From 357a3fce679be657933715eef2fcbb9ba9ce0821 Mon Sep 17 00:00:00 2001
From: Gerald Schmittinger <gerald.schmittinger@ugent.be>
Date: Tue, 25 Feb 2025 00:39:24 +0100
Subject: [PATCH] Implemented mechanism to easily retrieve repositories.

---
 backend/src/data/repositories.ts               | 16 ++++++++++++++++
 backend/src/orm.ts                             | 11 +++++------
 backend/tests/data/users.test.ts               |  8 ++++----
 backend/tests/{testutils.ts => setup-tests.ts} |  2 +-
 4 files changed, 26 insertions(+), 11 deletions(-)
 create mode 100644 backend/src/data/repositories.ts
 rename backend/tests/{testutils.ts => setup-tests.ts} (76%)

diff --git a/backend/src/data/repositories.ts b/backend/src/data/repositories.ts
new file mode 100644
index 00000000..892e7ca3
--- /dev/null
+++ b/backend/src/data/repositories.ts
@@ -0,0 +1,16 @@
+import {AnyEntity, EntityName, EntityRepository} from "@mikro-orm/core";
+import {forkEntityManager} from "../orm";
+import {StudentRepository} from "./users/student-repository";
+import {Student} from "../entities/users/student.entity";
+
+function repositoryGetter<T extends AnyEntity, R extends EntityRepository<T>>(entity: EntityName<T>): () => R {
+    let cachedRepo: R | undefined;
+    return (): R => {
+        if (!cachedRepo) {
+            cachedRepo = forkEntityManager().getRepository(entity) as R;
+        }
+        return cachedRepo;
+    }
+}
+
+export const getStudentRepository = repositoryGetter<Student, StudentRepository>(Student);
diff --git a/backend/src/orm.ts b/backend/src/orm.ts
index 35110024..e31efc14 100644
--- a/backend/src/orm.ts
+++ b/backend/src/orm.ts
@@ -1,4 +1,4 @@
-import {AnyEntity, EntityName, EntityRepository, MikroORM} from '@mikro-orm/core';
+import { EntityManager, MikroORM} from '@mikro-orm/core';
 import config from './mikro-orm.config.js';
 import {EnvVars, getEnvVar} from "./util/envvars";
 
@@ -17,10 +17,9 @@ export async function initORM(testingMode: boolean = false) {
         }
     }
 }
-
-export function getRepository<T extends AnyEntity>(entityName: EntityName<T>): EntityRepository<T> {
-    if (orm === undefined) {
-        throw new Error("ORM is not initialized yet");
+export function forkEntityManager(): EntityManager {
+    if (!orm) {
+        throw Error("Accessing the Entity Manager before the ORM is fully initialized.")
     }
-    return orm.em.fork().getRepository(entityName);
+    return orm.em.fork();
 }
diff --git a/backend/tests/data/users.test.ts b/backend/tests/data/users.test.ts
index c201f36f..c806f13c 100644
--- a/backend/tests/data/users.test.ts
+++ b/backend/tests/data/users.test.ts
@@ -1,8 +1,8 @@
-import {initializeTests} from "../testutils"
+import {setupTestApp} from "../setup-tests"
 import {Student} from "../../src/entities/users/student.entity";
 import {describe, it, expect, beforeAll} from "vitest";
-import {getRepository} from "../../src/orm";
 import {StudentRepository} from "../../src/data/users/student-repository";
+import {getStudentRepository} from "../../src/data/repositories";
 
 const username = "teststudent";
 const firstName = "John";
@@ -11,8 +11,8 @@ describe("StudentRepository", () => {
     let studentRepository: StudentRepository;
 
     beforeAll(async () => {
-        await initializeTests()
-        studentRepository = getRepository(Student) as StudentRepository;
+        setupTestApp();
+        studentRepository = getStudentRepository();
     });
 
     it("should return the queried student after he was added", async () => {
diff --git a/backend/tests/testutils.ts b/backend/tests/setup-tests.ts
similarity index 76%
rename from backend/tests/testutils.ts
rename to backend/tests/setup-tests.ts
index af08b222..0fef6675 100644
--- a/backend/tests/testutils.ts
+++ b/backend/tests/setup-tests.ts
@@ -1,7 +1,7 @@
 import {initORM} from "../src/orm";
 import dotenv from "dotenv";
 
-export async function initializeTests() {
+export async function setupTestApp() {
     dotenv.config({path: ".env.test"});
     await initORM(true);
 }