Javascript管道未捕获我抛出的错误

我有一个管道，在其中一个转换中我抛出了一个错误，我想以某种方式捕捉它

_transform(chunk,encoding,done) {
    let strChunk = decoder.write(chunk);
    if(strChunk === '\u0003')
        process.exit();
    let felem = JSON.parse(strChunk);
    let seq = felem.seq.replace(/\s+/g, '');
    this.type = "nucleotide";
    for(let i=0; i<this.checkMax && i<seq.length; i++) {
        let c = seq[i];
        if(!(c in this.nucleotides) && (c in this.aminoacids)) {
            this.type = "aminoacid";
            felem["type"]=this.type;
            if((this.forward === "both") || (this.forward === this.type))
                this.push(JSON.stringify(felem));             
            break;
        } else {
            if(!(c in this.nucleotides) && !(c in this.aminoacids) && !(c in this.permissables)) {
                throw new Error("Unexpected character in sequence (" + felem.def + "): " + c + ".");
            }
        }

    }
    done();
}

不幸的是，非.on（'error'或err=>函数正在启动，我得到了未捕获的错误：…加上堆栈跟踪： 第一行是指我抛出错误的位置

  at FASTASeqType._transform (h:\Code\ios\src\FASTA\FASTASeqType.js:41:27)
  at FASTASeqType.Transform._read (_stream_transform.js:191:10)
  at FASTASeqType.Transform._write (_stream_transform.js:179:12)
  at doWrite (_stream_writable.js:403:12)
  at writeOrBuffer (_stream_writable.js:387:5)
  at FASTASeqType.Writable.write (_stream_writable.js:318:11)
  at FASTAElement.ondata (_stream_readable.js:695:22)
  at addChunk (_stream_readable.js:286:12)
  at readableAddChunk (_stream_readable.js:268:9)
  at FASTAElement.Readable.push (_stream_readable.js:209:10)
  at FASTAElement.Transform.push (_stream_transform.js:152:32)
  at FASTAElement._transform (h:\Code\ios\src\FASTA\FASTAElement.js:27:22)
  at FASTAElement.Transform._read (_stream_transform.js:191:10)
  at FASTAElement.Transform._write (_stream_transform.js:179:12)
  at doWrite (_stream_writable.js:403:12)
  at writeOrBuffer (_stream_writable.js:387:5)
  at FASTAElement.Writable.write (_stream_writable.js:318:11)
  at Transform.ondata (h:\Code\ios\src\node_modules\readable-stream\lib\_stream_readable.js:681:20)
  at addChunk (h:\Code\ios\src\node_modules\readable-stream\lib\_stream_readable.js:298:12)
  at readableAddChunk (h:\Code\ios\src\node_modules\readable-stream\lib\_stream_readable.js:280:11)
  at Transform.Readable.push (h:\Code\ios\src\node_modules\readable-stream\lib\_stream_readable.js:241:10)
  at Transform.push (h:\Code\ios\src\node_modules\readable-stream\lib\_stream_transform.js:139:32)
  at push (h:\Code\ios\src\node_modules\split2\index.js:65:10)
  at Transform.transform [as _transform] (h:\Code\ios\src\node_modules\split2\index.js:43:5)
  at Transform._read (h:\Code\ios\src\node_modules\readable-stream\lib\_stream_transform.js:177:10)
  at Transform._write (h:\Code\ios\src\node_modules\readable-stream\lib\_stream_transform.js:164:83)
  at doWrite (h:\Code\ios\src\node_modules\readable-stream\lib\_stream_writable.js:409:139)
  at writeOrBuffer (h:\Code\ios\src\node_modules\readable-stream\lib\_stream_writable.js:398:5)
  at Transform.Writable.write (h:\Code\ios\src\node_modules\readable-stream\lib\_stream_writable.js:307:11)
  at ReadStream.ondata (_stream_readable.js:695:22)
  at addChunk (_stream_readable.js:286:12)
  at readableAddChunk (_stream_readable.js:268:9)
  at ReadStream.Readable.push (_stream_readable.js:209:10)
  at internal/fs/streams.js:210:12
  at FSReqCallback.wrapper [as oncomplete] (fs.js:488:5)

---

怎么办？

如果错误与流相关，则需要分别为读流和写流添加

错误

事件处理程序

let inStream = fs.createReadStream("../files/bad.fasta").on('error', (err) => console.log(err));
let outStream = fs.createWriteStream("../files/bad_typed.fasta").on('error', (err) => console.log(err));

---

请记住，如果您有更多的流，则每个流都必须单独处理。

我应用了该建议（请参见代码编辑）。但是，没有调用任何.on错误处理程序。您是否尝试过

expect（pipeline（…）.to.throw（）；

？我拉出管道并将其命名为

函数pip（）{pipeline（…）；

。然后我执行了

expect（pip）.to.throw（“…”）

；未捕获的错误消息消失了，但仍然没有在任何地方捕获到错误，我得到：

AssertionError:expected[Function:pip]要从mocha抛出一个错误

。您需要调用它，请在我将

expect（pip（））.to.throw（“…”

改为.throw（“…”）；I get:`AssertionError:expected undefined to a function`。因此我认为chai希望调用函数本身。请参阅：只是将所有内容包装在try..catch中。没有更改。它与使用mocha有什么关系吗？

let inStream = fs.createReadStream("../files/bad.fasta").on('error', (err) => console.log(err));
let outStream = fs.createWriteStream("../files/bad_typed.fasta").on('error', (err) => console.log(err));