events: add/removeListener should call on/off

doc/api/events.md

@@ -290,8 +290,10 @@ added: v0.1.26
 -->
 * `eventName` {string|symbol}
 * `listener` {Function}
+* Returns: {EventEmitter}
 
-Alias for `emitter.on(eventName, listener)`.
+This function is implemented by calling [`emitter.on()`][].
+When overriding, override [`emitter.on()`][].
 
 ### emitter.emit(eventName[, ...args])
 <!-- YAML
@@ -415,7 +417,8 @@ added: v10.0.0
 * `listener` {Function}
 * Returns: {EventEmitter}
 
-Alias for [`emitter.removeListener()`][].
+This function is implemented by calling [`emitter.removeListener()`][].
+When overriding, override [`emitter.removeListener()`][].
 
 ### emitter.on(eventName, listener)
 <!-- YAML

lib/_http_server.js

@@ -421,7 +421,6 @@ function connectionListenerInternal(server, socket) {
 
  // Overrides to unconsume on `data`, `readable` listeners
  socket.on = generateSocketListenerWrapper('on');
- socket.addListener = generateSocketListenerWrapper('addListener');
  socket.prependListener = generateSocketListenerWrapper('prependListener');
 
  // We only consume the socket if it has never been consumed before.
@@ -792,7 +791,6 @@ function generateSocketListenerWrapper(originalFnName) {
  const res = net.Socket.prototype[originalFnName].call(this, ev, fn);
  if (!this.parser) {
  this.on = net.Socket.prototype.on;
- this.addListener = net.Socket.prototype.addListener;
  this.prependListener = net.Socket.prototype.prependListener;
  return res;
  }

lib/_stream_readable.js

@@ -897,7 +897,6 @@ Readable.prototype.on = function(ev, fn) {
 
  return res;
 };
-Readable.prototype.addListener = Readable.prototype.on;
 
 Readable.prototype.removeListener = function(ev, fn) {
  const res = Stream.prototype.removeListener.call(this, ev, fn);

lib/events.js

@@ -280,10 +280,12 @@ function _addListener(target, type, listener, prepend) {
 }
 
 EventEmitter.prototype.addListener = function addListener(type, listener) {
- return _addListener(this, type, listener, false);
+ return this.on(type, listener);
 };
 
-EventEmitter.prototype.on = EventEmitter.prototype.addListener;
+EventEmitter.prototype.on = function on(type, listener) {
+ return _addListener(this, type, listener, false);
+};
 
 EventEmitter.prototype.prependListener =
  function prependListener(type, listener) {
@@ -378,7 +380,10 @@ EventEmitter.prototype.removeListener =
  return this;
  };
 
-EventEmitter.prototype.off = EventEmitter.prototype.removeListener;
+EventEmitter.prototype.off =
+ function off(type, listener) {
+ return this.removeListener(type, listener);
+ };
 
 EventEmitter.prototype.removeAllListeners =
  function removeAllListeners(type) {

test/parallel/test-event-emitter-add-listeners.js

@@ -29,9 +29,6 @@ const EventEmitter = require('events');
  const events_new_listener_emitted = [];
  const listeners_new_listener_emitted = [];
 
- // Sanity check
- assert.strictEqual(ee.addListener, ee.on);
-
  ee.on('newListener', function(event, listener) {
  // Don't track newListener listeners.
  if (event === 'newListener')

test/parallel/test-event-emitter-method-names.js

@@ -26,10 +26,9 @@ const events = require('events');
 
 const E = events.EventEmitter.prototype;
 assert.strictEqual(E.constructor.name, 'EventEmitter');
-assert.strictEqual(E.on, E.addListener); // Same method.
-assert.strictEqual(E.off, E.removeListener); // Same method.
+
 Object.getOwnPropertyNames(E).forEach(function(name) {
- if (name === 'constructor' || name === 'on' || name === 'off') return;
+ if (name === 'constructor') return;
  if (typeof E[name] !== 'function') return;
  assert.strictEqual(E[name].name, name);
 });

test/parallel/test-events-override.js

@@ -0,0 +1,16 @@
+'use strict';
+
+const common = require('../common');
+const { EventEmitter: EE } = require('events');
+
+{
+ const e = new EE();
+ e.on = common.mustCall();
+ e.addListener('test', () => {});
+}
+
+{
+ const e = new EE();
+ e.removeListener = common.mustCall();
+ e.off('test', () => {});
+}