Fix: properly merged schema during mergeSchemas part in getBlockContentSchemaFromTransforms - #70615

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Co-authored-by: USERSATOSHI <tusharbharti@git.wordpress.org>
Co-authored-by: sirreal <jonsurrell@git.wordpress.org>
Co-authored-by: Adi-ty <iamadisingh@git.wordpress.org>
Co-authored-by: aaronjorbin <jorbin@git.wordpress.org>
Co-authored-by: desrosj <desrosj@git.wordpress.org>
Co-authored-by: getdave <get_dave@git.wordpress.org>
Co-authored-by: SirLouen <sirlouen@git.wordpress.org>

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@getdave do you think this is ready to be shipped?

Thanks for working on this, I'd love to see this fix land.

I believe there's a remaining issue here that's unaddressed. If classes appears under children it will not merge. Here's a change to tests that captures it:

diff --git c/packages/blocks/src/api/raw-handling/test/utils.js i/packages/blocks/src/api/raw-handling/test/utils.js
index fc532c7400..ae1384dad0 100644
--- c/packages/blocks/src/api/raw-handling/test/utils.js
+++ i/packages/blocks/src/api/raw-handling/test/utils.js
@@ -128,7 +128,9 @@ describe( 'getBlockContentSchema', () => {
 						children: {
 							sub: {},
 							sup: {},
-							strong: {},
+							strong: {
+								classes: [ 'test-class' ],
+							},
 						},
 					},
 				},
@@ -146,7 +148,9 @@ describe( 'getBlockContentSchema', () => {
 		const output = {
 			pre: {
 				children: {
-					strong: {},
+					strong: {
+						classes: [ 'test-class' ],
+					},
 					em: {},
 					sub: {},
 					sup: {},

I discovered this when I tried to capture a target class below the root, but it was always stripped in my transform:

-<pre><code class="TARGET_CLASS"></code></pre>
+<pre><code></code></pre>

I've confirmed that issue remains on this branch.

@SirLouen @sirreal Hi, I’ve made the updates based on your suggestions.
Apologies for the delay. I’ve had limited bandwidth over the past few months.

I think this PR is ready for merge now, please let me know if anything else is needed.

This seems ready. @USERSATOSHI will you add a bug fix changelog entry to the package?