Unbind global listeners after the map is removed (patch) (#1434)

* fix global keyboard and window listeners are not removed after the map is destroyed

* test: add a test case for keyboard mixin

* change `map.on` to `map.once` & extract keyboard event listener unbind function

Co-authored-by: Florian Bischof <design.falke@gmail.com>

* fix missing dot operator

* tweak the mixins test case

Co-authored-by: Florian Bischof <design.falke@gmail.com>

* Fix test naming

---------

Co-authored-by: Florian Bischof <design.falke@gmail.com>

Author: plainheart

cypress/integration/mixins.spec.js

@@ -0,0 +1,25 @@
+describe('KeyboardMixin', () => {
+  it('Should unbind event listeners that bound by the KeyboardMixin after the map is destroyed', () => {
+    cy.window().then((window) => {
+      const { map, document } = window;
+
+      map.remove();
+
+      const isWindowBlurEventUnbound = !Object.entries(
+        window._leaflet_events
+      ).some(([name, handler]) => name.startsWith('blur') && handler);
+      expect(
+        isWindowBlurEventUnbound,
+        'window blur event listener is not unbound'
+      ).to.eq(true);
+
+      const isKeyUpDownEventUnbound = !Object.entries(
+        document._leaflet_events
+      ).some(([name, handler]) => name.startsWith('key') && handler);
+      expect(
+        isKeyUpDownEventUnbound,
+        'document keyboard event listener is not unbound'
+      ).to.eq(true);
+    });
+  });
+});

src/js/L.PM.Map.js

@@ -5,7 +5,7 @@ import GlobalDragMode from './Mixins/Modes/Mode.Drag';
 import GlobalRemovalMode from './Mixins/Modes/Mode.Removal';
 import GlobalRotateMode from './Mixins/Modes/Mode.Rotate';
 import EventMixin from './Mixins/Events';
-import KeyboardMixins from './Mixins/Keyboard';
+import createKeyboardMixins from './Mixins/Keyboard';
 import { getRenderer } from './helpers';
 
 const Map = L.Class.extend({
@@ -20,7 +20,7 @@ const Map = L.Class.extend({
     this.map = map;
     this.Draw = new L.PM.Draw(map);
     this.Toolbar = new L.PM.Toolbar(map);
-    this.Keyboard = KeyboardMixins;
+    this.Keyboard = createKeyboardMixins();
 
     this.globalOptions = {
       snappable: true,

src/js/Mixins/Keyboard.js

@@ -1,9 +1,17 @@
-const KeyboardMixins = {
+// use function to create a new mixin object for keeping isolation
+// to make it work for multiple map instances
+const createKeyboardMixins = () => ({
   _lastEvents: { keydown: undefined, keyup: undefined, current: undefined },
   _initKeyListener(map) {
     this.map = map;
     L.DomEvent.on(document, 'keydown keyup', this._onKeyListener, this);
     L.DomEvent.on(window, 'blur', this._onBlur, this);
+    // clean up global listeners when current map instance is destroyed
+    map.once('unload', this._unbindKeyListenerEvents, this);
+  },
+  _unbindKeyListenerEvents() {
+      L.DomEvent.off(document, 'keydown keyup', this._onKeyListener, this);
+      L.DomEvent.off(window, 'blur', this._onBlur, this);
   },
   _onKeyListener(e) {
     let focusOn = 'document';
@@ -44,6 +52,6 @@ const KeyboardMixins = {
   getPressedKey() {
     return this._lastEvents.current?.event.key;
   },
-};
+});
 
-export default KeyboardMixins;
+export default createKeyboardMixins;