fix(memo): preserve expanded todo list state

web/src/components/MemoContent/hooks.ts

@@ -2,17 +2,25 @@ import { useCallback, useEffect, useRef, useState } from "react";
 import { COMPACT_STATES, getMaxDisplayHeight } from "./constants";
 import type { ContentCompactView } from "./types";
 
-export const useCompactMode = (enabled: boolean) => {
+export const useCompactMode = (enabled: boolean, revision: string) => {
   const containerRef = useRef<HTMLDivElement>(null);
   const [mode, setMode] = useState<ContentCompactView | undefined>(undefined);
 
   useEffect(() => {
-    if (!enabled || !containerRef.current) return;
-    const maxHeight = getMaxDisplayHeight();
-    if (containerRef.current.getBoundingClientRect().height > maxHeight) {
-      setMode("ALL");
+    if (!enabled || !containerRef.current) {
+      setMode(undefined);
+      return;
     }
-  }, [enabled]);
+
+    const maxHeight = getMaxDisplayHeight();
+    const shouldCompact = Math.max(containerRef.current.scrollHeight, containerRef.current.getBoundingClientRect().height) > maxHeight;
+    setMode((currentMode) => {
+      if (!shouldCompact) {
+        return undefined;
+      }
+      return currentMode ?? "ALL";
+    });
+  }, [enabled, revision]);
 
   const toggle = useCallback(() => {
     if (!mode) return;

web/src/components/MemoContent/index.tsx

@@ -16,7 +16,7 @@ const MemoContent = (props: MemoContentProps) => {
     containerRef: memoContentContainerRef,
     mode: showCompactMode,
     toggle: toggleCompactMode,
-  } = useCompactMode(Boolean(props.compact));
+  } = useCompactMode(Boolean(props.compact), content);
   const mentionUsernames = useMemo(() => extractMentionUsernames(content), [content]);
   const resolvedMentionUsernames = useResolvedMentionUsernames(mentionUsernames);
 

web/src/components/MemoView/components/MemoBody.tsx

@@ -1,4 +1,3 @@
-import { useMemo } from "react";
 import { AttachmentListView, LocationDisplayView, RelationListView } from "@/components/MemoMetadata";
 import { cn } from "@/lib/utils";
 import { MemoRelation_Type } from "@/types/proto/api/v1/memo_service_pb";
@@ -23,22 +22,12 @@ const BlurOverlay: React.FC<{ onClick?: () => void }> = ({ onClick }) => {
   );
 };
 
-const getContentRevision = (content: string) => {
-  let hash = 2166136261;
-  for (let i = 0; i < content.length; i++) {
-    hash ^= content.charCodeAt(i);
-    hash = Math.imul(hash, 16777619);
-  }
-  return `${content.length}-${hash >>> 0}`;
-};
-
 const MemoBody: React.FC<MemoBodyProps> = ({ compact }) => {
   const { memo, parentPage, showBlurredContent, blurred, readonly, openEditor, openPreview, toggleBlurVisibility } = useMemoViewContext();
 
   const { handleMemoContentClick, handleMemoContentDoubleClick } = useMemoHandlers({ readonly, openEditor, openPreview });
 
   const referencedMemos = memo.relations.filter((relation) => relation.type === MemoRelation_Type.REFERENCE);
-  const contentRevision = useMemo(() => getContentRevision(memo.content), [memo.content]);
 
   return (
     <>
@@ -49,7 +38,7 @@ const MemoBody: React.FC<MemoBodyProps> = ({ compact }) => {
         )}
       >
         <MemoContent
-          key={`${memo.name}-${contentRevision}`}
+          key={memo.name}
           content={memo.content}
           onClick={handleMemoContentClick}
           onDoubleClick={handleMemoContentDoubleClick}

web/tests/memo-body-compact.test.tsx

@@ -0,0 +1,86 @@
+import { fireEvent, render, screen, waitFor } from "@testing-library/react";
+import { describe, expect, it, vi } from "vitest";
+import MemoBody from "@/components/MemoView/components/MemoBody";
+
+const mockState = vi.hoisted(() => ({
+  memo: {
+    name: "memos/1",
+    content: "",
+    relations: [],
+    attachments: [],
+    reactions: [],
+  },
+}));
+
+vi.mock("@/utils/i18n", () => ({
+  useTranslate: () => (key: string) => key,
+}));
+
+vi.mock("@/components/MemoContent/MentionResolutionContext", () => ({
+  useResolvedMentionUsernames: () => new Set<string>(),
+}));
+
+vi.mock("@/components/MemoContent/MemoMarkdownRenderer", () => ({
+  MemoMarkdownRenderer: ({ content }: { content: string }) => <div>{content}</div>,
+}));
+
+vi.mock("@/components/MemoMetadata", () => ({
+  AttachmentListView: () => null,
+  LocationDisplayView: () => null,
+  RelationListView: () => null,
+}));
+
+vi.mock("@/components/MemoReactionListView", () => ({
+  MemoReactionListView: () => null,
+}));
+
+vi.mock("@/components/MemoView/hooks", () => ({
+  useMemoHandlers: () => ({
+    handleMemoContentClick: vi.fn(),
+    handleMemoContentDoubleClick: vi.fn(),
+  }),
+}));
+
+vi.mock("@/components/MemoView/MemoViewContext", () => ({
+  useMemoViewContext: () => ({
+    memo: mockState.memo,
+    parentPage: "",
+    showBlurredContent: false,
+    blurred: false,
+    readonly: false,
+    openEditor: vi.fn(),
+    openPreview: vi.fn(),
+    toggleBlurVisibility: vi.fn(),
+  }),
+}));
+
+const createMemo = (content: string) => ({
+  name: "memos/1",
+  content,
+  relations: [],
+  attachments: [],
+  reactions: [],
+});
+
+describe("<MemoBody /> compact content", () => {
+  it("keeps expanded compact content expanded when memo content changes", async () => {
+    vi.spyOn(HTMLElement.prototype, "getBoundingClientRect").mockImplementation(function () {
+      if ((this as HTMLElement).hasAttribute("data-memo-content")) {
+        return { x: 0, y: 0, width: 320, height: 1000, top: 0, right: 320, bottom: 1000, left: 0, toJSON: () => ({}) };
+      }
+      return { x: 0, y: 0, width: 0, height: 0, top: 0, right: 0, bottom: 0, left: 0, toJSON: () => ({}) };
+    });
+
+    mockState.memo = createMemo("line 1\nline 2");
+    const { rerender } = render(<MemoBody compact={true} />);
+
+    await waitFor(() => expect(screen.getByRole("button", { name: /memo\.show-more/ })).toBeInTheDocument());
+    fireEvent.click(screen.getByRole("button", { name: /memo\.show-more/ }));
+    expect(screen.getByRole("button", { name: /memo\.show-less/ })).toBeInTheDocument();
+
+    mockState.memo = createMemo("line 1\nline 2 updated");
+    rerender(<MemoBody compact={true} />);
+
+    expect(screen.getByRole("button", { name: /memo\.show-less/ })).toBeInTheDocument();
+  });
+});