stream: improve multiple callback error message

When a transform stream's callback is called more than once,
an error is emitted with a somewhat confusing message. This
commit hopes to improve the quality of the error message.

Fixes: https://github.com/nodejs/node/issues/12513
PR-URL: https://github.com/nodejs/node/pull/12520
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
This commit is contained in:
cjihrig 2017-04-19 15:01:43 -04:00
parent ad4765a326
commit f8c617dbe2
2 changed files with 18 additions and 2 deletions

View File

@ -88,8 +88,10 @@ function afterTransform(stream, er, data) {
var cb = ts.writecb;
if (!cb)
return stream.emit('error', new Error('no writecb in Transform class'));
if (!cb) {
return stream.emit('error',
new Error('write callback called multiple times'));
}
ts.writechunk = null;
ts.writecb = null;

View File

@ -0,0 +1,14 @@
'use strict';
const common = require('../common');
const assert = require('assert');
const { Transform } = require('stream');
const stream = new Transform({
transform(chunk, enc, cb) { cb(); cb(); }
});
stream.on('error', common.mustCall((err) => {
assert.strictEqual(err.toString(),
'Error: write callback called multiple times');
}));
stream.write('foo');