fix: keep yearbook stable during month navigation

app/game-frontend/src/views/YearbookView.vue

@@ -35,6 +35,7 @@ const history = ref<HistoryData | null>(null);
 const selectedYearMonth = ref<number | null>(null);
 const settingsOpen = ref(false);
 const rankingBottom = ref(localStorage.getItem('yearbook-ranking-bottom') === 'true');
+let historyRequestId = 0;
 const serverID = computed(() => {
     const value = route.query.serverID;
     const raw = Array.isArray(value) ? value[0] : value;
@@ -71,19 +72,27 @@ const loadHistory = async (): Promise<void> => {
     if (selectedYearMonth.value === null) {
         return;
     }
+    const requestId = ++historyRequestId;
     loading.value = true;
     errorMessage.value = '';
     try {
         const { year, month } = parseYearMonth(selectedYearMonth.value);
         const result = await trpc.yearbook.getHistory.query({ year, month, serverID: serverID.value });
+        if (requestId !== historyRequestId) {
+            return;
+        }
         if ('data' in result) {
             history.value = result.data;
         }
     } catch (error) {
-        history.value = null;
+        if (requestId !== historyRequestId) {
+            return;
+        }
         errorMessage.value = error instanceof Error ? error.message : '연감 데이터를 불러오지 못했습니다.';
     } finally {
-        loading.value = false;
+        if (requestId === historyRequestId) {
+            loading.value = false;
+        }
     }
 };
 
@@ -129,7 +138,13 @@ onMounted(async () => {
             <strong>연 감</strong>
             <button class="legacy-button close-button" type="button" @click="closePage">창 닫기</button>
             <span class="settings-menu">
-                <button class="legacy-button legacy-button--navigation" type="button" @click="settingsOpen = !settingsOpen">⚙ 설정⌄</button>
+                <button
+                    class="legacy-button legacy-button--navigation"
+                    type="button"
+                    @click="settingsOpen = !settingsOpen"
+                >
+                    ⚙ 설정⌄
+                </button>
                 <button v-if="settingsOpen" class="settings-item" type="button" @click="toggleRankingPosition">
                     국가 순서 위치 변경(모바일 전용)
                 </button>
@@ -164,9 +179,9 @@ onMounted(async () => {
         <div v-if="errorMessage" class="yearbook-message error" role="alert">{{ errorMessage }}</div>
         <div v-else-if="loading && !history" class="yearbook-message">불러오는 중...</div>
 
-        <section v-if="history" :class="['history-grid', { 'ranking-bottom': rankingBottom }]">
+        <section v-if="history" :class="['history-grid', { 'ranking-bottom': rankingBottom }]" :aria-busy="loading">
             <div class="map-position">
-                <MapViewer :map-data="history.map" :map-layout="mapLayout" :loading="loading" />
+                <MapViewer :map-data="history.map" :map-layout="mapLayout" :loading="loading && !history" />
             </div>
             <aside class="nation-position">
                 <table>

tools/frontend-legacy-parity/fixtures/canonical.ts

@@ -232,8 +232,24 @@ export const canonicalFrontendFixture = {
                     ],
                 },
                 nations: [
-                    { id: 1, name: '한', color: '#d32f2f', level: 5, power: 1250, cities: ['낙양', '업'] },
+                    {
-                    { id: 2, name: '진', color: '#1976d2', level: 4, power: 980, cities: ['장안'] },
+                        id: 1,
+                        name: '한',
+                        color: '#d32f2f',
+                        level: 5,
+                        power: 1250,
+                        generalCount: 12,
+                        cities: ['낙양', '업'],
+                    },
+                    {
+                        id: 2,
+                        name: '진',
+                        color: '#1976d2',
+                        level: 4,
+                        power: 980,
+                        generalCount: 8,
+                        cities: ['장안'],
+                    },
                 ],
                 globalHistory: ['<C>●</> 한이 낙양을 지키고 있습니다.'],
                 globalAction: ['<L>●</> 유비가 내정을 수행했습니다.'],

tools/frontend-legacy-parity/visual-parity.spec.ts

@@ -971,6 +971,108 @@ test.describe('yearbook legacy parity', () => {
         await expect(page.getByRole('alert')).toBeVisible();
         await expect(page.getByLabel('연월 선택')).toBeVisible();
     });
+
+    test('keeps the rendered yearbook in place while moving between months', async ({ page }) => {
+        await page.goto(gameUrl('/yearbook'));
+        await expect(page.getByText('한이 낙양을 지키고 있습니다.')).toBeVisible();
+
+        let releaseHistory: (() => void) | undefined;
+        const historyReleased = new Promise<void>((resolve) => {
+            releaseHistory = resolve;
+        });
+        let markHistoryRequested: (() => void) | undefined;
+        const historyRequested = new Promise<void>((resolve) => {
+            markHistoryRequested = resolve;
+        });
+        await page.route('**/che/api/trpc/**', async (route) => {
+            if (!operationNames(route).includes('yearbook.getHistory')) {
+                await route.fallback();
+                return;
+            }
+            markHistoryRequested?.();
+            await historyReleased;
+            await fulfillOperations(route, () => ({
+                notModified: false,
+                hash: 'yearbook-previous-month-hash',
+                data: {
+                    ...fixture.game.yearbook.data,
+                    year: 197,
+                    month: 6,
+                    map: {
+                        ...fixture.game.yearbook.data.map,
+                        year: 197,
+                        month: 6,
+                    },
+                    nations: fixture.game.yearbook.data.nations.map((nation, index) => ({
+                        ...nation,
+                        generalCount: index === 0 ? 12 : 8,
+                    })),
+                    globalHistory: ['<C>●</> 이전 달의 중원 정세입니다.'],
+                    globalAction: ['<L>●</> 이전 달의 장수 동향입니다.'],
+                },
+            }));
+        });
+
+        await page.evaluate(() => {
+            const grid = document.querySelector<HTMLElement>('.history-grid')!;
+            const transition = {
+                grid,
+                mapBody: document.querySelector<HTMLElement>('.map-body')!,
+                nationBody: document.querySelector<HTMLElement>('.nation-position tbody')!,
+                removedNodes: 0,
+            };
+            new MutationObserver((records) => {
+                transition.removedNodes += records.reduce((count, record) => count + record.removedNodes.length, 0);
+            }).observe(grid, { childList: true, subtree: true });
+            (window as unknown as { __yearbookTransition: typeof transition }).__yearbookTransition = transition;
+        });
+
+        await page.getByRole('button', { name: '◀ 이전달' }).click();
+        await historyRequested;
+
+        await expect(page.locator('.history-grid')).toHaveAttribute('aria-busy', 'true');
+        await expect(page.locator('.map-body')).toHaveCount(1);
+        await expect(page.locator('.map-viewer .skeleton-lines')).toHaveCount(0);
+        await expect(page.getByText('한이 낙양을 지키고 있습니다.')).toBeVisible();
+        expect(
+            await page.evaluate(() => {
+                const transition = (
+                    window as unknown as {
+                        __yearbookTransition: {
+                            grid: Element;
+                            mapBody: Element;
+                            nationBody: Element;
+                            removedNodes: number;
+                        };
+                    }
+                ).__yearbookTransition;
+                return {
+                    gridIsSame: document.querySelector('.history-grid') === transition.grid,
+                    mapIsSame: document.querySelector('.map-body') === transition.mapBody,
+                    nationIsSame: document.querySelector('.nation-position tbody') === transition.nationBody,
+                    removedNodes: transition.removedNodes,
+                };
+            })
+        ).toEqual({ gridIsSame: true, mapIsSame: true, nationIsSame: true, removedNodes: 0 });
+
+        releaseHistory?.();
+        await expect(page.getByText('이전 달의 중원 정세입니다.')).toBeVisible();
+        await expect(page.locator('.history-grid')).toHaveAttribute('aria-busy', 'false');
+        expect(
+            await page.evaluate(() => {
+                const transition = (
+                    window as unknown as {
+                        __yearbookTransition: { grid: Element; mapBody: Element; nationBody: Element };
+                    }
+                ).__yearbookTransition;
+                return {
+                    gridIsSame: document.querySelector('.history-grid') === transition.grid,
+                    mapIsSame: document.querySelector('.map-body') === transition.mapBody,
+                    nationIsSame: document.querySelector('.nation-position tbody') === transition.nationBody,
+                };
+            })
+        ).toEqual({ gridIsSame: true, mapIsSame: true, nationIsSame: true });
+    });
 });
 
 test.describe('survey legacy parity', () => {