feat: add support for resolving pattern blocks

.changeset/tiny-news-warn.md

@@ -0,0 +1,5 @@
+---
+"@wpengine/wp-graphql-content-blocks": minor
+---
+
+feat: add support for resolving Block Patterns

includes/Data/ContentBlocksResolver.php

@@ -151,6 +151,8 @@ private static function handle_do_block( array $block ): ?array {
 
 		$block = self::populate_reusable_blocks( $block );
 
+		$block = self::populate_pattern_inner_blocks( $block );
+
 		// Prepare innerBlocks.
 		if ( ! empty( $block['innerBlocks'] ) ) {
 			$block['innerBlocks'] = self::handle_do_blocks( $block['innerBlocks'] );
@@ -208,6 +210,32 @@ private static function populate_reusable_blocks( array $block ): array {
 		return array_merge( ...$parsed_blocks );
 	}
 
+	/**
+	 * Populates the pattern innerBlocks with the blocks from the pattern.
+	 *
+	 * @param array<string,mixed> $block The block to populate.
+	 * @return array<string,mixed> The populated block.
+	 */
+	private static function populate_pattern_inner_blocks( array $block ): array {
+		// Bail if not WP 6.6 or later.
+		if ( ! function_exists( 'resolve_pattern_blocks' ) ) {
+			return $block;
+		}
+
+		if ( 'core/pattern' !== $block['blockName'] || ! isset( $block['attrs']['slug'] ) ) {
+			return $block;
+		}
+
+		$resolved_patterns = resolve_pattern_blocks( [ $block ] );
+
+		if ( empty( $resolved_patterns ) ) {
+			return $block;
+		}
+
+		$block['innerBlocks'] = $resolved_patterns;
+		return $block;
+	}
+
 	/**
 	 * Flattens a list blocks into a single array
 	 *

tests/unit/ContentBlocksResolverTest.php

@@ -349,4 +349,68 @@ protected function assertEqualBlocks( $expected, $actual, $message = '' ) {
 			$this->assertEqualBlocks( $expected_inner_block, $actual_inner_blocks[ $index ], $message );
 		}
 	}
+
+	/**
+	 * Tests that pattern inner blocks are resolved correctly.
+	 */
+	public function test_resolve_content_blocks_resolves_pattern_inner_blocks() {
+		// Skip if pattern resolution functionality is not supported.
+		if ( ! function_exists( 'resolve_pattern_blocks' ) ) {
+			$this->markTestSkipped( 'Pattern block resolution not supported in this WordPress version.' );
+		}
+
+		// Create a pattern
+		$pattern_name = 'test/pattern-blocks';
+		$pattern_content = '
+			<!-- wp:paragraph -->
+			<p>Pattern Paragraph</p>
+			<!-- /wp:paragraph -->
+			<!-- wp:heading -->
+			<h2>Pattern Heading</h2>
+			<!-- /wp:heading -->
+		';
+
+		// Register the pattern.
+		register_block_pattern(
+			$pattern_name,
+			[
+				'title'    => 'Test Pattern',
+				'content'  => $pattern_content,
+			]
+		);
+
+		// Update post content to include pattern block.
+		$post_content = '
+			<!-- wp:pattern {"slug":"test/pattern-blocks"} /-->
+		';
+
+		wp_update_post(
+			[
+				'ID'           => $this->post_id,
+				'post_content' => $post_content,
+			]
+		);
+
+		$post_model = new Post( get_post( $this->post_id ) );
+
+		// Resolve blocks as nested.
+		$resolved_blocks = $this->instance->resolve_content_blocks( $post_model, [ 'flat' => false ] );
+
+		$this->assertCount( 1, $resolved_blocks, 'There should be only one top-level block (pattern).' );
+		$this->assertEquals( 'core/pattern', $resolved_blocks[0]['blockName'] );
+		$this->assertCount( 2, $resolved_blocks[0]['innerBlocks'], 'There should be two inner blocks in the pattern.' );
+		$this->assertEquals( 'core/paragraph', $resolved_blocks[0]['innerBlocks'][0]['blockName'] );
+		$this->assertEquals( 'core/heading', $resolved_blocks[0]['innerBlocks'][1]['blockName'] );
+
+		// Resolve blocks as flat.
+		$resolved_flat_blocks = $this->instance->resolve_content_blocks( $post_model, [ 'flat' => true ] );
+
+		$this->assertCount( 3, $resolved_flat_blocks, 'There should be three blocks when flattened.' );
+		$this->assertEquals( 'core/pattern', $resolved_flat_blocks[0]['blockName'] );
+		$this->assertEquals( 'core/paragraph', $resolved_flat_blocks[1]['blockName'] );
+		$this->assertEquals( 'core/heading', $resolved_flat_blocks[2]['blockName'] );
+
+		// Cleanup: Unregistering the pattern.
+		unregister_block_pattern( $pattern_name );
+	}
 }