Blocks: Refactor the check against self for block hooks

src/wp-includes/class-wp-block-type.php

@@ -522,6 +522,15 @@ public function set_props( $args ) {
 		$args = apply_filters( 'register_block_type_args', $args, $this->name );
 
 		foreach ( $args as $property_name => $property_value ) {
+			// Avoid infinite recursion in block hooks (hooking to itself).
+			if ( 'block_hooks' === $property_name && array_key_exists( $this->name, $property_value ) ) {
+				_doing_it_wrong(
+					__METHOD__,
+					__( 'Cannot hook block to itself.' ),
+					'6.4.0'
+				);
+				unset( $property_value[ $this->name ] );
+			}
 			$this->$property_name = $property_value;
 		}
 	}

tests/phpunit/data/blocks/notice/block.json

@@ -31,7 +31,10 @@
 		"root": ".wp-block-notice"
 	},
 	"blockHooks": {
-		"core/post-content": "before"
+		"tests/before": "before",
+		"tests/after": "after",
+		"tests/first-child": "firstChild",
+		"tests/last-child": "lastChild"
 	},
 	"supports": {
 		"align": true,

tests/phpunit/tests/blocks/register.php

@@ -645,8 +645,13 @@ public function test_block_registers_with_metadata_fixture() {
 			'Block type should contain selectors from metadata.'
 		);
 		// @ticket 59346
-		$this->assertSame(
-			array( 'core/post-content' => 'before' ),
+		$this->assertSameSets(
+			array(
+				'tests/before'      => 'before',
+				'tests/after'       => 'after',
+				'tests/first-child' => 'first_child',
+				'tests/last-child'  => 'last_child',
+			),
 			$result->block_hooks,
 			'Block type should contain block hooks from metadata.'
 		);
@@ -1069,4 +1074,29 @@ public function test_register_block_style_name_without_spaces() {
 		$actual = register_block_style( 'core/query', $block_styles );
 		$this->assertTrue( $actual );
 	}
+
+	/**
+	 * @ticket 59346
+	 *
+	 * @covers ::register_block_type
+	 *
+	 * @expectedIncorrectUsage WP_Block_Type::set_props
+	 */
+	public function test_register_block_hooks_targeting_itself() {
+		$block_name = 'tests/block-name';
+		$block_type = register_block_type(
+			$block_name,
+			array(
+				'block_hooks' => array(
+					$block_name         => 'first',
+					'tests/other-block' => 'last',
+				),
+			)
+		);
+
+		$this->assertSameSets(
+			array( 'tests/other-block' => 'last' ),
+			$block_type->block_hooks
+		 );
+	}
 }