const hasWarned = { } ; export function warnOnce ( msg ) { const isNodeProd = typeof process !== 'undefined' && process . env . NODE_ENV === 'production' ; if ( ! isNodeProd && ! __TEST__ && ! hasWarned [ msg ] ) { hasWarned [ msg ] = true ; warn ( msg ) ; } } export function warn ( msg ) { console . warn ( `\x1b[1m\x1b[33m[@vue/compiler-sfc]\x1b[0m\x1b[33m ${ msg }\x1b[0m\n` ) ; } export function warnExperimental ( feature , url ) { if ( typeof window !== 'undefined' ) { return ; } warnOnce ( `${ feature } is still an experimental proposal.\n` + `Follow its status at ${ url }.` ) ; warnOnce ( `When using experimental features,\n` + `it is recommended to pin your vue dependencies to exact versions to avoid breakage.` ) ; }