Fix enrollment count query to include all courses on page, not just the first

[Levi-Ojukwu]

Summary

Fix enrolledCount in course listings returning 0 for every course except the first one on the page.

Problem

In CourseService.listCourses, the enrollment count query used eq(enrollments.courseId, courseIds[0]) which only filtered for the first course ID. All other courses on the page received an enrollment count of 0.

Fix

Replaced eq(enrollments.courseId, courseIds[0]) with inArray(enrollments.courseId, courseIds) so the query fetches enrollment counts for all courses on the current page in a single query.
File changed: src/modules/courses/course.service.ts — added inArray import and updated the .where() clause.

Closes #26

[DeFiVC]

PR Review: Fix enrollment count query to include all courses on page

Author: Levi-Ojukwu (Ojukwu_Levi) | Closes: #26 | State: OPEN | Mergeable: MERGEABLE

Review Checklist

Item	Status
Git Identity	✅ DeFiVC defivc1@email.com
Linked Issue	✅ Closes #26 — matches requirements exactly
Code Quality	✅ Correct and minimal fix
CI Status	✅ Lint & Typecheck: SUCCESS, Test: SUCCESS
Merge Conflicts	✅ None

Code Analysis

src/modules/courses/course.service.ts (2 additions, 2 deletions):

1. Line 1: Added inArray to the drizzle-orm import — correct
2. Line 50: Changed eq(enrollments.courseId, courseIds[0]) to inArray(enrollments.courseId, courseIds) — correct

This is a clean, minimal fix that exactly addresses the issue. The original code was filtering enrollments using only the first course ID in the array, causing all other courses to show an enrollment count of 0. The fix uses inArray to query for all course IDs on the current page in a single query.

Decision: APPROVE

The PR is a correct, minimal bug fix that exactly matches the issue requirements. CI is green, no merge conflicts. This is ready to merge.