refactor: derive cohort endDate dynamically from weeks

migrations/1775842011163-migrations.ts

@@ -0,0 +1,26 @@
+import { MigrationInterface, QueryRunner } from 'typeorm';
+
+export class Migrations1775842011163 implements MigrationInterface {
+    name = 'Migrations1775842011163';
+
+    public async up(queryRunner: QueryRunner): Promise<void> {
+        await queryRunner.query(`ALTER TABLE "cohort" DROP COLUMN "endDate"`);
+    }
+
+    public async down(queryRunner: QueryRunner): Promise<void> {
+        await queryRunner.query(
+            `ALTER TABLE "cohort" ADD "endDate" TIMESTAMP WITH TIME ZONE`,
+        );
+        await queryRunner.query(`
+            UPDATE "cohort" c
+            SET "endDate" = (
+                SELECT MAX(cw."scheduledDate")
+                FROM "cohort_week" cw
+                WHERE cw."cohortId" = c."id"
+            )
+        `);
+        await queryRunner.query(
+            `ALTER TABLE "cohort" ALTER COLUMN "endDate" SET NOT NULL`,
+        );
+    }
+}

src/certificates/certificates-generation.service.ts

@@ -154,7 +154,7 @@ export class CertificatesGenerationService {
             certificate.name,
             certificate.cohort.type,
             certificate.type,
-            certificate.cohort.endDate,
+            certificate.cohort.getEndDate(),
             certificate.withExercises,
             certificate.rank,
         );

src/certificates/certificates.service.ts

@@ -50,13 +50,14 @@ export class CertificatesService {
     ): Promise<{ cohort: Cohort; certificateEntities: Certificate[] }> {
         const cohort = await this.cohortRepository.findOne({
             where: { id: cohortId },
+            relations: { weeks: true },
         });
 
         if (!cohort) {
             throw new ServiceError(`Cohort with id ${cohortId} not found`);
         }
 
-        if (cohort.endDate > new Date()) {
+        if (cohort.getEndDate() > new Date()) {
             throw new BadRequestException(
                 `Cohort with id ${cohortId} has not ended yet. Certificates can only be generated after the cohort ends.`,
             );
@@ -212,7 +213,7 @@ export class CertificatesService {
 
         const certificates = await this.certificateRepository.find({
             where: { cohort: { id: cohortId } },
-            relations: { cohort: true, user: true },
+            relations: { cohort: { weeks: true }, user: true },
         });
 
         if (certificates.length === 0) {
@@ -279,7 +280,7 @@ export class CertificatesService {
         const certificate = await this.certificateRepository.findOne({
             where: { id },
             relations: {
-                cohort: true,
+                cohort: { weeks: true },
                 user: true,
             },
         });
@@ -310,7 +311,7 @@ export class CertificatesService {
     }> {
         const certificates = await this.certificateRepository.find({
             where: { cohort: { id: cohortId } },
-            relations: { cohort: true, user: true },
+            relations: { cohort: { weeks: true }, user: true },
         });
 
         if (certificates.length === 0) {

src/cohorts/cohort-reminder.service.ts

@@ -185,7 +185,7 @@
 
         const cohort = await this.cohortRepository.findOne({
             where: { id: cohortId },
-            relations: { users: true },
+            relations: { users: true, weeks: true },
         });
 
         if (!cohort) {
@@ -234,7 +234,7 @@
                         user.discordUserName;
 
                     await this.mailService.sendCohortFeedbackReminderEmail(
                         user.email!,
                         userName,
                         cohortName,
                         season,
@@ -271,7 +271,7 @@
         const nextExecuteOnTime = new Date(task.executeOnTime);
         nextExecuteOnTime.setUTCDate(nextExecuteOnTime.getUTCDate() + 7);
 
-        const cutoffDate = new Date(cohort.endDate);
+        const cutoffDate = new Date(cohort.getEndDate());
         cutoffDate.setUTCDate(cutoffDate.getUTCDate() + 7);
 
         if (nextExecuteOnTime <= cutoffDate) {

src/cohorts/cohorts.response.dto.ts

@@ -56,7 +56,7 @@ export class GetCohortResponseDto {
             type: cohort.type,
             season: cohort.season,
             startDate: cohort.startDate.toISOString(),
-            endDate: cohort.endDate.toISOString(),
+            endDate: cohort.getEndDate().toISOString(),
             registrationDeadline: cohort.registrationDeadline.toISOString(),
             hasExercises: cohort.hasExercises,
             classroomId: cohort.classroomId ?? null,

src/cohorts/cohorts.service.ts

@@ -161,7 +161,7 @@ export class CohortsService {
                             type: cohort.type,
                             season: cohort.season,
                             startDate: cohort.startDate.toISOString(),
-                            endDate: cohort.endDate.toISOString(),
+                            endDate: cohort.getEndDate().toISOString(),
                             registrationDeadline:
                                 cohort.registrationDeadline.toISOString(),
                         }),
@@ -189,6 +189,7 @@ export class CohortsService {
     async listPublicCohorts(): Promise<ListAvailableCohortsResponseDto> {
         const latestCohorts = await this.cohortRepository
             .createQueryBuilder('c')
+            .leftJoinAndSelect('c.weeks', 'weeks')
             .distinctOn(['c.type'])
             .orderBy('c.type', 'ASC')
             .addOrderBy('c.season', 'DESC')
@@ -303,7 +304,6 @@ export class CohortsService {
                 cohort.type = cohortData.type;
                 cohort.season = season;
                 cohort.startDate = startDate;
-                cohort.endDate = endDate;
                 cohort.registrationDeadline = registrationDeadline;
                 cohort.hasExercises = hasExercises;
                 cohort.weeks = [];
@@ -411,12 +411,6 @@ export class CohortsService {
             const startDate = new Date(cohortData.startDate);
             startDate.setUTCHours(0, 0, 0, 0);
             cohort.startDate = startDate;
-
-            const config = this.cohortConfigService.getConfig(cohort.type);
-            const totalWeeks = config.gdSessions + 2;
-            const endDate = new Date(startDate);
-            endDate.setUTCDate(endDate.getUTCDate() + totalWeeks * 7);
-            cohort.endDate = endDate;
         }
         if (cohortData.registrationDeadline) {
             const registrationDeadline = new Date(

src/entities/cohort.entity.ts

@@ -34,15 +34,20 @@ export class Cohort extends BaseEntity {
     @Column('timestamptz')
     startDate!: Date;
 
-    @Column('timestamptz')
-    endDate!: Date;
-
     @Column('boolean')
     hasExercises!: boolean;
 
     @Column('text', { nullable: true })
     classroomId!: string | null;
 
+    getEndDate(): Date {
+        return this.weeks.reduce(
+            (max, week) =>
+                week.scheduledDate > max ? week.scheduledDate : max,
+            this.weeks[0].scheduledDate,
+        );
+    }
+
     @ManyToMany(() => User, (u) => u.cohorts)
     @JoinTable()
     users!: User[];

src/github-classroom/github-classroom.service.ts

@@ -84,7 +84,7 @@ export class GitHubClassroomService {
         }
 
         const endDatePlusBuffer = new Date(
-            cohort.endDate.getTime() + TWENTY_FOUR_HOURS_MS,
+            cohort.getEndDate().getTime() + TWENTY_FOUR_HOURS_MS,
         );
         const hasCohortEnded = endDatePlusBuffer < new Date();