0.11: Writable stream does not emit 'finish' after a write()

[hueniverse]

var stream = require('stream');
var util = require('util');

var Peek = function () {
    stream.Writable.call(this);
};

util.inherits(Peek, stream.Writable);

Peek.prototype._write = function (chunk, encoding, callback) {
    callback();
};

var preview = new Peek();
preview.on('finish', function () {
    console.log('finish');
});

preview.write('some text', 'utf-8');
preview.end();
preview.removeAllListeners();

In node 0.10.17:

finish

in node 0.11.6:

Note that removing the preview.write() statement fixes the issue.

[isaacs]

This is actually a bugfix in master that didn't land in v0.10 because of a semantics change.

https://gist.github.com/isaacs/6359727

In v0.10, write() and end() callbacks might be called after the finish event was emitted. In your test, it actually is emitting finish, but it's waiting until the next tick, since a write() operation is still potentially pending completion.