feat(event-listeners-manager): easy way to clean up event listeners

@vates/event-listeners-manager/.USAGE.md

@@ -0,0 +1,50 @@
+> This library is compatible with Node's `EventEmitter` and web browsers' `EventTarget` APIs.
+
+### API
+
+```js
+import { EventListenersManager } from '@vates/event-listeners-manager'
+
+const events = new EventListenersManager(emitter)
+
+// adding listeners
+events.add('foo', onFoo).add('bar', onBar).on('baz', onBaz)
+
+// removing a specific listener
+events.remove('foo', onFoo)
+
+// removing all listeners for a specific event
+events.removeAll('foo')
+
+// removing all listeners
+events.removeAll()
+```
+
+### Typical use case
+
+> Removing all listeners when no longer necessary.
+
+Manually:
+
+```js
+const onFoo = () => {}
+const onBar = () => {}
+const onBaz = () => {}
+emitter.on('foo', onFoo).on('bar', onBar).on('baz', onBaz)
+
+// CODE LOGIC
+
+emitter.off('foo', onFoo).off('bar', onBar).off('baz', onBaz)
+```
+
+With this library:
+
+```js
+const events = new EventListenersManager(emitter)
+
+events.add('foo', () => {})).add('bar', () => {})).add('baz', () => {}))
+
+// CODE LOGIC
+
+events.removeAll()
+```

@vates/event-listeners-manager/.npmignore

@@ -0,0 +1 @@
+../../scripts/npmignore

@vates/event-listeners-manager/README.md

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+<!-- DO NOT EDIT MANUALLY, THIS FILE HAS BEEN GENERATED -->
+
+# @vates/event-listeners-manager
+
+[![Package Version](https://badgen.net/npm/v/@vates/event-listeners-manager)](https://npmjs.org/package/@vates/event-listeners-manager) ![License](https://badgen.net/npm/license/@vates/event-listeners-manager) [![PackagePhobia](https://badgen.net/bundlephobia/minzip/@vates/event-listeners-manager)](https://bundlephobia.com/result?p=@vates/event-listeners-manager) [![Node compatibility](https://badgen.net/npm/node/@vates/event-listeners-manager)](https://npmjs.org/package/@vates/event-listeners-manager)
+
+## Install
+
+Installation of the [npm package](https://npmjs.org/package/@vates/event-listeners-manager):
+
+```
+> npm install --save @vates/event-listeners-manager
+```
+
+## Usage
+
+> This library is compatible with Node's `EventEmitter` and web browsers' `EventTarget` APIs.
+
+### API
+
+```js
+import { EventListenersManager } from '@vates/event-listeners-manager'
+
+const events = new EventListenersManager(emitter)
+
+// adding listeners
+events.add('foo', onFoo).add('bar', onBar).on('baz', onBaz)
+
+// removing a specific listener
+events.remove('foo', onFoo)
+
+// removing all listeners for a specific event
+events.removeAll('foo')
+
+// removing all listeners
+events.removeAll()
+```
+
+### Typical use case
+
+> Removing all listeners when no longer necessary.
+
+Manually:
+
+```js
+const onFoo = () => {}
+const onBar = () => {}
+const onBaz = () => {}
+emitter.on('foo', onFoo).on('bar', onBar).on('baz', onBaz)
+
+// CODE LOGIC
+
+emitter.off('foo', onFoo).off('bar', onBar).off('baz', onBaz)
+```
+
+With this library:
+
+```js
+const events = new EventListenersManager(emitter)
+
+events.add('foo', () => {})).add('bar', () => {})).add('baz', () => {}))
+
+// CODE LOGIC
+
+events.removeAll()
+```
+
+## Contributions
+
+Contributions are _very_ welcomed, either on the documentation or on
+the code.
+
+You may:
+
+- report any [issue](https://github.com/vatesfr/xen-orchestra/issues)
+  you've encountered;
+- fork and create a pull request.
+
+## License
+
+[ISC](https://spdx.org/licenses/ISC) © [Vates SAS](https://vates.fr)

@vates/event-listeners-manager/index.js

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+'use strict'
+
+exports.EventListenersManager = class EventListenersManager {
+  constructor(emitter) {
+    this._listeners = new Map()
+
+    this._add = (emitter.addListener || emitter.addEventListener).bind(emitter)
+    this._remove = (emitter.removeListener || emitter.removeEventListener).bind(emitter)
+  }
+
+  add(type, listener) {
+    let listeners = this._listeners[type]
+    if (listeners === undefined) {
+      listeners = new Set()
+      this._listeners.set(type, listeners)
+    }
+
+    // don't add the same listener multiple times (allowed on Node.js)
+    if (!listeners.has(listener)) {
+      listeners.add(listener)
+      this._add(type, listener)
+    }
+
+    return this
+  }
+
+  remove(type, listener) {
+    const allListeners = this._listeners
+    const listeners = allListeners.get(type)
+    if (listeners !== undefined && listeners.delete(listener)) {
+      this._remove(type, listener)
+      if (listeners.size === 0) {
+        allListeners.delete(type)
+      }
+    }
+
+    return this
+  }
+
+  removeAll(type) {
+    const allListeners = this._listeners
+    const remove = this._remove
+    const types = type !== undefined ? [type] : allListeners.keys()
+    for (const type of types) {
+      const listeners = allListeners.get(type)
+      if (listeners !== undefined) {
+        allListeners.delete(type)
+        for (const listener of listeners) {
+          remove(type, listener)
+        }
+      }
+    }
+
+    return this
+  }
+}

@vates/event-listeners-manager/package.json

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+{
+  "engines": {
+    "node": ">=6"
+  },
+  "private": false,
+  "name": "@vates/event-listeners-manager",
+  "descriptions": "Easy way to clean up event listeners",
+  "keywords": [
+    "add",
+    "addEventListener",
+    "addListener",
+    "browser",
+    "clear",
+    "DOM",
+    "emitter",
+    "event",
+    "EventEmitter",
+    "EventTarget",
+    "management",
+    "manager",
+    "node",
+    "remove",
+    "removeEventListener",
+    "removeListener"
+  ],
+  "homepage": "https://github.com/vatesfr/xen-orchestra/tree/master/@vates/event-listeners-manager",
+  "bugs": "https://github.com/vatesfr/xen-orchestra/issues",
+  "repository": {
+    "directory": "@vates/event-listeners-manager",
+    "type": "git",
+    "url": "https://github.com/vatesfr/xen-orchestra.git"
+  },
+  "author": {
+    "name": "Vates SAS",
+    "url": "https://vates.fr"
+  },
+  "license": "ISC",
+  "version": "0.0.0",
+  "scripts": {
+    "postversion": "npm publish --access public"
+  }
+}

CHANGELOG.unreleased.md

@@ -31,6 +31,7 @@
 >
 > In case of conflict, the highest (lowest in previous list) `$version` wins.
 
+- @vates/event-listeners-manager major
 - xo-vmdk-to-vhd minor
 - xo-server minor
 - xo-web minor