fix: Fix Question Service seed-batch bugs and edge cases

.github/workflows/docker-build-push.yml

@@ -21,7 +21,7 @@ jobs:
           # Add one entry per microservice
           - name: matching-ui
             context: ./ui-services/matching-ui-service
-          - name: questions-ui
+          - name: question-ui
             context: ./ui-services/question-ui-service
           - name: collab-ui
             context: ./ui-services/collab-ui-service

.github/workflows/format-lint.yml

@@ -67,7 +67,7 @@ jobs:
           npx eslint --format json . > eslint-report.json
           cat eslint-report.json | reviewdog -f=eslint -name="eslint" -reporter=github-pr-review -level=error
 
-  questions-ui-lint:
+  question-ui-lint:
     runs-on: ubuntu-latest
     steps:
       - name: Set REVIEWDOG_GITHUB_API_TOKEN
@@ -100,7 +100,7 @@ jobs:
           eslint_exit_code=$exit_code
 
           if [ $eslint_exit_code -ne 0 ]; then
-            echo "ESLint failed for questions-ui"
+            echo "ESLint failed for question-ui"
             exit 1
           fi
 
@@ -180,7 +180,7 @@ jobs:
           eslint_exit_code=$exit_code
 
           if [ $eslint_exit_code -ne 0 ]; then
-            echo "ESLint failed for questions-ui"
+            echo "ESLint failed for question-ui"
             exit 1
           fi
 

.github/workflows/leetcode-update.yml

@@ -48,7 +48,7 @@ jobs:
         run: |
           echo "Waiting for leetcode-backend to respond..."
           for i in {1..60}; do
-            code=$(curl -s -o /dev/null -w "%{http_code}" http://localhost:5285/api/v1/leetcode/health || true)
+            code=$(curl -s -o /dev/null -w "%{http_code}" http://localhost:5285/api/v1/leetcode-service/health || true)
             if [ "$code" = "200" ]; then
               echo "Leetcode backend is ready (HTTP 200)"
               exit 0
@@ -73,7 +73,7 @@ jobs:
         run: |
           echo "Waiting for question-backend to respond..."
           for i in {1..60}; do
-            code=$(curl -s -o /dev/null -w "%{http_code}" http://localhost:5275/api/v1/questions/health || true)
+            code=$(curl -s -o /dev/null -w "%{http_code}" http://localhost:5275/api/v1/question-service/health || true)
             if [ "$code" = "200" ]; then
               echo "Question backend is ready (HTTP 200)"
               exit 0

backend-services/leetcode-backend-service/.env.example

@@ -1,6 +1,6 @@
 MONGODB_URI=mongodb+srv://admin:<db-password>@cluster3219.ll0nzkk.mongodb.net/?retryWrites=true&w=majority&appName=Cluster3219
 ADMIN_TOKEN=<db-password>
-QUESTION_API_URL=http://question-backend:5275/api/v1/questions
+QUESTION_API_URL=http://localhost:5275/api/v1/question-service
 # Maximum number of concurrent LeetCode detail fetches.
 # Optional: defaults to 6 if not set.
-LEETCODE_DETAIL_CONCURRENCY=6
+LEETCODE_DETAIL_CONCURRENCY=6

backend-services/leetcode-backend-service/README.md

@@ -49,13 +49,13 @@ Server listening on http://localhost:5285
 **Note**: Local development (e.g. `npm run dev`) is possible (though not recommended). To enable it, update the .env file by changing:
 
 ```bash
-QUESTION_API_URL=http://question-backend:5275/api/v1/questions
+QUESTION_API_URL=http://question-backend:5275/api/v1/question-service
 ```
 
 to:
 
 ```bash
-QUESTION_API_URL=http://localhost:5275/api/v1/questions
+QUESTION_API_URL=http://localhost:5275/api/v1/question-service
 ```
 
 Do change the `QUESTION_API_URL` back when using docker run.
@@ -86,19 +86,19 @@ src/
 
 ## API
 
-Base URL: `http://localhost:5285/api/v1`
+Base URL: `http://localhost:5285/api/v1/leetcode-service`
 
 ### Seed 200 problems into Mongo
 
-**POST** `/leetcode/seed-batch`  
+**POST** `/seed-batch`  
 Fetches the next 200 problems and **upserts** to Mongo.
 
 Examples:
 
 ```bash
 # Replace ADMIN_TOKEN with DB password
 # MUSt run the question-service before running the follow command
-curl.exe --request POST -H "X-Admin-Token: <>" --url "http://localhost:5285/api/v1/leetcode/seed-batch"
+curl.exe --request POST -H "X-Admin-Token: <ADMIN_TOKEN>" --url "http://localhost:5285/api/v1/leetcode-service/seed-batch"
 ```
 
 ## Data Model

backend-services/leetcode-backend-service/src/db/changeStream.ts

@@ -91,18 +91,15 @@ export default fp((app: FastifyInstance) => {
           const doc = change.fullDocument as QuestionDoc;
           if (!doc) continue;
           await postDoc(doc);
-          app.log.info({ doc }, "Got changed document:");
+          logger.info("Got changed document:", { doc });
         } catch (err) {
-          app.log.error(
-            { err },
-            "[ChangeStream] Error processing change event",
-          );
+          logger.error("[ChangeStream] Error processing change event", { err });
         }
       }
       isProcessing = false;
     }
     changeStream.on("change", (change: ChangeStreamDocument) => {
-      app.log.info("[ChangeStream] Event");
+      logger.info("[ChangeStream] Event");
       changeQueue.push(change);
       void processQueue();
     });

backend-services/leetcode-backend-service/src/db/connection.ts

@@ -16,16 +16,21 @@ export default fp(async (app: FastifyInstance) => {
   const uri = process.env.MONGODB_URI;
   if (!uri) throw new Error("MONGODB_URI is missing");
 
-  if (
-    mongoose.connection.readyState === mongoose.ConnectionStates.disconnected
-  ) {
-    await mongoose.connect(uri, {
-      dbName: "leetcode-service",
-      serverSelectionTimeoutMS: 10000,
-    });
+  if (mongoose.connection.readyState !== mongoose.ConnectionStates.connected) {
+    try {
+      await mongoose.connect(uri, {
+        dbName: "leetcode-service",
+        serverSelectionTimeoutMS: 10000,
+      });
+      logger.info("[Mongo] Connected");
+    } catch (err) {
+      logger.error("[Mongo] Connection failed: ", err);
+      throw err;
+    }
+  } else {
+    logger.info("[Mongo] Already connected");
   }
 
-  logger.info("Mongo connected");
   app.decorate("mongo", mongoose);
 
   app.addHook("onClose", async () => {

backend-services/leetcode-backend-service/src/db/model/question.ts

@@ -42,6 +42,7 @@ const QuestionSchema = new Schema<QuestionDoc>(
   { collection: "questions", timestamps: true },
 );
 
+// Compound indexes for faster queries
 QuestionSchema.index({
   source: 1,
   titleSlug: 1,
@@ -54,7 +55,6 @@ const CursorSchema = new mongoose.Schema(
     _id: { type: String, required: true },
     nextSkip: { type: Number, default: 0, index: true },
     pageSize: { type: Number, default: 200 },
-    done: { type: Boolean, default: false },
     lastRunAt: { type: Date },
     total: { type: Number, default: 0 },
   },

backend-services/leetcode-backend-service/src/db/types/seedBatchResponse.ts

@@ -2,7 +2,6 @@ export interface SeedBatchResponse {
   ok: boolean;
   message: string;
   nextSkip: number;
-  done: boolean;
   // keep room for extra fields
   [k: string]: unknown;
 }

backend-services/leetcode-backend-service/src/health.ts

@@ -0,0 +1,66 @@
+import { setTimeout as delay } from "node:timers/promises";
+
+type HealthOpts = {
+  url?: string; // health check URL
+  timeoutMs?: number; // per-attempt timeout
+  retries?: number; // number of retries after the first attempt
+};
+
+interface HealthResponse {
+  ok?: boolean;
+}
+
+const BATCH_HEALTH_TIMEOUT_MS = 1500;
+const BATCH_HEALTH_RETRIES = 2;
+const BASE_DELAY_MS = 250;
+
+/** Check the health of the question service.
+ * Throws an error if the service is unhealthy or unreachable after retries.
+ * @param opts - Options for health check.
+ * @returns A promise that resolves to true if healthy, otherwise throws an error.
+ */
+
+export async function checkQuestionServiceHealth({
+  url = `${process.env.QUESTION_API_URL}/health`,
+  timeoutMs = BATCH_HEALTH_TIMEOUT_MS,
+  retries = BATCH_HEALTH_RETRIES,
+}: HealthOpts = {}) {
+  if (!process.env.QUESTION_API_URL)
+    throw new Error("QUESTION_API_URL is not set");
+
+  let lastErr: unknown;
+
+  // Attempt health check with retries where retries is the number of additional attempts after the first
+  for (let attempt = 0; attempt < retries + 1; attempt++) {
+    const controller = new AbortController();
+    const t = setTimeout(() => controller.abort(), timeoutMs);
+
+    try {
+      const res = await fetch(url, {
+        method: "GET",
+        headers: { accept: "application/json" },
+        signal: controller.signal,
+      });
+      clearTimeout(t);
+
+      if (!res.ok) {
+        lastErr = new Error(`Health endpoint returned ${res.status}`);
+      } else {
+        const body: HealthResponse = (await res.json()) as HealthResponse;
+        if (body?.ok !== true) {
+          lastErr = new Error("Health endpoint did not return ok=true");
+        } else {
+          return true;
+        }
+      }
+    } catch (err) {
+      lastErr = err;
+    }
+
+    if (attempt < retries) {
+      await delay(BASE_DELAY_MS * 2 ** attempt);
+    }
+  }
+
+  throw new Error(`Question service health check failed: ${String(lastErr)}`);
+}