Checks if the given argument is a writable stream.
Check if the value is different from null
, use typeof
to check if the value is of type object
and the pipe
property is of type function
.
Additionally check if the typeof
the _write
and _writableState
properties are function
and object
respectively.
代码片段
const isWritableStream = val =>
val !== null &&
typeof val === 'object' &&
typeof val.pipe === 'function' &&
typeof val._write === 'function' &&
typeof val._writableState === 'object';
使用样例
const fs = require('fs');
isWritableStream(fs.createWriteStream('test.txt')); // true