Add Yoast Primary Category to WooCommerce Breadcrumbs

functions.php

<?php

/**
 * Add Yoast Primary Category to WooCommerce Breadcrumbs
 * 
 * Uses the `woocommerce_get_breadcrumb` filter
 */
 
add_filter( 'woocommerce_get_breadcrumb', 'probb_filter_wc_crumbs', 10, 2 );
function probb_filter_wc_crumbs( $crumbs, $object )
{
	//* Checking Single Product Page
	if( is_singular('product') )
	{
		//* Do nothing if shop page set as static front page
		if ( get_option( 'page_on_front' ) == wc_get_page_id( 'shop' ) )
		{
			return $crumbs;
		}

		$permalinks 	= get_option( 'woocommerce_permalinks' ); //* getting premalink structure
		$arr_shift 		= array_shift( $crumbs ); //* removing the first element "Home"
		$new_crumbs 	= array();

		//* Premalink is default then adding the shop page title into crumbs array
		if ( empty( $permalinks['product_base'] ) )
		{
			$_name = wc_get_page_id( 'shop' ) ? get_the_title( wc_get_page_id( 'shop' ) ) : '';

			if ( ! $_name )
			{
				$product_post_type = get_post_type_object( 'product' );
				$_name = $product_post_type->labels->singular_name;
			}

			$new_crumbs = array( array( $_name, get_post_type_archive_link( 'product' ) ) );
		}

		/**
		 * Checking Yoast Plugin active
		 * If it is there, then fetching the primary category name and
		 * adding into crumbs array
		 */
		if ( class_exists( 'WPSEO_Breadcrumbs' ) )
		{
			global $post;

			$terms = get_the_terms( $post, 'product_cat' );

			if ( is_array( $terms ) && $terms !== array() ) {

				$primary_term = new WPSEO_Primary_Term( 'product_cat', get_the_ID() );
				if ( $primary_term->get_primary_term() ) {

					if ( ! empty( $permalinks['product_base'] ) )
					{
						$new_crumbs[] = array_shift( $crumbs );
					}

					$breadcrumb_term 	= get_term( $primary_term->get_primary_term(), 'product_cat' );
					$ancestors 			= get_ancestors( $breadcrumb_term->term_id, 'product_cat' );
					$ancestors 			= array_reverse( $ancestors );

					foreach ( $ancestors as $ancestor ) {
						$ancestor = get_term( $ancestor, 'product_cat' );

						if ( ! is_wp_error( $ancestor ) && $ancestor ) {
							$new_crumbs[] = array( $ancestor->name, get_term_link( $ancestor ) );
						}
					}

					$new_crumbs[] 	= array( $breadcrumb_term->name, get_term_link( $breadcrumb_term ) );
					$last_element 	= array_pop( $crumbs);
					$crumbs 		= array_merge( array($arr_shift), $new_crumbs, array($last_element) );

					return $crumbs;
				}
			}
		}
 		
		//* Making the new crumbs array
		$crumbs = array_merge( array($arr_shift), $new_crumbs, $crumbs );
	}

	//* Returning the crumbs array for process
	return $crumbs;
}