使用through2在Node.js中向流发送数据时增加换行符

Question

我正在通过溪流-冒险工作狂从NodeSchool。我将编写一个程序，将process.stdin流连接到使用through2模块创建的流中，然后将其输送到process.stdout。使用through2模块创建的流将将输入流字符转换为大写，并将其输送到process.stdout。下面是我的源代码：

var through = require('through2');
var write = function(buffer,encoding,next){
        var data = buffer.toString();
        this.push(data.toUpperCase() + '\n');
        next();
}
var end = function (done){
        done();
}
var stream = through(write,end);
process.stdin.pipe(stream).pipe(process.stdout);

问题是，在每8块字发送到流后，就会多打印一条换行符。下面是工作人员进行的验证的3个测试输出：

试验1：

TAP version 13
# (anonymous)
ok 1 stream-adventure verify YOURFILE.js
not ok 2 should be equal
  ---
    operator: equal
    expected:
      'METALKIND\nKORVEN\nOSIRIAN\nTHE ERGON\nTYTHONIAN\nLAND OF FICTION BEINGS\nSIRIAN\nKRAAL\nTHE FLOOD\nJADONDAN\n'
    actual:
      'METALKIND\nKORVEN\nOSIRIAN\nTHE ERGON\nTYTHONIAN\nLAND OF FICTION BEINGS\nSIRIAN\nKRAAL\n\nTHE FLOOD\n\nJADONDAN\n\n'
  ...
ok 3 successful exit code

1..3
# tests 3
# pass  2
# fail  1

#########################################
###   YOUR SOLUTION IS NOT CORRECT!   ###
#########################################

试验2：

TAP version 13
# (anonymous)
ok 1 stream-adventure verify YOURFILE.js
not ok 2 should be equal
  ---
    operator: equal
    expected:
      'THE BEAST\nANDROZANI TREE\nGAZTAK\nRAXACORICOFALLAPATORIAN\nMAYFLY\nSTIGORAX\nTHE TRICKSTER\nMEGARA\nMENTOR\nHAND OF OMEGA\n'
    actual:
      'THE BEAST\nANDROZANI TREE\nGAZTAK\nRAXACORICOFALLAPATORIAN\nMAYFLY\nSTIGORAX\nTHE TRICKSTER\nMEGARA\nMENTOR\n\nHAND OF OMEGA\n\n'
  ...
ok 3 successful exit code

1..3
# tests 3
# pass  2
# fail  1

#########################################
###   YOUR SOLUTION IS NOT CORRECT!   ###
#########################################

试验3：

TAP version 13
# (anonymous)
ok 1 stream-adventure verify YOURFILE.js
not ok 2 should be equal
  ---
    operator: equal
    expected:
      'QETESH\nPELUSHI\nLURMAN\nEVE\nATRAXI\nFLESHKIND\nDALEK\nGEE-JEE FLY\nHEADLESS MONK\nTHE DESTROYER\n'
    actual:
      'QETESH\nPELUSHI\nLURMAN\nEVE\nATRAXI\nFLESHKIND\nDALEK\nGEE-JEE FLY\n\nHEADLESS MONK\n\nTHE DESTROYER\n\n'
  ...
ok 3 successful exit code

1..3
# tests 3
# pass  2
# fail  1

#########################################
###   YOUR SOLUTION IS NOT CORRECT!   ###
#########################################

神秘的额外换行符的原因是什么?我如何修复它？

Answer 1

代码中的第4行将添加额外的换行符。要解决这个问题，您可以从下面更改第4行：

this.push(data.toUpperCase() + '\n');

对此：

this.push(data.toUpperCase());

此外，当您在终端中键入此内容时，流冒险课将打印它们的参考解决方案。

stream-adventure solution 

Answer 2

不要添加'\n‘，它已经在流中了。我猜您得到的缓冲区不止一行，因此“\n”被随机添加。