Submission Review Guidelines:

• I have followed the WooCommerce Contributing Guidelines and the WordPress Coding Standards.
• I have checked to ensure there aren't other open Pull Requests for the same update/change.
• I have reviewed my code for security best practices.
• Following the above guidelines will result in quick merges and clear and detailed feedback when appropriate.

Changes proposed in this Pull Request:

By its nature, any context that a block provides will be passed from parent to child. Previously we were setting the context on all inner blocks of a Single Product block. In cases where a block was being passed a postId by a parent, this filter would override that value. This manifested in the Product Collection block where the first product shown in the block was being overridden with the Single Product block's selection.

After reviewing relevant code in Gutenberg I discovered that last year the Post Template block changed the way it passed context to inner blocks. Using this as inspiration:

• Changed the Product Template block to replicate Gutenberg's behavior.
• Reworked the Single Product block's context passing so that Gutenberg handles cascading it to children. This keeps us from setting the postId on products that may have their own plans for it. I also added the missing singleProduct context to the editor.
• Strengthened the Single Product block's global post override to apply to all inner blocks. This makes sure all inner blocks have the correct post set when rendering in case they use the post or functions that return information about the global post.

Backward Compatibility Concerns

This does come with some caveats:

• The postId and singleProduct context is not available unless a block explicitly declares it in the block.json as usesContext.
  • Anyone relying on the presence of this context without declaring it will no longer receive it.
• The postId will now cascade from the Post Template block to all inner blocks.
  • Inner blocks of the Product Collection will now have the overridden postId passed correctly through the block hierarchy.
• The global post will now be overridden for all children of the Single Product block, rather than just the post title and excerpt.

In my opinion these risks are worth accepting. The proposed behavior is better aligned with Gutenberg and ensures that inner blocks of both the Single Product and Product Collection blocks have the correct context and global post. We shouldn't encourage people to rely on secret runtime context that is automatically injected into every block.

Closes #51352.

How to test the changes in this Pull Request:

Using the WooCommerce Testing Instructions Guide, include your detailed testing instructions:

1. Create a new post.
2. Add a "Single Product" block to the page and select a product.
3. Confirm that the editor displays the correct product.
4. Confirm that the frontend displays the correct product.
5. Add a "Product Collection" block as an inner block somewhere in the "Single Product" block.
6. Confirm that the editor displays the collection correctly.
7. Confirm that the frontend displays the collection correctly.

Changelog entry

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