merge json recursive

merge_json_recursive.php

<?php

function custom_merge_recursive( $original_schema, $schema_to_merge ) {
	$get_value_by_path = function ( $path, $data ) {
		$current = $data;

		foreach ( $path as $key ) {
			if ( ! isset( $current[ $key ] ) ) {
				return null;
			}
			$current = $current[ $key ];
		}

		return $current;
	};

	$map_custom_recursive = function ( $callback, $needle ) use ( &$map_custom_recursive ) {
		$result = [];
		static $path = [];

		foreach ( $needle as $key => $value ) {
			$path [] = $key;

			$result[ $key ] = $callback( $value, $path );

			if ( is_array( $value ) ) {
				$map_custom_recursive( $callback, $value );
			}

			array_pop( $path );
		}

		return $result;
	};

	return $map_custom_recursive( function ( $value, $path ) use ( $original_schema, $get_value_by_path ) {
		$original_value = $get_value_by_path( $path, $original_schema );

		if ( null === $original_value ) {
			return $value;
		}

		if ( is_array( $original_value ) ) {
			return array_merge_recursive( $original_value, $value );
		}

		return $original_value;
	}, $schema_to_merge );
}