expected behavior for dynamic blocks that need to opt out of having the shadow styles printed to the block wrapper. How? Added a check at the start of the render function to return an empty array if the block has set __experimentalSkipSerialization

(This is my first attempt at submitting a Gutenberg PR to be included back into WP Core so welcome any advice if I'm doing this wrong)

Trac ticket: https://core.trac.wordpress.org/ticket/60784#ticket

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[madhusudhand]

@madhusudhand are you aware of any PRs in progress adding unit tests for the shadow support?

I have created https://github.com/WordPress/gutenberg/pull/60063 which tests these changes.

[vcanales]

👋 @colinduwe @madhusudhand what is the status here?

It looks like https://github.com/WordPress/gutenberg/pull/60063 has been approved. Are you facing any blockers?

[colinduwe]

@vcanales I think it is probably only blocked by my ignorance of the process here. I thought this was merely awaiting approval from someone with commit access.

[aaronrobertshaw]

It looks like https://github.com/WordPress/gutenberg/pull/60063 has been approved. Are you facing any blockers?

Once https://github.com/WordPress/gutenberg/pull/60063 is merged, this should probably also include the unit test the code change relates to.

[madhusudhand]

@colinduwe could you bring the unit tests from https://github.com/WordPress/gutenberg/pull/60063 into this?

[colinduwe]

@madhusudhand I think I'm out of my depth here. I'm not sure how to do that.

[madhusudhand]

@colinduwe I have created #6613 with the unit tests. Please checkout #6613 to a branch and cherry pick the commit 8a4659608ba43363b4bd63fd76e99635c55141c8 into this PR

git fetch origin pull/6613/head:shadow-unit-tests
git cherry-pick 8a4659608ba43363b4bd63fd76e99635c55141c8

[colinduwe]

Your're a hero @madhusudhand. Thanks. Done.

[tellthemachines]

Committed in r58312.