fix(debouncing): (backport from Qv2) cancel pending debounced calls when components are destroyed (quasarframework#11607)

Author: pdanpdan

ui/src/components/infinite-scroll/QInfiniteScroll.js

@@ -139,6 +139,7 @@ export default Vue.extend({
         this.working = false
         this.fetching = false
         this.__scrollTarget.removeEventListener('scroll', this.poll, passive)
+        typeof this.poll.cancel === 'function' && this.poll.cancel()
       }
     },
 

ui/src/components/parallax/QParallax.js

@@ -103,6 +103,9 @@ export default Vue.extend({
     __stop () {
       if (this.working === true) {
         this.working = false
+        this.__setPos.cancel()
+        this.__update.cancel()
+        this.__resizeHandler.cancel()
         this.__scrollTarget.removeEventListener('scroll', this.__updatePos, passive)
         window.removeEventListener('resize', this.__resizeHandler, passive)
         this.__scrollTarget = void 0

ui/src/components/scroll-area/QScrollArea.js

@@ -336,5 +336,9 @@ export default Vue.extend({
         this.$emit('scroll', info)
       }
     }, 0)
+  },
+
+  beforeDestroy () {
+    this.__emitScroll.cancel()
   }
 })

ui/src/directives/ScrollFire.js

@@ -20,6 +20,7 @@ function destroy (el) {
   const ctx = el.__qscrollfire
   if (ctx !== void 0) {
     ctx.scrollTarget.removeEventListener('scroll', ctx.scroll, listenOpts.passive)
+    ctx.scroll.cancel()
     delete el.__qscrollfire
   }
 }

ui/src/mixins/virtual-scroll.js

@@ -730,6 +730,7 @@ export default {
   },
 
   beforeDestroy () {
+    this.__onVirtualScrollEvt.cancel()
     const styleSheet = document.getElementById(this.id + '_ss')
     styleSheet !== null && styleSheet.remove()
   }