DEV: Don't nest deferring calls (#30449)

Each case simplified:

`next(() => later(() => ...))` -> "wait 0 ms then wait X ms"
`next(() => debounce(() => ...))` -> "wait 0 ms then wait X ms
(debounced)"
`next(() => scheduleAfter("render", ...))` -> "in the next (empty) run
loop, do the thing (after a no-op render step)"

app/assets/javascripts/discourse/app/components/composer-editor.js

@@ -1,7 +1,7 @@
 import Component from "@ember/component";
 import EmberObject, { action, computed } from "@ember/object";
 import { getOwner } from "@ember/owner";
-import { next, schedule, throttle } from "@ember/runloop";
+import { schedule, throttle } from "@ember/runloop";
 import { service } from "@ember/service";
 import { classNameBindings } from "@ember-decorators/component";
 import { observes, on } from "@ember-decorators/object";
@@ -803,13 +803,11 @@ export default class ComposerEditor extends Component {
 
     this.appEvents.trigger(`${this.composerEventPrefix}:will-close`);
 
-    next(() => {
-      // need to wait a bit for the "slide down" transition of the composer
-      discourseLater(
-        () => this.appEvents.trigger(`${this.composerEventPrefix}:closed`),
-        400
-      );
-    });
+    // need to wait a bit for the "slide down" transition of the composer
+    discourseLater(
+      () => this.appEvents.trigger(`${this.composerEventPrefix}:closed`),
+      400
+    );
 
     preview?.removeEventListener("click", this._handleAltTextCancelButtonClick);
     preview?.removeEventListener("click", this._handleAltTextEditButtonClick);

app/assets/javascripts/discourse/app/services/route-scroll-manager.js

@@ -1,4 +1,4 @@
-import { next, schedule } from "@ember/runloop";
+import { next } from "@ember/runloop";
 import Service, { service } from "@ember/service";
 import { bind } from "discourse/lib/decorators";
 import { isTesting } from "discourse/lib/environment";
@@ -55,11 +55,7 @@ export default class RouteScrollManager extends Service {
 
     const scrollLocation = this.historyStore.get(STORE_KEY) || [0, 0];
 
-    next(() =>
-      schedule("afterRender", () =>
-        this.scrollElement.scrollTo(...scrollLocation)
-      )
-    );
+    next(() => this.scrollElement.scrollTo(...scrollLocation));
   }
 
   #shouldScroll(routeInfo) {

app/assets/javascripts/discourse/app/services/scroll-direction.js

@@ -1,5 +1,5 @@
 import { tracked } from "@glimmer/tracking";
-import { next, throttle } from "@ember/runloop";
+import { throttle } from "@ember/runloop";
 import Service, { service } from "@ember/service";
 import discourseDebounce from "discourse/lib/debounce";
 import { bind } from "discourse/lib/decorators";
@@ -49,11 +49,8 @@ export default class ScrollDirection extends Service {
     // User hasn't scrolled yet on this route
     this.lastScrollDirection = UNSCROLLED;
 
-    // Wait for the initial DOM render to be done
-    next(() => {
-      // Then allow a bit of extra time for any DOM shifts to settle
-      discourseDebounce(this.unpause, PAUSE_AFTER_TRANSITION_MS);
-    });
+    // Allow a bit of extra time for any DOM shifts to settle
+    discourseDebounce(this.unpause, PAUSE_AFTER_TRANSITION_MS);
   }
 
   @bind

app/assets/javascripts/select-kit/addon/components/select-kit.js

@@ -1,7 +1,7 @@
 import Component from "@ember/component";
 import EmberObject, { computed, get } from "@ember/object";
 import { guidFor } from "@ember/object/internals";
-import { bind, cancel, next, schedule, throttle } from "@ember/runloop";
+import { bind, cancel, next, throttle } from "@ember/runloop";
 import { service } from "@ember/service";
 import { isEmpty, isNone, isPresent } from "@ember/utils";
 import {
@@ -760,13 +760,11 @@ export default class SelectKit extends Component.extend(UtilsMixin) {
 
   _safeAfterRender(fn) {
     next(() => {
-      schedule("afterRender", () => {
-        if (!this.element || this.isDestroyed || this.isDestroying) {
-          return;
-        }
+      if (!this.element || this.isDestroyed || this.isDestroying) {
+        return;
+      }
 
-        fn();
-      });
+      fn();
     });
   }
 

plugins/chat/assets/javascripts/discourse/lib/textarea-interactor.js

@@ -49,37 +49,33 @@ export default class TextareaInteractor extends EmberObject {
   @bind
   blur() {
     next(() => {
-      schedule("afterRender", () => {
-        this.textarea.blur();
-      });
+      this.textarea.blur();
     });
   }
 
   @bind
   focus(opts = { ensureAtEnd: false, refreshHeight: true, addText: null }) {
     next(() => {
-      schedule("afterRender", () => {
-        if (opts.refreshHeight) {
-          this.refreshHeight();
-        }
+      if (opts.refreshHeight) {
+        this.refreshHeight();
+      }
 
-        if (opts.ensureAtEnd) {
-          this.ensureCaretAtEnd();
-        }
+      if (opts.ensureAtEnd) {
+        this.ensureCaretAtEnd();
+      }
 
-        if (this.capabilities.isIpadOS || this.site.mobileView) {
-          return;
-        }
+      if (this.capabilities.isIpadOS || this.site.mobileView) {
+        return;
+      }
 
-        if (opts.addText) {
-          this.textManipulation.addText(
-            this.textManipulation.getSelected(),
-            opts.addText
-          );
-        }
+      if (opts.addText) {
+        this.textManipulation.addText(
+          this.textManipulation.getSelected(),
+          opts.addText
+        );
+      }
 
-        this.textManipulation.blurAndFocus();
-      });
+      this.textManipulation.blurAndFocus();
     });
   }