/**
 * Requires
 */
@use 'sass:map';
@use 'sass:meta';

/**
 * Optionally merges two maps
 * @param {map} $base - Base map to merge into
 * @param {null|false|map} $extend - Optional extension map
 * @return {map} - Merged or base map
 */
@function merge-optional($base, $extend: null, $error: 'merge-optional::') {

  // Base must be a map
  @if meta.type-of($base) != map {
    @error '#{$error}base[#{meta.type-of($base)}] must be a map containing at least one name, value pair';
  }
  $compiled: $base;

  // Conditional merge
  @if $extend {

    // Extend must be a map
    @if meta.type-of($base) != map {
      @error '#{$error}extend[#{meta.type-of($extend)}] must be null, false or a map containing at least one name, value pair';
    }

    // Merge maps
    $compiled: map.merge($compiled, $extend);
  }
  @return $compiled;
}