使用非常流行的stream-buffers包，你可能已经在你的项目依赖项中有了这个包，这是非常简单的:

// imports
const { WritableStreamBuffer } = require('stream-buffers');
const { promisify } = require('util');
const { createReadStream } = require('fs');
const pipeline = promisify(require('stream').pipeline);

// sample stream
let stream = createReadStream('/etc/hosts');

// pipeline the stream into a buffer, and print the contents when done
let buf = new WritableStreamBuffer();
pipeline(stream, buf).then(() => console.log(buf.getContents().toString()));

希望这比上面的答案更有用:

var string = '';
stream.on('data',function(data){
  string += data.toString();
  console.log('stream data ' + part);
});

stream.on('end',function(){
  console.log('final output ' + string);
});

请注意，字符串连接并不是收集字符串部分的最有效方法，但使用它是为了简单(也许您的代码并不关心效率)。

此外，对于非ascii文本，这段代码可能会产生不可预测的失败(它假设每个字符都适合一个字节)，但也许您也不关心这一点。

这对我来说是有效的，并且基于Node v6.7.0文档:

let output = '';
stream.on('readable', function() {
    let read = stream.read();
    if (read !== null) {
        // New stream data is available
        output += read.toString();
    } else {
        // Stream is now finished when read is null.
        // You can callback here e.g.:
        callback(null, output);
    }
});

stream.on('error', function(err) {
  callback(err, null);
})

最简洁的解决方案可能是使用“string-stream”包，它将流转换为带有承诺的字符串。

const streamString = require('stream-string')

streamString(myStream).then(string_variable => {
    // myStream was converted to a string, and that string is stored in string_variable
    console.log(string_variable)

}).catch(err => {
     // myStream emitted an error event (err), so the promise from stream-string was rejected
    throw err
})

另一种方法是将流转换为promise(参考下面的示例)，然后使用then(或await)将解析值分配给变量。

function streamToString (stream) {
  const chunks = [];
  return new Promise((resolve, reject) => {
    stream.on('data', (chunk) => chunks.push(Buffer.from(chunk)));
    stream.on('error', (err) => reject(err));
    stream.on('end', () => resolve(Buffer.concat(chunks).toString('utf8')));
  })
}

const result = await streamToString(stream)

我更幸运的是这样使用:

let string = '';
readstream
    .on('data', (buf) => string += buf.toString())
    .on('end', () => console.log(string));

我使用节点v9.11.1, readstream是来自http的响应。回调。