fix(mobile): preserve social timeline scroll reset

Author: DIYgod

apps/mobile/src/modules/entry-list/EntryListContentSocial.tsx

@@ -11,6 +11,7 @@ import { View } from "react-native"
 import { useActionLanguage, useGeneralSettingKey } from "@/src/atoms/settings/general"
 
 import { useEntries } from "../screen/atoms"
+import { getResetScrollSignalForContent } from "../screen/scroll-reset"
 import { TimelineSelectorList } from "../screen/TimelineSelectorList"
 import { EntryListEndScrollSpacer } from "./EntryListEndScrollSpacer"
 import { EntryListFooter } from "./EntryListFooter"
@@ -92,14 +93,21 @@ export const EntryListContentSocial = ({
     mode: translationMode,
   })
 
+  const contentResetScrollSignal = getResetScrollSignalForContent({
+    entryCount: entryIds?.length ?? 0,
+    hasScrollableSkeleton: true,
+    isReady,
+    resetScrollSignal,
+  })
+
   // Show loading skeleton when entries are not ready and no data yet
   if (!isReady && (!entryIds || entryIds.length === 0)) {
     return (
       <TimelineSelectorList
         onRefresh={() => {}}
         isRefetching={false}
         onResetScrollSignalConsumed={onResetScrollSignalConsumed}
-        resetScrollSignal={resetScrollSignal}
+        resetScrollSignal={contentResetScrollSignal}
         data={Array.from({ length: 5 }).map((_, index) => `skeleton-${index}`)}
         keyExtractor={(id) => id}
         renderItem={EntryItemSkeleton}
@@ -116,7 +124,7 @@ export const EntryListContentSocial = ({
       }}
       isRefetching={isRefetching}
       onResetScrollSignalConsumed={onResetScrollSignalConsumed}
-      resetScrollSignal={resetScrollSignal}
+      resetScrollSignal={contentResetScrollSignal}
       data={entryIds}
       extraData={extraData}
       keyExtractor={(id) => id}

apps/mobile/src/modules/screen/scroll-reset.test.ts

@@ -1,6 +1,10 @@
 import { describe, expect, test } from "vitest"
 
-import { shouldApplyScrollResetSignal, shouldSuspendMarkReadForScrollReset } from "./scroll-reset"
+import {
+  getResetScrollSignalForContent,
+  shouldApplyScrollResetSignal,
+  shouldSuspendMarkReadForScrollReset,
+} from "./scroll-reset"
 
 describe("shouldApplyScrollResetSignal", () => {
   test("applies a new reset signal that has not been flushed yet", () => {
@@ -34,4 +38,24 @@ describe("shouldApplyScrollResetSignal", () => {
       }),
     ).toBe(false)
   })
+
+  test("does not forward reset signal to scrollable loading skeletons", () => {
+    expect(
+      getResetScrollSignalForContent({
+        entryCount: 0,
+        hasScrollableSkeleton: true,
+        isReady: false,
+        resetScrollSignal: 1,
+      }),
+    ).toBeUndefined()
+
+    expect(
+      getResetScrollSignalForContent({
+        entryCount: 1,
+        hasScrollableSkeleton: true,
+        isReady: true,
+        resetScrollSignal: 1,
+      }),
+    ).toBe(1)
+  })
 })

apps/mobile/src/modules/screen/scroll-reset.ts

@@ -9,3 +9,15 @@ export const shouldApplyScrollResetSignal = ({
 }: ScrollResetSignalState) => resetSignal !== undefined && resetSignal !== appliedResetSignal
 
 export const shouldSuspendMarkReadForScrollReset = shouldApplyScrollResetSignal
+
+export const getResetScrollSignalForContent = ({
+  entryCount,
+  hasScrollableSkeleton,
+  isReady,
+  resetScrollSignal,
+}: {
+  entryCount: number
+  hasScrollableSkeleton: boolean
+  isReady: boolean
+  resetScrollSignal?: number
+}) => (!isReady && entryCount === 0 && hasScrollableSkeleton ? undefined : resetScrollSignal)