formatting

This commit is contained in:
lila 2026-04-30 01:20:12 +02:00
parent 35e54014b3
commit 4f47e18ad9
7 changed files with 119 additions and 124 deletions

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@ -1,6 +1,6 @@
# 🔥 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`
@ -52,8 +52,7 @@ interface GameSessionStore {
// Option B: Use Valkey Lua script for atomic read-modify-write
// Option C: Optimistic locking with version numbers
Priority: 🔴 CRITICAL — Data integrity issue
2. N+1 Query: Database Performance Bomb
Priority: 🔴 CRITICAL — Data integrity issue 2. N+1 Query: Database Performance Bomb
Location: gameService.ts:24-26 + termModel.ts:getDistractors()
// For each of N terms, we call getDistractors():
@ -65,24 +64,16 @@ const questions: GameQuestion[] = await Promise.all(
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:
@ -97,13 +88,13 @@ Fix: Batch Fetch Distractors
const allDistractors = await db
.select({ termId: terms.id, text: translations.text })
.from(terms)
.innerJoin(translations, /* ... */)
.innerJoin(translations, /_ ... _/)
.where(and(
eq(terms.pos, pos),
eq(translations.difficulty, difficulty),
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);
@ -134,8 +125,7 @@ if (uniqueDistractors.length < 3) {
);
}
Priority: 🟡 HIGH — Observability & UX issue
⚠️ High-Severity Smells
4. Code Duplication: Singleplayer vs Multiplayer
⚠️ High-Severity Smells 4. Code Duplication: Singleplayer vs Multiplayer
Compare: gameService.ts vs multiplayerGameService.ts
// gameService.ts
const optionTexts = [term.targetText, ...uniqueDistractors.slice(0, 3)];
@ -172,13 +162,12 @@ export const buildQuestionOptions = (
};
};
Priority: 🟡 HIGH — Maintainability issue
5. Shuffle Bias: Math.random() Trap
Priority: 🟡 HIGH — Maintainability issue 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--) {
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
// ...
}
};
@ -241,7 +230,7 @@ it("deletes session after TTL expires", async () => {
vi.useFakeTimers();
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();
});
@ -253,11 +242,10 @@ it("uses fallback when <3 unique distractors available", async () => {
});
Priority: 🟡 HIGH — Prevents regression on critical fixes
🧼 Code Quality Nitpicks
7. Magic Numbers
🧼 Code Quality Nitpicks 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?
@ -267,7 +255,7 @@ 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;
@ -294,8 +282,6 @@ return Promise.resolve(entry.data as Readonly<GameSessionData>);
Problem: No logging, no metrics. You're flying blind in production.
Minimal Fix (5 minutes):
// apps/api/src/lib/logger.ts
import pino from "pino";
export const logger = pino({
@ -343,6 +329,6 @@ 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.

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@ -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:

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@ -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)];
```