guard-function:你不可以过去！

保护功能 使用谓词保护功能。 安装 npm install guard-function 用法 基本用法 var guard = require ( 'guard-function' ) ; let capitalize = ( str ) => str . charAt ( 0 ) . toUpperCase ( ) + str . slice ( 1 ) ; // Silently fail when non-string is passed in capitalize = guard ( ( str ) => typeof str === 'string' , capitalize ) ; capitalize ( 12 ) ; // => undefined capitalize ( "you shall not pass!" ) ; // => "You shall not