Fix wp_template renaming when hooked_block_types filter exists

[alshakero]

The ticket explains the problem.

Trac ticket: https://core.trac.wordpress.org/ticket/61550

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Props alshakero, bernhard-reiter.

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[ockham]

LGTM! Thank you very much for the fix!

[ockham]

Apologies, I might've spoken too soon 😅

I remembered to look at the comment for this PR that fixed the same issue for wp_navigation post types.

Note this comment on using isset vs empty:

empty() is bad, because it would miss the cases where the post_content is legitimately changed to an empty string. isset() is better.

Specifically, per #6867, we could hit an edge case where a hooked block would be injected as the first or last child of an (otherwise empty) Template Part block. If we use empty(), this isn't going to work.

We should probably add some test coverage in tests/phpunit/tests/block-templates/injectIgnoredHookedBlocksMetadataAttributes.php to cover the case where $changes->post_content isn't set (to make sure that https://core.trac.wordpress.org/ticket/61550 is fixed), and another test to cover the case I described in the previous paragraph.

(I can take care of those things next week if you don't have time. Unfortunately, this will mean the fix won't make it into 6.6.1 and will have to wait for 6.6.2 instead.)

[alshakero]

Oooh great catch! How about array_key_exists property_exists which seems even more careful?

[ockham]

Oooh great catch! How about array_key_exists property_exists which seems even more careful?

So the only difference between property_exists() and isset() is that the latter returns false if the property exists but is null, right? In that case, I'd stick with if ( ! isset( $changes->post_content ) ) { return $changes; }, since it'll bail if $changes->post_content === null. This is fine IMO, since it's unclear how we'd otherwise apply the Block Hooks algorithm to a post content that's null; we'd effectively have to cast it to '' after all.

It's also more consistent with what we're doing with wp_navigation 🙂 Finally, it's hopefully a rather academic scenario only that $changes->post_content === null.

[alshakero]

Hi @ockham! Thanks for addressing your feedback. I was working on it at the same time and only realized because I couldn't push. Here's my take on the test in case it helps

/**
	 * @ticket 61550
	 */
	public function test_hooked_block_types_filter_with_renamed_template_part() {
		$action = new MockAction();
		add_filter( 'hooked_block_types', array( $action, 'filter' ), 10, 4 );

		$changes             = new stdClass();
		$changes->ID         = 1;
		$changes->post_type  = 'wp_template_part';
		$changes->post_title = 'new title';
		$cloned_changes      = unserialize( serialize( $changes ) );

		$result = inject_ignored_hooked_blocks_metadata_attributes( $changes );

		// Ensure same reference.
		$this->assertSame(
			$changes,
			$result,
			'Should leave the changes object untouched if `post_content` is not set.'
		);

		// Ensure same values.
		$this->assertTrue(
			$result == $cloned_changes, // phpcs:ignore Universal.Operators.StrictComparisons.LooseEqual -- == compares all props and their values.
			'Should leave the changes object untouched if `post_content` is not set.'
		);

		$changes               = new stdClass();
		$changes->ID           = 1;
		$changes->post_type    = 'wp_template_part';
		$changes->post_title   = 'new title';
		$changes->post_content = 'new content';
		$cloned_changes        = unserialize( serialize( $changes ) );

		$result = inject_ignored_hooked_blocks_metadata_attributes( $changes );

		$this->assertNotSame(
			$changes,
			$result,
			'Should process the changes object if `post_content` is set.'
		);

		$changes               = new stdClass();
		$changes->ID           = 1;
		$changes->post_type    = 'wp_template_part';
		$changes->post_title   = 'new title';
		$changes->post_content = '';
		$cloned_changes        = unserialize( serialize( $changes ) );

		$result = inject_ignored_hooked_blocks_metadata_attributes( $changes );

		$this->assertNotSame(
			$changes,
			$result,
			'Should process the changes object if `post_content` is set to an empty string.'
		);
	}

[ockham]

Hi @ockham! Thanks for addressing your feedback. I was working on it at the same time and only realized because I couldn't push.

Oh no, I should've posted a comment to let you know! Apologies, I didn't mean to make you duplicate work.

Anyway, thank you for sharing your patch! I'll have a look if there's anything to incorporate into the tests and will probably land the PR later today 😊

[ockham]

Committed to Core in https://core.trac.wordpress.org/changeset/58785.

[ockham]

Backported to the 6.6 branch in https://core.trac.wordpress.org/changeset/58802.