mirror of https://github.com/lukechilds/node.git
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
47 lines
1.1 KiB
47 lines
1.1 KiB
'use strict';
|
|
|
|
const common = require('../common');
|
|
const EventEmitter = require('events');
|
|
const assert = require('assert');
|
|
|
|
const myEE = new EventEmitter();
|
|
var m = 0;
|
|
// This one comes last.
|
|
myEE.on('foo', common.mustCall(() => assert.equal(m, 2)));
|
|
|
|
// This one comes second.
|
|
myEE.prependListener('foo', common.mustCall(() => assert.equal(m++, 1)));
|
|
|
|
// This one comes first.
|
|
myEE.prependOnceListener('foo', common.mustCall(() => assert.equal(m++, 0)));
|
|
|
|
myEE.emit('foo');
|
|
|
|
// Verify that the listener must be a function
|
|
assert.throws(() => {
|
|
const ee = new EventEmitter();
|
|
|
|
ee.prependOnceListener('foo', null);
|
|
}, /^TypeError: "listener" argument must be a function$/);
|
|
|
|
// Test fallback if prependListener is undefined.
|
|
const stream = require('stream');
|
|
const util = require('util');
|
|
|
|
delete EventEmitter.prototype.prependListener;
|
|
|
|
function Writable() {
|
|
this.writable = true;
|
|
stream.Stream.call(this);
|
|
}
|
|
util.inherits(Writable, stream.Stream);
|
|
|
|
function Readable() {
|
|
this.readable = true;
|
|
stream.Stream.call(this);
|
|
}
|
|
util.inherits(Readable, stream.Stream);
|
|
|
|
const w = new Writable();
|
|
const r = new Readable();
|
|
r.pipe(w);
|
|
|