tag-to-content-node-connection.php

add_action( 'graphql_register_types', function() {
	register_graphql_connection([
		'fromType' => 'Tag',
		'toType' => 'ContentNode',
		'fromFieldName' => 'contentNodes',
		'resolve' => function( \WPGraphQL\Model\Term $source, $args, $context, $info ) {
			// Get all post types allowed in GraphQL
			$post_types = WPGraphQL::get_allowed_post_types();

			// Instantiate a new PostObjectConnectionResolver class
			$resolver = new \WPGraphQL\Data\Connection\PostObjectConnectionResolver( $source, $args, $context, $info, $post_types );

			// Set the argument that will be passed to WP_Query. We want only Posts (of any post type) that are tagged with this Tag's ID
			$resolver->set_query_arg( 'tag_id', $source->term_id );

			// Return the connection
			return $resolver->get_connection();
		}
	]);
} );