refactor: remove unused classroom fields

apps/server/src/database/database-migrations.spec.ts

@@ -10,6 +10,13 @@ interface MockTable {
   name: string;
   columns: MockColumn[];
 }
+interface MockRunner {
+  release: jest.Mock;
+  connect: jest.Mock;
+  query: jest.Mock;
+  getTables: jest.Mock;
+  getTable: jest.Mock;
+}
 
 function mockRunner(overrides: {
   getTables?: MockTable[];
@@ -28,10 +35,10 @@ function mockRunner(overrides: {
     query.mockRejectedValue(overrides.queryError);
   }
 
-  return { release, connect, query, getTables, getTable };
+  return { release, connect, query, getTables, getTable } satisfies MockRunner;
 }
 
-function createDataSource(runner: ReturnType<typeof mockRunner>, dbType: string = 'better-sqlite3') {
+function createDataSource(runner: MockRunner, dbType: string = 'better-sqlite3') {
   return {
     options: { type: dbType },
     createQueryRunner: jest.fn().mockReturnValue(runner),
@@ -46,12 +53,13 @@ interface MigrationsPrivate {
   normalizeClassDates(): Promise<void>;
   ensureCourseAttendanceSchema(): Promise<void>;
   protectAttendanceHistory(): Promise<void>;
+  removeUnusedClassroomColumns(): Promise<void>;
 }
 
 describe('DatabaseMigrationsService — ensureAiConfigTable', () => {
   let service: MigrationsPrivate & DatabaseMigrationsService;
 
-  async function bootstrap(runner: ReturnType<typeof mockRunner>) {
+  async function bootstrap(runner: MockRunner) {
     const dataSource = createDataSource(runner);
     const module: TestingModule = await Test.createTestingModule({
       providers: [
@@ -220,7 +228,7 @@ describe('DatabaseMigrationsService — course attendance schema', () => {
 describe('DatabaseMigrationsService — protectAttendanceHistory', () => {
   let service: MigrationsPrivate & DatabaseMigrationsService;
 
-  async function bootstrap(runner: ReturnType<typeof mockRunner>, dbType: string = 'better-sqlite3') {
+  async function bootstrap(runner: MockRunner, dbType: string = 'better-sqlite3') {
     const dataSource = createDataSource(runner, dbType);
     const module: TestingModule = await Test.createTestingModule({
       providers: [
@@ -416,7 +424,49 @@ describe('DatabaseMigrationsService — protectAttendanceHistory', () => {
   });
 });
 
-async function bootstrapCourseAttendance(runner: ReturnType<typeof mockRunner>) {
+describe('DatabaseMigrationsService — classroom cleanup', () => {
+  let cleanupService: MigrationsPrivate & DatabaseMigrationsService;
+
+  async function bootstrapClassroomCleanup(runner: MockRunner) {
+    const dataSource = createDataSource(runner);
+    const module: TestingModule = await Test.createTestingModule({
+      providers: [
+        DatabaseMigrationsService,
+        { provide: getDataSourceToken(), useValue: dataSource },
+      ],
+    }).compile();
+    cleanupService = module.get(DatabaseMigrationsService);
+  }
+
+  it('drops legacy classroom fields when present', async () => {
+    const runner = mockRunner({
+      getTables: [{ name: 'classrooms', columns: [] }],
+      getTable: {
+        name: 'classrooms',
+        columns: [{ name: 'id' }, { name: 'course_type' }, { name: 'supervisor' }],
+      },
+    });
+    await bootstrapClassroomCleanup(runner);
+
+    await cleanupService.removeUnusedClassroomColumns();
+
+    expect(runner.query).toHaveBeenCalledWith('ALTER TABLE classrooms DROP COLUMN course_type');
+    expect(runner.query).toHaveBeenCalledWith('ALTER TABLE classrooms DROP COLUMN supervisor');
+    expect(runner.release).toHaveBeenCalled();
+  });
+
+  it('does nothing when the classrooms table is absent', async () => {
+    const runner = mockRunner({ getTables: [] });
+    await bootstrapClassroomCleanup(runner);
+
+    await cleanupService.removeUnusedClassroomColumns();
+
+    expect(runner.query).not.toHaveBeenCalled();
+    expect(runner.release).toHaveBeenCalled();
+  });
+});
+
+async function bootstrapCourseAttendance(runner: MockRunner) {
   const dataSource = createDataSource(runner);
   const module: TestingModule = await Test.createTestingModule({
     providers: [