Revert "events: allow monitoring error events"

This reverts commit 5cb0de948dde157f007a1bbbd9337859112a5b0f.

3 files changed, 2 insertions, 69 deletions

diff --git a/doc/api/events.md b/doc/api/events.md
index dfa8189dbd..93939131a5 100644
--- a/doc/api/events.md
+++ b/doc/api/events.md
@@ -155,18 +155,6 @@ myEmitter.emit('error', new Error('whoops!'));
 // Prints: whoops! there was an error
 ```
 
-It is possible to monitor `'error'` events without consuming the emitted error
-by installing a listener using the symbol `errorMonitor`.
-
-```js
-const myEmitter = new MyEmitter();
-myEmitter.on(EventEmitter.errorMonitor, (err) => {
-  MyMonitoringTool.log(err);
-});
-myEmitter.emit('error', new Error('whoops!'));
-// Still throws and crashes Node.js
-```
-
 ## Capture Rejections of Promises
 
 > Stability: 1 - captureRejections is experimental.
@@ -360,19 +348,6 @@ the event emitter instance, the event’s name and the number of attached
 listeners, respectively.
 Its `name` property is set to `'MaxListenersExceededWarning'`.
 
-### `EventEmitter.errorMonitor`
-<!-- YAML
-added: v12.16.0
--->
-
-This symbol shall be used to install a listener for only monitoring `'error'`
-events. Listeners installed using this symbol are called before the regular
-`'error'` listeners are called.
-
-Installing a listener using this symbol does not change the behavior once an
-`'error'` event is emitted, therefore the process will still crash if no
-regular `'error'` listener is installed.
-
 ### `emitter.addListener(eventName, listener)`
 <!-- YAML
 added: v0.1.26
diff --git a/lib/events.js b/lib/events.js
index 76b376e789..62ed219172 100644
--- a/lib/events.js
+++ b/lib/events.js
@@ -60,7 +60,6 @@ const {
 } = require('internal/util/inspect');
 
 const kCapture = Symbol('kCapture');
-const kErrorMonitor = Symbol('events.errorMonitor');
 
 function EventEmitter(opts) {
   EventEmitter.init.call(this, opts);
@@ -90,13 +89,6 @@ ObjectDefineProperty(EventEmitter, 'captureRejections', {
   enumerable: true
 });
 
-ObjectDefineProperty(EventEmitter, 'errorMonitor', {
-  value: kErrorMonitor,
-  writable: false,
-  configurable: true,
-  enumerable: true
-});
-
 // The default for captureRejections is false
 ObjectDefineProperty(EventEmitter.prototype, kCapture, {
   value: false,
@@ -270,11 +262,9 @@ EventEmitter.prototype.emit = function emit(type, ...args) {
   let doError = (type === 'error');
 
   const events = this._events;
-  if (events !== undefined) {
-    if (doError && events[kErrorMonitor] !== undefined)
-      this.emit(kErrorMonitor, ...args);
+  if (events !== undefined)
     doError = (doError && events.error === undefined);
-  } else if (!doError)
+  else if (!doError)
     return false;
 
   // If there is no 'error' event listener then throw.
diff --git a/test/parallel/test-event-emitter-error-monitor.js b/test/parallel/test-event-emitter-error-monitor.js
deleted file mode 100644
index ba02839a84..0000000000
--- a/test/parallel/test-event-emitter-error-monitor.js
+++ /dev/null
@@ -1,32 +0,0 @@
-'use strict';
-const common = require('../common');
-const assert = require('assert');
-const EventEmitter = require('events');
-
-const EE = new EventEmitter();
-const theErr = new Error('MyError');
-
-EE.on(
-  EventEmitter.errorMonitor,
-  common.mustCall(function onErrorMonitor(e) {
-    assert.strictEqual(e, theErr);
-  }, 3)
-);
-
-// Verify with no error listener
-common.expectsError(
-  () => EE.emit('error', theErr), theErr
-);
-
-// Verify with error listener
-EE.once('error', common.mustCall((e) => assert.strictEqual(e, theErr)));
-EE.emit('error', theErr);
-
-
-// Verify it works with once
-process.nextTick(() => EE.emit('error', theErr));
-assert.rejects(EventEmitter.once(EE, 'notTriggered'), theErr);
-
-// Only error events trigger error monitor
-EE.on('aEvent', common.mustCall());
-EE.emit('aEvent');