From 7adf75f4901368a4c96582685679a67aa75f176d Mon Sep 17 00:00:00 2001
From: Noel De Martin <noel@moodle.com>
Date: Wed, 7 Feb 2024 14:25:52 +0100
Subject: [PATCH] MOBILE-4304 core: Improve infinite-loader race conditions

---
 .../infinite-loading/infinite-loading.ts      | 12 +++++------
 src/core/services/utils/utils.ts              | 20 ++++++++++++++++---
 2 files changed, 23 insertions(+), 9 deletions(-)

diff --git a/src/core/components/infinite-loading/infinite-loading.ts b/src/core/components/infinite-loading/infinite-loading.ts
index 87e2125b7..d1ed55b0d 100644
--- a/src/core/components/infinite-loading/infinite-loading.ts
+++ b/src/core/components/infinite-loading/infinite-loading.ts
@@ -69,17 +69,17 @@ export class CoreInfiniteLoadingComponent implements OnChanges {
             return;
         }
 
-        // Wait until next tick to allow items to render and scroll content to grow.
-        await CoreUtils.nextTick();
+        const scrollElement = await this.hostElement.closest('ion-content')?.getScrollElement();
 
-        // Calculate distance from edge.
-        const content = this.hostElement.closest('ion-content');
-        if (!content) {
+        if (!scrollElement) {
             return;
         }
 
-        const scrollElement = await content.getScrollElement();
+        // Wait to allow items to render and scroll content to grow.
+        await CoreUtils.nextTick();
+        await CoreUtils.waitFor(() => scrollElement.scrollHeight > scrollElement.clientHeight, { timeout: 1000 });
 
+        // Calculate distance from edge.
         const infiniteHeight = this.hostElement.getBoundingClientRect().height;
         const scrollTop = scrollElement.scrollTop;
         const height = scrollElement.offsetHeight;
diff --git a/src/core/services/utils/utils.ts b/src/core/services/utils/utils.ts
index 7b806af80..312dc74d3 100644
--- a/src/core/services/utils/utils.ts
+++ b/src/core/services/utils/utils.ts
@@ -1826,23 +1826,29 @@ export class CoreUtilsProvider {
      * @param condition Condition.
      * @returns Cancellable promise.
      */
-    waitFor(condition: () => boolean, interval: number = 50): CoreCancellablePromise<void> {
+    waitFor(condition: () => boolean): CoreCancellablePromise<void>;
+    waitFor(condition: () => boolean, options: CoreUtilsWaitOptions): CoreCancellablePromise<void>;
+    waitFor(condition: () => boolean, interval: number): CoreCancellablePromise<void>;
+    waitFor(condition: () => boolean, optionsOrInterval: CoreUtilsWaitOptions | number = {}): CoreCancellablePromise<void> {
+        const options = typeof optionsOrInterval === 'number' ? { interval: optionsOrInterval } : optionsOrInterval;
+
         if (condition()) {
             return CoreCancellablePromise.resolve();
         }
 
+        const startTime = Date.now();
         let intervalId: number | undefined;
 
         return new CoreCancellablePromise<void>(
             async (resolve) => {
                 intervalId = window.setInterval(() => {
-                    if (!condition()) {
+                    if (!condition() && (!options.timeout || (Date.now() - startTime < options.timeout))) {
                         return;
                     }
 
                     resolve();
                     window.clearInterval(intervalId);
-                }, interval);
+                }, options.interval ?? 50);
             },
             () => window.clearInterval(intervalId),
         );
@@ -1939,6 +1945,14 @@ export type CoreUtilsOpenInAppOptions = InAppBrowserOptions & {
     originalUrl?: string; // Original URL to open (in case the URL was treated, e.g. to add a token or an auto-login).
 };
 
+/**
+ * Options for waiting.
+ */
+export type CoreUtilsWaitOptions = {
+    interval?: number;
+    timeout?: number;
+};
+
 /**
  * Possible default picker actions.
  */