const VALID_STYLES = [ 'css', 'scss', 'less', 'styl', 'styled-components', '@emotion/styled', 'styled-jsx', 'none', ]; export function assertValidStyle(style: string): void { if (VALID_STYLES.indexOf(style) === -1) { throw new Error( `Unsupported style option found: ${style}. Valid values are: "${VALID_STYLES.join( '", "' )}"` ); } }