formatting

apps/api/src/app.ts

@@ -27,7 +27,7 @@ export function createApp() {
 
   const store = new InMemoryGameSessionStore();
   app.use("/api/v1", createApiRouter(store));
-  
+
   app.use(errorHandler);
 
   return app;

apps/api/src/controllers/gameController.test.ts

@@ -197,7 +197,7 @@ describe("POST /api/v1/game/answer", () => {
     expect(body.success).toBe(false);
     expect(body.error).toContain("Question already answered");
   });
-  
+
   it("returns 400 when a field has an invalid value", async () => {
     const res = await request(app)
       .post("/api/v1/game/start")

apps/api/src/errors/AppError.ts

@@ -30,4 +30,4 @@ export class UnprocessableEntityError extends AppError {
   constructor(message: string) {
     super(message, 422);
   }
-}
+}

apps/api/src/routes/gameRouter.ts

@@ -14,6 +14,6 @@ export const createGameRouter = (store: GameSessionStore): Router => {
 
   router.post("/start", controller.createGame as express.RequestHandler);
   router.post("/answer", controller.submitAnswer as express.RequestHandler);
-  
+
   return router;
 };

documentation/roasts/gameService.md

@@ -1,11 +1,11 @@
 # 🔥 GameService Roast: `apps/api/src/services/gameService.ts`
 
-> *"It works on my machine" is not a scalability strategy.*
+> _"It works on my machine" is not a scalability strategy._
 
 **Project:** lila — Vocabulary Trainer  
 **File Roasted:** `gameService.ts`  
 **Date:** $(date)  
-**Roaster:** Qwen3.6  
+**Roaster:** Qwen3.6
 
 ---
 
@@ -28,8 +28,8 @@
 **Location:** `gameService.ts:45-58` + `InMemoryGameSessionStore.ts:update()`
 
 // Current flow (VULNERABLE):
-const session = await store.get(submission.sessionId);  // READ
+const session = await store.get(submission.sessionId); // READ
-const updatedAnswers = new Map(session.answers);         // MODIFY (local copy)
+const updatedAnswers = new Map(session.answers); // MODIFY (local copy)
 updatedAnswers.delete(submission.questionId);
 await store.update(submission.sessionId, { answers: updatedAnswers }); // WRITE
 
@@ -46,64 +46,55 @@ Fix Options:
 
 // Option A: Add atomic operation to store interface
 interface GameSessionStore {
-  deleteAnswer(sessionId: string, questionId: string): Promise<boolean>;
+deleteAnswer(sessionId: string, questionId: string): Promise<boolean>;
 }
 
 // Option B: Use Valkey Lua script for atomic read-modify-write
 // Option C: Optimistic locking with version numbers
 
-Priority: 🔴 CRITICAL — Data integrity issue
+Priority: 🔴 CRITICAL — Data integrity issue 2. N+1 Query: Database Performance Bomb
-2. N+1 Query: Database Performance Bomb
 Location: gameService.ts:24-26 + termModel.ts:getDistractors()
 
 // For each of N terms, we call getDistractors():
 const questions: GameQuestion[] = await Promise.all(
-  terms.map(async (term) => {
+terms.map(async (term) => {
-    const distractorTexts = await getDistractors(term.termId, ...); // 🚩 N queries!
+const distractorTexts = await getDistractors(term.termId, ...); // 🚩 N queries!
-  })
+})
 );
 
 Impact Analysis:
 Rounds
-	
 DB Queries
-	
 At 50 concurrent users
 3
-	
 1 + 3 = 4
-	
 200 queries/min
 10
-	
 1 + 10 = 11
-	
 550 queries/min
 20
-	
 1 + 20 = 21
-	
 1,050 queries/min
 Each getDistractors() runs:
 
-SELECT text FROM terms 
+SELECT text FROM terms
-JOIN translations ON ... 
+JOIN translations ON ...
-WHERE pos = $1 AND difficulty = $2 AND term_id != $3 AND text != $4 
+WHERE pos = $1 AND difficulty = $2 AND term_id != $3 AND text != $4
 ORDER BY RANDOM() LIMIT 6
 
 Fix: Batch Fetch Distractors
 
 // Fetch all distractors in ONE query
 const allDistractors = await db
-  .select({ termId: terms.id, text: translations.text })
+.select({ termId: terms.id, text: translations.text })
-  .from(terms)
+.from(terms)
-  .innerJoin(translations, /* ... */)
+.innerJoin(translations, /_ ... _/)
-  .where(and(
+.where(and(
-    eq(terms.pos, pos),
+eq(terms.pos, pos),
-    eq(translations.difficulty, difficulty),
+eq(translations.difficulty, difficulty),
-    inArray(terms.id, termIds), // Batch!
+inArray(terms.id, termIds), // Batch!
-  ))
+))
-  .limit(DISTRACTOR_FETCH_COUNT * termIds.length);
+.limit(DISTRACTOR_FETCH_COUNT \* termIds.length);
 
 // Group by termId in JS, then slice to 3 unique distractors per term
 const distractorsByTerm = groupByTermId(allDistractors);
@@ -111,10 +102,10 @@ const distractorsByTerm = groupByTermId(allDistractors);
 Priority: 🔴 CRITICAL — Performance/scalability issue
 
 3. Error Handling Inconsistency
-Location: gameService.ts:33-36
+   Location: gameService.ts:33-36
 
 if (uniqueDistractors.length < 3) {
-  throw new Error(`Not enough unique distractors for term: ${term.targetText}`); // 🚩
+throw new Error(`Not enough unique distractors for term: ${term.targetText}`); // 🚩
 }
 
 Problem: Raw Error bypasses your errorHandler middleware:
@@ -127,15 +118,14 @@ Fix:
 import { UnprocessableEntityError } from "../errors/AppError.js";
 
 if (uniqueDistractors.length < 3) {
-  logger.warn({ termId: term.termId, uniqueCount: uniqueDistractors.length }, 
+logger.warn({ termId: term.termId, uniqueCount: uniqueDistractors.length },
-              "insufficient_distractors");
+"insufficient_distractors");
-  throw new UnprocessableEntityError(
+throw new UnprocessableEntityError(
-    `Not enough unique distractors for term: ${term.targetText}`
+`Not enough unique distractors for term: ${term.targetText}`
-  );
+);
 }
 Priority: 🟡 HIGH — Observability & UX issue
-⚠️ High-Severity Smells
+⚠️ High-Severity Smells 4. Code Duplication: Singleplayer vs Multiplayer
-4. Code Duplication: Singleplayer vs Multiplayer
 Compare: gameService.ts vs multiplayerGameService.ts
 // gameService.ts
 const optionTexts = [term.targetText, ...uniqueDistractors.slice(0, 3)];
@@ -157,30 +147,29 @@ Fix: Extract pure function to @lila/shared or new @lila/game-logic:
 
 // packages/shared/src/game-logic.ts
 export const buildQuestionOptions = (
-  correctAnswer: string,
+correctAnswer: string,
-  distractors: string[],
+distractors: string[],
-  optionCount: number = 4
+optionCount: number = 4
 ): { options: AnswerOption[]; correctOptionId: number } => {
-  const uniqueDistractors = [...new Set(distractors.filter(d => d !== correctAnswer))];
+const uniqueDistractors = [...new Set(distractors.filter(d => d !== correctAnswer))];
-  const optionTexts = [correctAnswer, ...uniqueDistractors.slice(0, optionCount - 1)];
+const optionTexts = [correctAnswer, ...uniqueDistractors.slice(0, optionCount - 1)];
-  const shuffled = shuffleSecure(optionTexts);
+const shuffled = shuffleSecure(optionTexts);
-  const correctOptionId = shuffled.indexOf(correctAnswer);
+const correctOptionId = shuffled.indexOf(correctAnswer);
-  
+
-  return {
+return {
-    options: shuffled.map((text, idx) => ({ optionId: idx, text })),
+options: shuffled.map((text, idx) => ({ optionId: idx, text })),
-    correctOptionId
+correctOptionId
-  };
+};
 };
 
-Priority: 🟡 HIGH — Maintainability issue
+Priority: 🟡 HIGH — Maintainability issue 5. Shuffle Bias: Math.random() Trap
-5. Shuffle Bias: Math.random() Trap
 Location: utils.ts:shuffleArray() + multiplayerGameService.ts:shuffle()
 
 export const shuffleArray = <T>(array: T[]): T[] => {
-  for (let i = result.length - 1; i > 0; i--) {
+for (let i = result.length - 1; i > 0; i--) {
-    const j = Math.floor(Math.random() * (i + 1)); // 🚩 Modulo bias + non-crypto RNG
+const j = Math.floor(Math.random() \* (i + 1)); // 🚩 Modulo bias + non-crypto RNG
-    // ...
+// ...
-  }
+}
 };
 
 The Math:
@@ -199,65 +188,64 @@ Fix (if needed):
 import { randomBytes } from "crypto";
 
 const shuffleSecure = <T>(array: T[]): T[] => {
-  const result = [...array];
+const result = [...array];
-  for (let i = result.length - 1; i > 0; i--) {
+for (let i = result.length - 1; i > 0; i--) {
-    // Use crypto.getRandomValues for better randomness
+// Use crypto.getRandomValues for better randomness
-    const rand = randomBytes(4).readUInt32LE(0);
+const rand = randomBytes(4).readUInt32LE(0);
-    const j = rand % (i + 1);
+const j = rand % (i + 1);
-    [result[i], result[j]] = [result[j], result[i]];
+[result[i], result[j]] = [result[j], result[i]];
-  }
+}
-  return result;
+return result;
 };
 
 Priority: 🟢 LOW — Document tradeoff and move on for now
 
-6. Test Coverage Gaps
+6.  Test Coverage Gaps
-File: gameService.test.ts
+    File: gameService.test.ts
-✅ Well Tested:
+    ✅ Well Tested:
 
-    Happy path: session creation, answer evaluation
+        Happy path: session creation, answer evaluation
-    Edge cases: duplicate distractors, empty results, invalid inputs
+        Edge cases: duplicate distractors, empty results, invalid inputs
-    Error propagation from DB layer
+        Error propagation from DB layer
 
 ❌ Missing Tests:
 
 // 1. Concurrency test (race condition)
 it("rejects duplicate answers for same question under concurrent load", async () => {
-  const session = await createGameSession(validRequest, store, "user-1");
+const session = await createGameSession(validRequest, store, "user-1");
-  const question = session.questions[0]!;
+const question = session.questions[0]!;
-  
+
-  // Submit two answers simultaneously
+// Submit two answers simultaneously
-  const [result1, result2] = await Promise.allSettled([
+const [result1, result2] = await Promise.allSettled([
-    evaluateAnswer({ sessionId, questionId, selectedOptionId: 0 }, store, "user-1"),
+evaluateAnswer({ sessionId, questionId, selectedOptionId: 0 }, store, "user-1"),
-    evaluateAnswer({ sessionId, questionId, selectedOptionId: 1 }, store, "user-1"),
+evaluateAnswer({ sessionId, questionId, selectedOptionId: 1 }, store, "user-1"),
-  ]);
+]);
-  
+
-  // Exactly one should succeed, one should throw ConflictError
+// Exactly one should succeed, one should throw ConflictError
-  expect([result1, result2].filter(r => r.status === "fulfilled")).toHaveLength(1);
+expect([result1, result2].filter(r => r.status === "fulfilled")).toHaveLength(1);
 });
 
 // 2. TTL expiration test
 it("deletes session after TTL expires", async () => {
-  vi.useFakeTimers();
+vi.useFakeTimers();
-  const session = await createGameSession(validRequest, store, "user-1");
+const session = await createGameSession(validRequest, store, "user-1");
-  
+
-  vi.advanceTimersByTime(31 * 60 * 1000); // 31 minutes
+vi.advanceTimersByTime(31 _ 60 _ 1000); // 31 minutes
-  
+
-  await expect(store.get(session.sessionId)).resolves.toBeNull();
+await expect(store.get(session.sessionId)).resolves.toBeNull();
 });
 
 // 3. Distractor fallback strategy test
 it("uses fallback when <3 unique distractors available", async () => {
-  mockGetDistractors.mockResolvedValue(["same", "same", "same", "same"]);
+mockGetDistractors.mockResolvedValue(["same", "same", "same", "same"]);
-  // Should either: (a) fetch from broader pool, or (b) reduce rounds gracefully
+// Should either: (a) fetch from broader pool, or (b) reduce rounds gracefully
 });
 
 Priority: 🟡 HIGH — Prevents regression on critical fixes
-🧼 Code Quality Nitpicks
+🧼 Code Quality Nitpicks 7. Magic Numbers
-7. Magic Numbers
 
 // gameService.ts:52
-await store.create(sessionId, {...}, 30 * 60 * 1000); // What is this?
+await store.create(sessionId, {...}, 30 _ 60 _ 1000); // What is this?
 
 // termModel.ts:65
 .limit(count); // count=6, but why?
@@ -267,16 +255,16 @@ optionId: z.number().int().min(0).max(3), // Why 4 options?
 
 Fix: Centralize in @lila/shared/constants.ts:
 
-export const GAME_SESSION_TTL_MS = 30 * 60 * 1000;
+export const GAME*SESSION_TTL_MS = 30 * 60 \_ 1000;
 export const DISTRACTOR_FETCH_COUNT = 6;
 export const GAME_OPTION_COUNT = 4;
 export const MIN_UNIQUE_DISTRACTORS = 3;
 
 8. Mutable Reference Leakage
-Location: InMemoryGameSessionStore.ts:get()
+   Location: InMemoryGameSessionStore.ts:get()
 
 get(sessionId: string): Promise<GameSessionData | null> {
-  return Promise.resolve(entry.data); // 🚩 Returns mutable reference to internal state
+return Promise.resolve(entry.data); // 🚩 Returns mutable reference to internal state
 }
 
 Risk: Any code that does session.answers.delete(...) mutates the store's internal Map directly.
@@ -291,37 +279,35 @@ return Promise.resolve(entry.data as Readonly<GameSessionData>);
 // Option C: Use immutable data structures (overkill for now)
 
 9. Zero Observability
-Problem: No logging, no metrics. You're flying blind in production.
+   Problem: No logging, no metrics. You're flying blind in production.
-Minimal Fix (5 minutes):
+   Minimal Fix (5 minutes):
-
-
 
 // apps/api/src/lib/logger.ts
 import pino from "pino";
-export const logger = pino({ 
+export const logger = pino({
-  level: process.env.LOG_LEVEL || "info",
+level: process.env.LOG_LEVEL || "info",
-  transport: process.env.NODE_ENV === "production" 
+transport: process.env.NODE_ENV === "production"
-    ? { target: "pino-pretty" } 
+? { target: "pino-pretty" }
-    : undefined 
+: undefined
 });
 
 // In gameService.ts:
 import { logger } from "../lib/logger.js";
 
 logger.info(
-  { userId, sourceLang, targetLang, termCount: terms.length },
+{ userId, sourceLang, targetLang, termCount: terms.length },
-  "game_session_created"
+"game_session_created"
 );
 
 logger.debug(
-  { sessionId, questionId, isCorrect, responseTimeMs },
+{ sessionId, questionId, isCorrect, responseTimeMs },
-  "answer_evaluated"
+"answer_evaluated"
 );
 
 Bonus: Export a Prometheus histogram for game_service_duration_seconds.
 
 10. ORDER BY RANDOM() Time Bomb
-Location: termModel.ts:getGameTerms() + getDistractors()
+    Location: termModel.ts:getGameTerms() + getDistractors()
 
 .orderBy(sql`RANDOM()`) // 🚩 Fine for 10k rows, slow for 1M
 
@@ -333,16 +319,16 @@ Reality Check: "Post-MVP" never comes without a ticket.
 Fix Options:
 
 -- Option A: Pre-computed random_seed column (updated nightly)
-WHERE ... AND random_seed >= random() 
+WHERE ... AND random_seed >= random()
-ORDER BY random_seed 
+ORDER BY random_seed
 LIMIT $1
 
 -- Option B: TABLESAMPLE for approximate sampling (Postgres 9.5+)
-FROM terms TABLESAMPLE SYSTEM(10) 
+FROM terms TABLESAMPLE SYSTEM(10)
-WHERE ... 
+WHERE ...
 LIMIT $1
 
 -- Option C: Random offset (simple, but still scans)
-OFFSET floor(random() * (SELECT count(*) FROM terms WHERE ...))
+OFFSET floor(random() _ (SELECT count(_) FROM terms WHERE ...))
 
-Action: Add a ticket to documentation/tickets/t00009.md now.
+Action: Add a ticket to documentation/tickets/t00009.md now.

documentation/tickets/t00006.md

@@ -84,7 +84,10 @@ Rejected because: for user-owned resources identified by opaque IDs, confirming
 2. `GameSessionStore.ts` — add `userId` to `GameSessionData`:
 
    ```ts
-   export type GameSessionData = { answers: Map<string, number>; userId: string };
+   export type GameSessionData = {
+     answers: Map<string, number>;
+     userId: string;
+   };
    ```
 
 3. `gameService.ts` — add `userId` to both function signatures:
@@ -100,7 +103,11 @@ Rejected because: for user-owned resources identified by opaque IDs, confirming
    Store it on create:
 
    ```ts
-   await store.create(sessionId, { answers: answerKey, userId }, 30 * 60 * 1000);
+   await store.create(
+     sessionId,
+     { answers: answerKey, userId },
+     30 * 60 * 1000,
+   );
    ```
 
    Assert on evaluate:
@@ -114,7 +121,7 @@ Rejected because: for user-owned resources identified by opaque IDs, confirming
 4. `gameController.ts` — extract from authenticated request:
 
    ```ts
-   req.session.user.id
+   req.session.user.id;
    ```
 
 5. `gameRouter.ts` — cast at registration:

documentation/tickets/t00008.md

@@ -27,7 +27,9 @@ Not chosen for this ticket — the database query is in `@lila/db` and is a sepa
 - Filter distractors against the correct answer before building options:
 
   ```ts
-  const uniqueDistractors = distractorTexts.filter((t) => t !== term.targetText);
+  const uniqueDistractors = distractorTexts.filter(
+    (t) => t !== term.targetText,
+  );
   const optionTexts = [term.targetText, ...uniqueDistractors.slice(0, 3)];
   ```