fix(classroom): 課題詳細の Google Classroom 配信ボタンを復活 (#1045)

docs/classroom/ui-ux.md

@@ -174,6 +174,9 @@ Google または Microsoft アカウントでサインインする画面。先
 | フェーズルート | — | `classroom-phase-teacher-detail` | — |
 | 戻るリンク | 「< 戻る」 | `classroom-back` | → teacher-dashboard |
 | クラス名 | 「第3回 チャットアプリを作ろう」 | `classroom-detail-name` | — |
+| 課題名入力 | 課題名（編集可） | `classroom-detail-assignment-name` | blur で保存 |
+| 課題配信ボタン | 「課題を配信」 | `classroom-post-assignment` | → teacher-post-assignment。**未配信のとき**表示 |
+| 課題確認リンク | 「課題を確認」 | `classroom-view-assignment` | 配信済みのとき表示（新しいタブ） |
 | 参加コード表示 | 「参加コード: 3cexm5」 | `classroom-detail-join-code` | 大きなフォントで中央表示 |
 | コード拡大ボタン | ⛶ アイコン（ツールチップ: 「全画面表示」） | `classroom-detail-expand-code` | 全画面コード表示 |
 | 有効期限 | 「有効期限: 2026/4/6」 | — | — |
@@ -184,6 +187,8 @@ Google または Microsoft アカウントでサインインする画面。先
 | 全作品ダウンロード | 「全作品ダウンロード」 | `classroom-download-all` | 左寄せ |
 | クラス削除ボタン | 「クラスを削除」 | `classroom-delete-classroom` | 赤枠ボタン、右寄せ |
 
+**課題配信ボタンの表示条件:** Google Classroom 連携はクラス（group）単位に移行したため、配信ボタン（`classroom-post-assignment`）は **クラスが GC 連携済み（`group.googleClassroomCourseId`）** であれば、その課題自体に courseId が無くても表示されます（課題の投稿先はクラスのコース）。課題単位の `googleClassroomCourseId`（v2 以前のフォールバック）が有る場合も表示されます。どちらの courseId も無い（非連携クラス）ときは表示されません。配信済み（課題に `googleClassroomAlternateLink` が保存済み）になると「Google Classroom で確認」リンク（`classroom-view-assignment`）に切り替わります。
+
 **座席グリッド:**
 
 座席番号が格子状に並び（1行 10列）、各セルの背景色で状態を表します。

infra/smalruby-classroom/lambda/handler.ts

@@ -1901,6 +1901,25 @@ async function handleImportGoogleClassroom(
   };
 }
 
+/**
+ * Resolve the Google Classroom course an assignment should be posted to.
+ *
+ * v2 moved the GC link from the assignment (classroom) to the class (group),
+ * so an assignment usually has no courseId of its own. The assignment's own
+ * field is kept only as a pre-v2 fallback and, when present, wins. Returns an
+ * empty string when neither is linked.
+ */
+export function resolveGoogleCourseId(
+  classroomItem: Record<string, unknown> | undefined,
+  groupItem: Record<string, unknown> | undefined,
+): string {
+  const own = classroomItem?.googleClassroomCourseId;
+  if (typeof own === 'string' && own) return own;
+  const group = groupItem?.googleClassroomCourseId;
+  if (typeof group === 'string' && group) return group;
+  return '';
+}
+
 async function handlePostAssignment(
   identity: TeacherIdentity,
   accessToken: string,
@@ -1916,14 +1935,15 @@ async function handlePostAssignment(
     throw new NotFoundError('Classroom not found');
   }
   // v2: the GC link lives on the class (group); the assignment's own field
-  // remains as a pre-v2 fallback.
-  let courseId = result.Item.googleClassroomCourseId as string;
+  // remains as a pre-v2 fallback. Only look the group up when the assignment
+  // itself carries no courseId.
+  let courseId = resolveGoogleCourseId(result.Item, undefined);
   if (!courseId && typeof result.Item.groupId === 'string' && result.Item.groupId) {
     const groupResult = await docClient.send(new GetCommand({
       TableName: GROUPS_TABLE,
       Key: { groupId: result.Item.groupId },
     }));
-    courseId = (groupResult.Item?.googleClassroomCourseId as string) || '';
+    courseId = resolveGoogleCourseId(result.Item, groupResult.Item);
   }
   if (!courseId) {
     throw new ValidationError('This classroom is not linked to Google Classroom');

infra/smalruby-classroom/lambda/tests/handler-assignment.test.ts

@@ -2,6 +2,7 @@ import {
   validateAssignmentPages,
   hasAssignmentContent,
   getCorsHeaders,
+  resolveGoogleCourseId,
 } from '../handler';
 
 const CLASSROOM_ID = 'aaaaaaaa-bbbb-cccc-dddd-eeeeeeeeeeee';
@@ -127,6 +128,38 @@ describe('hasAssignmentContent', () => {
   });
 });
 
+describe('resolveGoogleCourseId (post assignment target)', () => {
+  test('falls back to the group course when the assignment has no courseId (v2)', () => {
+    // The reported bug: v2 moved the GC link to the class (group), so the
+    // assignment itself is null but posting must still target the group course.
+    expect(
+      resolveGoogleCourseId(
+        { googleClassroomCourseId: null, groupId: 'g1' },
+        { googleClassroomCourseId: 'course-123' },
+      ),
+    ).toBe('course-123');
+  });
+
+  test('prefers the assignment own courseId (pre-v2 fallback wins)', () => {
+    expect(
+      resolveGoogleCourseId(
+        { googleClassroomCourseId: 'course-own' },
+        { googleClassroomCourseId: 'course-group' },
+      ),
+    ).toBe('course-own');
+  });
+
+  test('returns empty string when neither the assignment nor the group is linked', () => {
+    expect(resolveGoogleCourseId({ googleClassroomCourseId: null }, undefined)).toBe('');
+    expect(resolveGoogleCourseId({}, {})).toBe('');
+    expect(resolveGoogleCourseId(undefined, undefined)).toBe('');
+  });
+
+  test('ignores a non-string courseId', () => {
+    expect(resolveGoogleCourseId({ googleClassroomCourseId: 42 }, undefined)).toBe('');
+  });
+});
+
 describe('getCorsHeaders (assignment routes)', () => {
   test('allows PUT for the assignment endpoint', () => {
     const headers = getCorsHeaders('https://smalruby.app');

packages/scratch-gui/.prettierignore

@@ -318,6 +318,7 @@ test/unit/components/*
 !test/unit/components/connected-step.test.jsx
 !test/unit/components/mesh-self-sensor-notice.test.jsx
 !test/unit/components/student-assignment-panel.test.jsx
+!test/unit/components/teacher-class-detail.test.jsx
 !test/unit/components/mobile-bottom-tabs.test.jsx
 !test/unit/components/mobile-drawer.test.jsx
 !test/unit/components/mobile-mode-notice.test.jsx

packages/scratch-gui/src/components/classroom-modal/teacher-class-detail.jsx

@@ -238,7 +238,13 @@ const TeacherClassDetail = ({
                                     onBlur={handleAssignmentNameBlur}
                                     onChange={handleAssignmentNameChange}
                                 />
-                                {selectedClassroom.googleClassroomCourseId &&
+                                {/* Google Classroom linkage now lives on the class
+                                    (group), so an assignment posts to the group's
+                                    course even when it has no courseId of its own.
+                                    The posted/unposted branch below still keys off
+                                    the assignment's own alternateLink. */}
+                                {(selectedClassroom.googleClassroomCourseId ||
+                                    (group && group.googleClassroomCourseId)) &&
                                     (selectedClassroom.googleClassroomAlternateLink ? (
                                         <a
                                             className={

packages/scratch-gui/test/unit/components/teacher-class-detail.test.jsx

@@ -0,0 +1,83 @@
+/* eslint-env jest */
+import '@testing-library/jest-dom';
+import { render } from '@testing-library/react';
+import React from 'react';
+import { IntlProvider } from 'react-intl';
+import TeacherClassDetail from '../../../src/components/classroom-modal/teacher-class-detail.jsx';
+
+const classroom = (over = {}) => ({
+    classroomId: 'c1',
+    className: '2年1組',
+    assignmentName: '課題1',
+    joinCode: 'ABCDEF',
+    studentCount: 3,
+    googleClassroomCourseId: null,
+    googleClassroomAlternateLink: null,
+    ...over,
+});
+
+const defaultProps = () => ({
+    selectedClassroom: classroom(),
+    members: [],
+    isLoading: false,
+    onBack: jest.fn(),
+    onSelectMember: jest.fn(),
+    onDeleteMember: jest.fn(),
+    onDeleteClassroom: jest.fn(),
+    onOpenSubmission: jest.fn(),
+    onRefresh: jest.fn(),
+    onReturnSubmission: jest.fn(),
+    onDownloadAll: jest.fn(),
+    onShowCodeDisplay: jest.fn(),
+    onCloseCodeDisplay: jest.fn(),
+    onCopyInviteLink: jest.fn(),
+    onToggleCodeFullscreen: jest.fn(),
+    onShowPostAssignment: jest.fn(),
+    onUpdateAssignmentName: jest.fn(),
+});
+
+const renderDetail = (props) =>
+    render(
+        <IntlProvider locale="en">
+            <TeacherClassDetail {...defaultProps()} {...props} />
+        </IntlProvider>,
+    );
+
+describe('TeacherClassDetail — Google Classroom post button', () => {
+    test('should show the post button when only the class (group) is linked to Google Classroom', () => {
+        // Post-refactor: the assignment itself has no courseId; the link lives on the group.
+        renderDetail({
+            selectedClassroom: classroom({ googleClassroomCourseId: null }),
+            group: { groupId: 'g1', googleClassroomCourseId: 'course-123' },
+        });
+        expect(document.querySelector('[data-testid="classroom-post-assignment"]')).toBeInTheDocument();
+    });
+
+    test('should show the post button when the assignment itself has a courseId', () => {
+        renderDetail({
+            selectedClassroom: classroom({ googleClassroomCourseId: 'course-123' }),
+            group: { groupId: 'g1', googleClassroomCourseId: null },
+        });
+        expect(document.querySelector('[data-testid="classroom-post-assignment"]')).toBeInTheDocument();
+    });
+
+    test('should hide the post button when neither the class nor the assignment is linked', () => {
+        renderDetail({
+            selectedClassroom: classroom({ googleClassroomCourseId: null }),
+            group: { groupId: 'g1', googleClassroomCourseId: null },
+        });
+        expect(document.querySelector('[data-testid="classroom-post-assignment"]')).not.toBeInTheDocument();
+    });
+
+    test('should show the view-assignment link (not the post button) once this assignment was posted', () => {
+        renderDetail({
+            selectedClassroom: classroom({
+                googleClassroomCourseId: null,
+                googleClassroomAlternateLink: 'https://classroom.google.com/c/x/a/y',
+            }),
+            group: { groupId: 'g1', googleClassroomCourseId: 'course-123' },
+        });
+        expect(document.querySelector('[data-testid="classroom-view-assignment"]')).toBeInTheDocument();
+        expect(document.querySelector('[data-testid="classroom-post-assignment"]')).not.toBeInTheDocument();
+    });
+});