feat: remove cover page

server/db.test.ts

@@ -1,3 +1,6 @@
+import { existsSync, rmSync } from 'node:fs'
+import { tmpdir } from 'node:os'
+import { join } from 'node:path'
 import { afterEach, describe, expect, it, setSystemTime } from 'bun:test'
 import { createEmptyBook, createEmptyTeachingDesign } from '../src/domain/teachingDesign'
 import {
@@ -10,6 +13,12 @@ afterEach(() => {
   setSystemTime()
 })
 
+function tempDbPath(name: string): string {
+  const path = join(tmpdir(), `fake-teaching-design-${name}-${crypto.randomUUID()}.db`)
+  if (existsSync(path)) rmSync(path)
+  return path
+}
+
 describe('db', () => {
   it('creates a book with empty data', () => {
     const db = openDb(':memory:')
@@ -55,13 +64,85 @@ describe('db', () => {
     const db = openDb(':memory:')
     const created = createBook(db, '示例整本')
     const data = createEmptyBook()
-    data.cover.courseName = 'Web 前端开发'
+    data.designs.push(createEmptyTeachingDesign('1.md'))
 
     setSystemTime(new Date('2026-02-01T00:00:00.000Z'))
     const result = saveBookData(db, created.id, data)
 
     expect(result).toEqual({ id: created.id, name: '示例整本', updatedAt: '2026-02-01T00:00:00.000Z' })
-    expect(getBook(db, created.id)?.data.cover.courseName).toBe('Web 前端开发')
+    expect(getBook(db, created.id)?.data).not.toHaveProperty('cover')
+  })
+
+  it('migrates legacy cover data and cover selection on open', () => {
+    const path = tempDbPath('cover-migration')
+    const db = openDb(path)
+    const design = createEmptyTeachingDesign('1.md')
+    const legacy = {
+      schemaVersion: 1,
+      cover: { courseName: '旧课程', teacherName: '旧教师' },
+      designs: [design],
+      selectedId: 'cover',
+      updatedAt: '2026-01-01T00:00:00.000Z',
+    }
+    db.run('INSERT INTO books (id, name, data, created_at, updated_at) VALUES (?, ?, ?, ?, ?)', [
+      'legacy-1',
+      '旧整本',
+      JSON.stringify(legacy),
+      '2026-01-01T00:00:00.000Z',
+      '2026-01-01T00:00:00.000Z',
+    ])
+    db.close()
+
+    const reopened = openDb(path)
+    const migrated = getBook(reopened, 'legacy-1')!.data
+    const raw = reopened.query<{ data: string }, [string]>('SELECT data FROM books WHERE id = ?').get('legacy-1')!.data
+    reopened.close()
+    rmSync(path)
+
+    expect(migrated).not.toHaveProperty('cover')
+    expect(migrated.selectedId).toBe(design.id)
+    expect(JSON.parse(raw)).not.toHaveProperty('cover')
+  })
+
+  it('migrates legacy cover selection to null when no lessons exist', () => {
+    const path = tempDbPath('empty-cover-migration')
+    const db = openDb(path)
+    db.run('INSERT INTO books (id, name, data, created_at, updated_at) VALUES (?, ?, ?, ?, ?)', [
+      'legacy-empty',
+      '空整本',
+      JSON.stringify({
+        schemaVersion: 1,
+        cover: { courseName: '旧课程', teacherName: '旧教师' },
+        designs: [],
+        selectedId: 'cover',
+        updatedAt: '2026-01-01T00:00:00.000Z',
+      }),
+      '2026-01-01T00:00:00.000Z',
+      '2026-01-01T00:00:00.000Z',
+    ])
+    db.close()
+
+    const reopened = openDb(path)
+    const migrated = getBook(reopened, 'legacy-empty')!.data
+    reopened.close()
+    rmSync(path)
+
+    expect(migrated).not.toHaveProperty('cover')
+    expect(migrated.selectedId).toBeNull()
+  })
+
+  it('normalizes invalid selected ids to the first lesson', () => {
+    const db = openDb(':memory:')
+    const created = createBook(db, '示例整本')
+    const data = createEmptyBook()
+    const design = createEmptyTeachingDesign('1.md')
+    data.designs.push(design)
+    db.run('UPDATE books SET data = ? WHERE id = ?', [
+      JSON.stringify({ ...data, selectedId: 'missing-id' }),
+      created.id,
+    ])
+
+    expect(getBook(db, created.id)?.data.selectedId).toBe(design.id)
   })
 
   it('returns null when saving data for a missing book', () => {

server/db.ts

@@ -28,6 +28,16 @@ interface BookRow {
   updated_at: string
 }
 
+type StoredTeachingBook = Omit<TeachingBook, 'selectedId'> & {
+  cover?: unknown
+  selectedId?: string | null
+}
+
+interface NormalizedBookData {
+  data: TeachingBook
+  changed: boolean
+}
+
 export interface UserRecord {
   id: string
   username: string
@@ -77,10 +87,59 @@ const SCHEMA = `
   )
 `
 
+function normalizeBookData(raw: StoredTeachingBook): NormalizedBookData {
+  const data = { ...raw, designs: Array.isArray(raw.designs) ? raw.designs : [] }
+  let changed = false
+
+  if ('cover' in data) {
+    delete data.cover
+    changed = true
+  }
+
+  const selectedId = data.selectedId ?? null
+  const firstDesignId = data.designs[0]?.id ?? null
+  const selectedExists =
+    selectedId !== null && data.designs.some((design) => design.id === selectedId)
+
+  let normalizedSelectedId: TeachingBook['selectedId']
+  if (selectedId === 'cover' || (selectedId !== null && !selectedExists)) {
+    normalizedSelectedId = firstDesignId
+    changed = selectedId !== normalizedSelectedId || changed
+  } else {
+    normalizedSelectedId = selectedId as TeachingBook['selectedId']
+  }
+
+  return {
+    data: {
+      schemaVersion: data.schemaVersion,
+      designs: data.designs,
+      selectedId: normalizedSelectedId,
+      updatedAt: data.updatedAt,
+    },
+    changed,
+  }
+}
+
+function parseBookData(data: string): TeachingBook {
+  return normalizeBookData(JSON.parse(data) as StoredTeachingBook).data
+}
+
+function migrateStoredBooks(db: Database): void {
+  const rows = db.query<{ id: string; data: string }, []>('SELECT id, data FROM books').all()
+
+  for (const row of rows) {
+    const normalized = normalizeBookData(JSON.parse(row.data) as StoredTeachingBook)
+    if (normalized.changed) {
+      db.run('UPDATE books SET data = ? WHERE id = ?', [JSON.stringify(normalized.data), row.id])
+    }
+  }
+}
+
 export function openDb(path: string): Database {
   const db = new Database(path)
   db.run('PRAGMA foreign_keys = ON')
   db.run(SCHEMA)
+  migrateStoredBooks(db)
   return db
 }
 
@@ -93,7 +152,7 @@ export function listBooks(db: Database): BookSummary[] {
     id: row.id,
     name: row.name,
     updatedAt: row.updated_at,
-    lessonCount: (JSON.parse(row.data) as TeachingBook).designs.length,
+    lessonCount: parseBookData(row.data).designs.length,
   }))
 }
 
@@ -124,7 +183,7 @@ export function getBook(db: Database, id: string): BookRecord | null {
     id: row.id,
     name: row.name,
     updatedAt: row.updated_at,
-    data: JSON.parse(row.data) as TeachingBook,
+    data: parseBookData(row.data),
   }
 }
 
@@ -135,7 +194,8 @@ export function saveBookData(db: Database, id: string, data: TeachingBook): Book
   if (!existing) return null
 
   const now = new Date().toISOString()
-  db.run('UPDATE books SET data = ?, updated_at = ? WHERE id = ?', [JSON.stringify(data), now, id])
+  const normalized = normalizeBookData(data as unknown as StoredTeachingBook).data
+  db.run('UPDATE books SET data = ?, updated_at = ? WHERE id = ?', [JSON.stringify(normalized), now, id])
 
   return { id, name: existing.name, updatedAt: now }
 }

server/routes/books.test.ts

@@ -1,7 +1,7 @@
 import { beforeEach, describe, expect, it } from 'bun:test'
 import type { Database } from 'bun:sqlite'
 import { Hono } from 'hono'
-import { createEmptyBook } from '../../src/domain/teachingDesign'
+import { createEmptyBook, createEmptyTeachingDesign } from '../../src/domain/teachingDesign'
 import { openDb } from '../db'
 import { createBooksRouter } from './books'
 
@@ -64,22 +64,22 @@ describe('books routes', () => {
     expect(res.status).toBe(404)
   })
 
-  it('saves book data', async () => {
+  it('saves book data without cover state', async () => {
     const created = await createViaApi('示例整本')
 
     const data = createEmptyBook()
-    data.cover.courseName = 'Web 前端开发'
+    data.designs.push(createEmptyTeachingDesign('1.md'))
 
     const res = await app.request(`/api/books/${created.id}`, {
       method: 'PUT',
       headers: { 'Content-Type': 'application/json' },
-      body: JSON.stringify({ data }),
+      body: JSON.stringify({ data: { ...data, cover: { courseName: '旧课程', teacherName: '旧教师' } } }),
     })
     expect(res.status).toBe(200)
 
     const fetched = await app.request(`/api/books/${created.id}`)
-    const body = (await fetched.json()) as { data: { cover: { courseName: string } } }
-    expect(body.data.cover.courseName).toBe('Web 前端开发')
+    const body = (await fetched.json()) as { data: Record<string, unknown> }
+    expect(body.data).not.toHaveProperty('cover')
   })
 
   it('returns 404 when saving data for a missing book', async () => {