fix: allow same mentor in different courses

server/vbv_lernwelt/learning_mentor/migrations/0005_alter_learningmentor_mentor.py

@@ -0,0 +1,22 @@
+# Generated by Django 3.2.20 on 2024-02-12 09:25
+
+import django.db.models.deletion
+from django.conf import settings
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+    dependencies = [
+        migrations.swappable_dependency(settings.AUTH_USER_MODEL),
+        ("learning_mentor", "0004_alter_mentorinvitation_unique_together"),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name="learningmentor",
+            name="mentor",
+            field=models.ForeignKey(
+                on_delete=django.db.models.deletion.CASCADE, to=settings.AUTH_USER_MODEL
+            ),
+        ),
+    ]

server/vbv_lernwelt/learning_mentor/models.py

@@ -8,7 +8,7 @@ from vbv_lernwelt.course.models import CourseSessionUser
 
 
 class LearningMentor(models.Model):
-    mentor = models.OneToOneField(User, on_delete=models.CASCADE)
+    mentor = models.ForeignKey(User, on_delete=models.CASCADE)
     course = models.ForeignKey("course.Course", on_delete=models.CASCADE)
 
     participants = models.ManyToManyField(

server/vbv_lernwelt/learning_mentor/tests/test_mentor.py

@@ -232,3 +232,15 @@ class LearningMentorAPITest(APITestCase):
         self.assertFalse(
             LearningMentor.objects.filter(participants=participant_cs_user).exists()
         )
+
+    def test_mentor_multiple_courses(self) -> None:
+        # GIVEN
+        course_a, _ = create_course("Course A")
+        course_b, _ = create_course("Course B")
+
+        # WHEN
+        LearningMentor.objects.create(mentor=self.mentor, course=course_a)
+        LearningMentor.objects.create(mentor=self.mentor, course=course_b)
+
+        # THEN
+        self.assertEqual(LearningMentor.objects.count(), 2)