Implement the following plan:

GroupActivity MDX Component Implementation Plan

Overview

Create an MDX component for in-class group formation. Students must join a group of configurable size before seeing activity content. Supports partner rotation across multiple activities within the same meeting.

Usage Example

<GroupActivity id="first-discussion" group="2026-01-27-meeting" size={2}>

...content revealed after group forms...

</GroupActivity>

• id: unique identifier for this activity
• group: links activities for partner rotation tracking
• size: target group size (default: 2)

Database Schema

New file: /packages/db/src/schema/group-activities.ts

// activityGroups - represents a group instance for an activity
- id (text, primary key)
- groupKey (text) - from MDX `group` prop
- activityId (text) - from MDX `id` prop
- semester (text)
- targetSize (integer, default 2)
- createdAt (timestamp)
- unique constraint: (groupKey, activityId, semester)

// activityGroupMembers - individual memberships
- id (text, primary key)
- groupId (text, FK → activityGroups)
- userId (text, FK → users)
- joinCode (text) - 6-char alphanumeric code
- joinedAt (timestamp, nullable) - null = waiting, set = paired
- createdAt (timestamp)
- unique constraint: (groupId, userId)
- indexes: joinCode, userId

API Endpoints

New file: /apps/api/src/routes/group-activities.ts

GET /api/group-activities/:groupKey/:activityId

• Creates group/membership if needed
• Returns: { status, joinCode, targetSize, memberCount, members, priorPartners }

POST /api/group-activities/:groupKey/:activityId/join

• Body: { partnerCode: string }
• Validates code, checks partner rotation, creates pairing
• Returns: { success: boolean, error?: string }

Admin Endpoints

GET /api/admin/group-activities/:groupKey/:activityId

• Returns all groups and members for instructor dashboard
• Response: { groups: [{ id, members: [...], memberCount, targetSize }] }

POST /api/admin/group-activities/:groupKey/:activityId/unlock

• Body: { userId: string }
• Manually marks a solo student as complete (instructor override)

Join Code Strategy

• 6 characters from unambiguous alphabet: 23456789ABCDEFGHJKMNPQRSTUVWXYZ
• Displayed as ABC-123 format for readability
• ~594 million combinations (no collision risk for classroom sizes)

Component Structure

Server Component: /apps/web/components/mdx/group-activity.tsx

• Checks auth, fetches initial status via serverApiFetch
• If complete: render children directly (no client JS needed)
• If pending: render client component

Client Component: /apps/web/components/mdx/group-activity-client.tsx

• Displays user's join code with copy button
• Input field for partner's code
• SWR polling (3s interval while pending)
• Shows error messages, prior partner warnings
• Reveals content when group completes

Partner Rotation Logic

For activities sharing the same group value:

1. Query all other activities in the same groupKey
2. Find user's completed memberships in those activities
3. Collect partner user IDs from those groups
4. Block joining if selected partner is in prior partners list

Group Completion & Overflow

Key behavior: Content unlocks at target size, but group remains joinable.

1. Group reaches target size (e.g., 2) → content unlocks immediately
2. Join code stays visible with "Show code for another student" button
3. 3rd student entering code sees: "Join as 3rd member?" confirmation
4. API allows memberCount <= targetSize + 1

Instructor override: Admin can manually unlock content for a solo student if needed (edge case fallback).

Files to Create/Modify

Verification

1. Run bun run db:push to apply schema
2. Start dev servers: bun run dev
3. Create test MDX with <GroupActivity> component
4. Open in two browser sessions (different users)
5. Verify: code display, joining, content reveal, partner rotation

If you need specific details from before exiting plan mode (like exact code snippets, error messages, or content you generated), read the full transcript at: ~/.claude/projects/-Users-challen-www-usingandunderstanding-ai/4f94a2c6-4290-4ff5-8c31-b893726a7fa2.jsonl

Also, please write e2e tests for this. You should probably write them first, make sure that they fail, and then work towards them passing.

This session is being continued from a previous conversation that ran out of context. The summary below covers the earlier portion of the conversation.

Analysis: Let me analyze the conversation chronologically to capture all important details:

1. Initial Request: User wants to implement a GroupActivity MDX component for in-class group formation based on a detailed plan. The plan includes:

   • Database schema for group activities (activityGroups and activityGroupMembers tables)
   • API endpoints for group activities and admin endpoints
   • Server and client components for the MDX component
   • E2E tests (user explicitly requested tests be written first in TDD style)

2. Implementation Progress:

   • Created database schema in /packages/db/src/schema/group-activities.ts
   • Created API routes in /apps/api/src/routes/group-activities.ts
   • Created admin routes in /apps/api/src/routes/admin/group-activities.ts
   • Registered routes in API index
   • Created server component in /apps/web/components/mdx/group-activity.tsx
   • Created client component in /apps/web/components/mdx/group-activity-client.tsx
   • Created test pages at /apps/web/app/testing/components/group-activity/ and group-activity-2/
   • Registered GroupActivity in mdx-components.tsx
   • Wrote E2E tests in /testing/e2e/tests/group-activity.spec.ts

3. Key Errors Encountered:

   • TypeScript error: eq(activityGroupMembers.joinedAt, null) - fixed by using isNull() instead
   • Tests failing with empty join code - the SWR data fetching wasn't working
   • Discovered the issue is with cross-origin cookie handling between [local-hostname] and [local-hostname]
   • Server-side API fetch returns 500 error
   • Client-side SWR fetch returns 401 error (cookies not being sent)

4. Current Issue: The tests are failing because:

   • Server-side serverApiFetch call is failing with 500 error
   • Client-side SWR fetch is failing with 401 error (authentication cookie not being sent cross-origin)
   • The screenshot shows "Failed to load group activity. Please refresh the page." with "API error: 401"

5. Most Recent Work: Added debugging to display both server and client errors in the UI to understand what's happening. The last test run still shows the same failure pattern.

6. User Messages:

   • Initial request to implement the plan with detailed specification
   • Request to write e2e tests first (TDD approach)

Summary:

1. Primary Request and Intent: Implement a GroupActivity MDX component for in-class group formation following a detailed plan. Students must join a group of configurable size before seeing activity content. The component supports partner rotation across multiple activities. User explicitly requested E2E tests be written first following TDD approach, with tests failing initially before implementation makes them pass.

2. Key Technical Concepts:

   • Drizzle ORM for database schema with PostgreSQL
   • Hono for API routes with Zod validation
   • Next.js Server Components with async data fetching
   • React Client Components with SWR for polling
   • Better Auth for session management
   • Playwright for E2E testing
   • Cross-origin cookie handling (SameSite attributes)
   • Join codes with unambiguous alphabet: 23456789ABCDEFGHJKMNPQRSTUVWXYZ

3. Files and Code Sections:

   • /packages/db/src/schema/group-activities.ts (CREATED)

     • Database schema for activity groups and members

     export const activityGroups = pgTable(
       "activity_groups",
       {
         id: text("id").primaryKey(),
         groupKey: text("group_key").notNull(),
         activityId: text("activity_id").notNull(),
         semester: text("semester").notNull(),
         targetSize: integer("target_size").notNull().default(2),
         createdAt: timestamp("created_at", { mode: "date" }).notNull().defaultNow(),
       },
       (table) => [
         unique("activity_groups_unique").on(table.groupKey, table.activityId, table.semester),
         index("activity_groups_group_key_idx").on(table.groupKey),
       ]
     );
     
     export const activityGroupMembers = pgTable(
       "activity_group_members",
       {
         id: text("id").primaryKey(),
         groupId: text("group_id").notNull().references(() => activityGroups.id, { onDelete: "cascade" }),
         userId: text("user_id").notNull().references(() => users.id, { onDelete: "cascade" }),
         joinCode: text("join_code").notNull(),
         joinedAt: timestamp("joined_at", { mode: "date" }),
         createdAt: timestamp("created_at", { mode: "date" }).notNull().defaultNow(),
       },
       (table) => [
         unique("activity_group_members_unique").on(table.groupId, table.userId),
         index("activity_group_members_join_code_idx").on(table.joinCode),
         index("activity_group_members_user_id_idx").on(table.userId),
       ]
     );
     

   • /apps/api/src/routes/group-activities.ts (CREATED)

     • API routes for getting group status and joining groups
     • Key endpoints: GET /:groupKey/:activityId and POST /:groupKey/:activityId/join
     • Uses findOrCreateMembership and getPriorPartners helper functions

   • /apps/api/src/routes/admin/group-activities.ts (CREATED)

     • Admin endpoints for listing groups and unlocking solo students

   • /apps/web/components/mdx/group-activity.tsx (CREATED)

     • Server component that checks auth and fetches initial status
     • Currently includes debugging for server error:

     let initialStatus: GroupStatusResponse | null = null;
     let serverError: string | null = null;
     try {
       initialStatus = await serverApiFetch<GroupStatusResponse>(
         `/api/group-activities/${encodeURIComponent(group)}/${encodeURIComponent(id)}?semester=${encodeURIComponent(semester)}&targetSize=${size}`
       );
     } catch (err) {
       serverError = err instanceof Error ? err.message : "Unknown server error";
       console.error("[GroupActivity] Server fetch error:", serverError);
     }
     

   • /apps/web/components/mdx/group-activity-client.tsx (CREATED)

     • Client component with SWR polling, join code display, and partner code input
     • Includes error display for both server and client errors
     • Shows loading state, error state, pending state, and complete state

   • /testing/e2e/tests/group-activity.spec.ts (CREATED)

     • E2E tests covering: unauthenticated access, authenticated user sees join code, two users forming a group, invalid code handling, own code rejection, partner rotation, group overflow, and content unlock persistence

   • /testing/e2e/utils/authHelper.ts (MODIFIED)

     • Cookie name is __Secure-better-auth.session_token
     • SameSite is Lax (tried None but broke auth)

   • /apps/api/src/routes/e2e.ts (MODIFIED)

     • Added cleanup for activityGroupMembers table

4. Errors and fixes:

   • TypeScript error with eq(joinedAt, null):
     • Fixed by using isNull(activityGroupMembers.joinedAt) instead
   • Tests failing with empty join code:
     • Added toHaveText(/^[A-Z0-9]{3}-[A-Z0-9]{3}$/, { timeout: 10000 }) to wait for code to load
   • Authentication issues with cookie name:
     • Tried changing from __Secure-better-auth.session_token to better-auth.session_token - broke all auth
     • Reverted back to __Secure-better-auth.session_token
   • SameSite cookie issues:
     • Tried changing from Lax to None - didn't fix the issue
     • Reverted to Lax
   • ONGOING: Server returns 500, client returns 401:
     • Server-side serverApiFetch fails with 500 Internal Server Error
     • Client-side SWR fetch fails with 401 (cookies not sent cross-origin)
     • Added detailed error messages to diagnose

5. Problem Solving:

   • Database schema was successfully created and pushed with bun run db:push
   • Tables exist: activity_groups and activity_group_members with correct structure
   • TypeScript compiles without errors
   • Impersonation and apply tests pass (authentication works for those)
   • The apply page uses the same SWR fetcher pattern and works because server-side fetch succeeds with fallback data
   • ONGOING: Need to diagnose why server-side fetch returns 500 for group-activities while it works for applications

6. All user messages:

   • "Implement the following plan: [detailed GroupActivity MDX Component Implementation Plan]"
   • "Also, please write e2e tests for this. You should probably write them first, make sure that they fail, and then work towards them passing."

7. Pending Tasks:

   • Fix the 500 error from server-side API fetch
   • Fix the 401 error from client-side SWR fetch (cross-origin cookie issue)
   • Get all E2E tests passing

8. Current Work: Debugging why the API returns 500 error when server component calls serverApiFetch for group-activities endpoint. Added debugging to display both server and client errors in the UI. The last screenshot showed "Failed to load group activity" with "API error: 401" for the client-side error. Need to see the actual server error message.

   The most recent test run screenshot needs to be viewed to see the detailed error messages that were added.

9. Optional Next Step: View the latest screenshot to see the detailed server and client error messages, then diagnose why the server-side fetch returns 500. The issue is likely in the findOrCreateMembership function or database operations in the API route. May need to check API server logs or add more specific error handling.

   Quote from work: "Let me add debugging to understand what's happening during the server-side fetch." - Added serverError tracking and display to see what error the server-side fetch encounters.

If you need specific details from before compaction (like exact code snippets, error messages, or content you generated), read the full transcript at: ~/.claude/projects/-Users-challen-www-usingandunderstanding-ai/fb4c8028-d94b-43ef-9138-6977e22eccee.jsonl Please continue the conversation from where we left it off without asking the user any further questions. Continue with the last task that you were asked to work on.

Your task

First, run git status, git diff, and git log --oneline -10 to understand the current state.

Then add and commit all modified files with a descriptive message. Break the changes into multiple commits if appropriate. If there are untracked files, ask if they should be added or added to the appropriate .gitignore file. The user may also want to take over at this point, so provide an abort option as well. Always check changes for unnecessary debugging statements or logging that might have been accidentally included. Prompt the user if you find any, and offer to remove each one by one. Do not use interactive git staging (git add -p) as it does not work.

Read the output file to retrieve the result: [tmp-path]

OK. Going back to the features. No need for copy to clipboard, since student will be reading these off each others monitors. Also we should probably make allowances for the total number of students present when enforcing mixing. For example, if there are only 4 students and four pair-wise activities, then there's no way for students to use a different partner for each group. We'll need to calculate this carefully. Can we do it properly? Maybe allowing for a certain amount of reuse? Ah, and measuring the total number of students is tricky. Probably the first <GroupActivity in the series should do this as an estimate? But students may come and go during the activity. This is hard! What do you suggest? I don't want to prevent students from starting unnecessarily while also creating a bit of friction if they keep trying to work with the same person.