Fix infinite scroll on Operations and Activity pages

apps/desktop/src/components/AccountDrawer/AccountDrawerDisplay.test.tsx

@@ -51,6 +51,7 @@ beforeEach(() => {
     isFirstLoad: false,
     isLoading: false,
     loadMore: jest.fn(),
+    triggerRef: { current: null },
   });
   store.dispatch(networksActions.setCurrent(MAINNET));
   addTestAccount(store, selectedAccount);
@@ -300,6 +301,7 @@ describe("<AccountDrawerDisplay />", () => {
         isFirstLoad: false,
         isLoading: false,
         loadMore: jest.fn(),
+        triggerRef: { current: null },
       });
       multisigsFixture.forEach(account => addTestAccount(store, account));
     });

apps/desktop/src/setupTests.tsx

@@ -24,6 +24,22 @@ import {
 
 MockDate.set("2023-03-27T14:15:09.760Z");
 
+const mockIntersectionObserver = class MockIntersectionObserver {
+  callback: jest.Mock;
+  options: jest.Mock;
+  observe: jest.Mock;
+  unobserve: jest.Mock;
+  disconnect: jest.Mock;
+
+  constructor(callback: jest.Mock, options: jest.Mock) {
+    this.callback = callback;
+    this.options = options;
+    this.observe = jest.fn();
+    this.unobserve = jest.fn();
+    this.disconnect = jest.fn();
+  }
+};
+
 jest.mock("./env", () => ({ IS_DEV: false }));
 
 beforeEach(() => {
@@ -32,6 +48,7 @@ beforeEach(() => {
     crypto: { value: webcrypto, writable: true },
     TextDecoder: { value: TextDecoder, writable: true },
     TextEncoder: { value: TextEncoder, writable: true },
+    IntersectionObserver: { value: mockIntersectionObserver, writable: true, configurable: true },
     scrollTo: { value: jest.fn(), writable: true },
 
     // taken from https://jestjs.io/docs/manual-mocks#mocking-methods-which-are-not-implemented-in-jsdom

apps/desktop/src/views/operations/OperationsView.tsx

@@ -1,6 +1,5 @@
 import { Box, Center, Divider, Flex, Image } from "@chakra-ui/react";
 import { useGetOperations } from "@umami/data-polling";
-import { type UIEvent, useRef } from "react";
 
 import { NoOperations } from "../../components/NoItems";
 import { OperationTile, OperationTileContext } from "../../components/OperationTile";
@@ -10,26 +9,7 @@ import colors from "../../style/colors";
 
 export const OperationsView = () => {
   const { accountsFilter, selectedAccounts } = useAccountsFilter();
-  const { operations, loadMore, hasMore, isLoading, isFirstLoad } =
-    useGetOperations(selectedAccounts);
-  // used to run loadMore only once when the user scrolls to the bottom
-  // otherwise it might be called multiple times which would trigger multiple fetches
-  const skipLoadMore = useRef<boolean>(false);
-
-  const onScroll = (e: UIEvent<HTMLDivElement>) => {
-    if (skipLoadMore.current || !hasMore || isLoading) {
-      return;
-    }
-    const element = e.target as HTMLDivElement;
-
-    // start loading earlier than we reached the end of the list
-    if (element.scrollHeight - element.scrollTop - element.clientHeight < 100) {
-      skipLoadMore.current = true;
-      return loadMore().finally(() => {
-        skipLoadMore.current = false;
-      });
-    }
-  };
+  const { operations, isLoading, isFirstLoad, triggerRef } = useGetOperations(selectedAccounts);
 
   return (
     <Flex flexDirection="column" height="100%">
@@ -52,7 +32,6 @@ export const OperationsView = () => {
           marginBottom="20px"
           background={colors.gray[900]}
           borderRadius="8px"
-          onScroll={onScroll}
           paddingX="20px"
         >
           <OperationTileContext.Provider value={{ mode: "page" }}>
@@ -75,6 +54,7 @@ export const OperationsView = () => {
               );
             })}
           </OperationTileContext.Provider>
+          <Box ref={triggerRef} />
           <Center flexDirection="column" display={isLoading && !isFirstLoad ? "flex" : "none"}>
             <Divider />
             <Image width="100px" height="50px" src="./static/media/loading-dots.gif" />

apps/web/src/setupTests.ts

@@ -6,10 +6,21 @@ import { mockToast } from "@umami/state";
 import { mockLocalStorage } from "@umami/test-utils";
 import { setupJestCanvasMock } from "jest-canvas-mock";
 
-const intersectionObserverMock = () => ({
-  observe: jest.fn(),
-  unobserve: jest.fn(),
-});
+const mockIntersectionObserver = class MockIntersectionObserver {
+  callback: jest.Mock;
+  options: jest.Mock;
+  observe: jest.Mock;
+  unobserve: jest.Mock;
+  disconnect: jest.Mock;
+
+  constructor(callback: jest.Mock, options: jest.Mock) {
+    this.callback = callback;
+    this.options = options;
+    this.observe = jest.fn();
+    this.unobserve = jest.fn();
+    this.disconnect = jest.fn();
+  }
+};
 
 jest.mock("./env", () => ({ IS_DEV: false }));
 
@@ -23,7 +34,7 @@ Object.defineProperties(global, {
   crypto: { value: webcrypto, writable: true },
   TextDecoder: { value: TextDecoder, writable: true },
   TextEncoder: { value: TextEncoder, writable: true },
-  IntersectionObserver: { value: intersectionObserverMock, writable: true, configurable: true },
+  IntersectionObserver: { value: mockIntersectionObserver, writable: true, configurable: true },
 });
 
 jest.mock("./utils/persistor", () => ({

apps/web/src/views/Activity/Activity.tsx

@@ -2,7 +2,6 @@ import { Box, Center, Divider, Flex, Image, Spinner } from "@chakra-ui/react";
 import { type Account } from "@umami/core";
 import { useGetOperations } from "@umami/data-polling";
 import { useCurrentAccount } from "@umami/state";
-import { type UIEvent, useRef } from "react";
 
 import loadingDots from "../../assets/loading-dots.gif";
 import { EmptyMessage } from "../../components/EmptyMessage";
@@ -17,34 +16,15 @@ export const Activity = () => {
   const color = useColor();
   const currentAccount = useCurrentAccount();
 
-  const { operations, loadMore, hasMore, isLoading, isFirstLoad } = useGetOperations(
+  const { operations, isLoading, isFirstLoad, triggerRef } = useGetOperations(
     [currentAccount ?? ({} as Account)],
     isVerified
   );
 
   const buyTezUrl = `https://widget.wert.io/default/widget/?commodity=XTZ&address=${currentAccount?.address.pkh}&network=tezos&commodity_id=xtz.simple.tezos`;
 
-  // used to run loadMore only once when the user scrolls to the bottom
-  // otherwise it might be called multiple times which would trigger multiple fetches
-  const skipLoadMore = useRef<boolean>(false);
-
   const isEmpty = operations.length === 0 && !isLoading;
 
-  const onScroll = (e: UIEvent<HTMLDivElement>) => {
-    if (skipLoadMore.current || !hasMore || isLoading) {
-      return;
-    }
-    const element = e.target as HTMLDivElement;
-
-    // start loading earlier than we reached the end of the list
-    if (element.scrollHeight - element.scrollTop - element.clientHeight < 100) {
-      skipLoadMore.current = true;
-      return loadMore().finally(() => {
-        skipLoadMore.current = false;
-      });
-    }
-  };
-
   return (
     <>
       <Flex zIndex={1} flexDirection="column" flexGrow={1}>
@@ -68,7 +48,7 @@ export const Activity = () => {
           <VerifyMessage />
         )}
         {operations.length > 0 && (
-          <Box borderRadius="8px" onScroll={onScroll}>
+          <Box borderRadius="8px">
             {operations.map((operation, i) => {
               const isFirst = i === 0;
               const isLast = i === operations.length - 1;
@@ -84,6 +64,8 @@ export const Activity = () => {
                 />
               );
             })}
+            {/* trigger for loading more operations */}
+            <Box ref={triggerRef} />
             <Center flexDirection="column" display={isLoading && !isFirstLoad ? "flex" : "none"}>
               <Divider />
               <Image width="100px" height="50px" src={loadingDots} />

packages/data-polling/src/useGetOperations.tsx

@@ -16,7 +16,7 @@ import {
   getRelatedTokenTransfers,
 } from "@umami/tzkt";
 import { maxBy } from "lodash";
-import { useEffect } from "react";
+import { useEffect, useRef } from "react";
 
 import { useReactQueryErrorHandler } from "./useReactQueryErrorHandler";
 import { useRefetchTrigger } from "./useRefetchTrigger";
@@ -34,6 +34,7 @@ type UseGetOperationsResult = {
   isFirstLoad: boolean;
   isLoading: boolean;
   hasMore: boolean;
+  triggerRef: React.RefObject<HTMLDivElement>;
   loadMore: InfiniteQueryObserverBaseResult["fetchNextPage"];
 };
 
@@ -63,6 +64,8 @@ export const useGetOperations = (accounts: Account[], isEnabled = true): UseGetO
   const refetchTrigger = useRefetchTrigger();
   const handleError = useReactQueryErrorHandler();
 
+  const triggerRef = useRef<HTMLDivElement>(null);
+
   const {
     isFetching,
     data: operations,
@@ -128,12 +131,36 @@ export const useGetOperations = (accounts: Account[], isEnabled = true): UseGetO
     void fetchPreviousPage();
   }, [refetchTrigger, fetchPreviousPage, isEnabled]);
 
+  useEffect(() => {
+    if (!isEnabled || !triggerRef.current) {
+      return;
+    }
+
+    const observer = new IntersectionObserver(
+      entries => {
+        if (entries[0].isIntersecting && hasNextPage && !isLoading) {
+          void fetchNextPage();
+        }
+      },
+      {
+        root: null,
+        rootMargin: "100px",
+        threshold: 0,
+      }
+    );
+
+    observer.observe(triggerRef.current);
+
+    return () => observer.disconnect();
+  }, [hasNextPage, isLoading, fetchNextPage, isEnabled]);
+
   return {
+    hasMore: hasNextPage,
     operations: operations || [],
     isFirstLoad: isLoading,
     isLoading: isFetching,
-    hasMore: hasNextPage,
     loadMore: fetchNextPage,
+    triggerRef,
   };
 };