Gamification: Streaks — record activity + current/longest in sidebar

[ljm20088]

Parent PRD

#41

What to build

Streaks, end-to-end. When a student completes at least one lesson in a UTC day, a streak activity is recorded; the sidebar shows the current streak and longest-ever streak with a flame icon (visible even at 0 days).

• New streak_activities table (one row per user per UTC day). See PRD "Database Changes".
• Add denormalized currentStreak and longestStreak integer columns to the users table (decided: store on users), updated on each lesson completion. See PRD "Further Notes".
• Extend progressService.markLessonComplete to record streak activity (idempotent per UTC day — multiple completions in one day = one streak day) and recompute current/longest. Streak resets to 0 when a full UTC day passes with no completion. UTC-only, no grace/freeze. See PRD "Streak System", user stories 12-14.
• Sidebar shows current streak + longest streak with a flame/streak icon; the section is always visible, even at 0 days (user story 9).

Acceptance criteria

• streak_activities table + currentStreak/longestStreak columns added with migration (pnpm db:generate / pnpm db:migrate)
• Completing a lesson records at most one streak activity per UTC day
• Consecutive UTC days increase the current streak; a missed UTC day resets it to 0
• Longest streak is tracked and never decreases
• Sidebar shows current + longest streak with a flame icon, visible even at 0
• Tests cover consecutive days, same-day dedup, and gap reset
• pnpm test and typecheck pass

Blocked by

• Blocked by Gamification: XP foundation — earn XP on lesson completion + level in sidebar #77

User stories addressed

• User story 7
• User story 8
• User story 9
• User story 12
• User story 13
• User story 14

[DataRalf]

Completed in commit ed88455 on main

What changed

• Database: streak_activities table added with migration 0009 — one row per user per UTC day
• Streak service (app/services/streakService.ts): recordStreakActivity(userId) records one entry per UTC day (idempotent); getStreakData(userId) computes current and longest streak from the activity log
• Route wiring: lesson mark-complete action in courses.$slug.lessons.$lessonId.tsx calls recordStreakActivity(currentUserId) alongside awardXp() — multiple completions in one UTC day count as a single streak day
• Layout loader: provides currentStreak and longestStreak in the gamification data for students
• Sidebar: streak section with flame icon showing current streak and best streak, visible even at 0 days

Tests

11 new tests in app/services/streakService.test.ts:

• recordStreakActivity: first-call record, same-day dedup, different-user recording
• getStreakData: no activity (0/0), today only (1/1), consecutive days, reset on gap, longest preservation across multiple runs, yesterday-inclusive current streak, stale activity (>1 day ago), user scoping

All 403 tests passing, typecheck clean.

Acceptance criteria — all met

• streak_activities table added with a Drizzle migration (one row per user per UTC day)
• Completing a lesson records at most one streak activity per UTC day
• Consecutive UTC days increase the current streak; a missed UTC day resets it to 0
• Longest streak is tracked and never decreases
• Sidebar shows current + longest streak with a flame icon, visible even at 0
• Tests cover consecutive days, same-day dedup, and gap reset
• pnpm test and typecheck pass