diff --git a/src/crud/courseprogress.py b/src/crud/courseprogress.py
index 4818f1e..66eda01 100644
--- a/src/crud/courseprogress.py
+++ b/src/crud/courseprogress.py
@@ -1,6 +1,7 @@
 from sqlalchemy.orm import Session
+from fastapi import HTTPException
 
-from src.enums import CourseEnum, course_enum_list
+from src.enums import CourseEnum
 from src.models import CourseProgress, User
 from src.schemas.courseprogress import CourseProgressBase
 
@@ -41,13 +42,19 @@ def get_course_progress(db: Session, user: User, course: CourseEnum):
 
 def initialize_user(db: Session, user: User):
     """Create CourseProgress records with a value of 0 for a new user"""
-    for course in course_enum_list:
-        db.add(CourseProgress(progress_value=0.0, course=course, owner_id=user.user_id))
-        db.commit()
+    for course in CourseEnum:
+        if course != CourseEnum.All:
+            db.add(
+                CourseProgress(progress_value=0.0, course=course, owner_id=user.user_id)
+            )
+            db.commit()
 
 
 def patch_course_progress(db: Session, user: User, course_progress: CourseProgressBase):
     """Change the progress value for a given course"""
+    if course_progress.progress_value > 1 or course_progress.progress_value < 0:
+        raise HTTPException(status_code=400, detail="Invalid progress value")
+
     db_course_progress_list = []
     if course_progress.course != CourseEnum.All:
         db_course_progress_list = (
@@ -64,7 +71,12 @@ def patch_course_progress(db: Session, user: User, course_progress: CourseProgre
             .filter(CourseProgress.owner_id == user.user_id)
             .all()
         )
-
+    print(f"LENGTH OF LIST OF {course_progress.course}: {len(db_course_progress_list)}")
     for db_course_progress in db_course_progress_list:
         db_course_progress.progress_value = course_progress.progress_value
         db.commit()
+
+    return [
+        CourseProgressBase(course=db_cp.course, progress_value=db_cp.progress_value)
+        for db_cp in db_course_progress_list
+    ]
diff --git a/src/enums.py b/src/enums.py
index 3b6ecd4..3ec4085 100644
--- a/src/enums.py
+++ b/src/enums.py
@@ -34,15 +34,3 @@ class CourseEnum(StrEnum):
     Colors = "Colors"
     FruitsVegetables = "FruitsVegetables"
     All = "All"
-
-
-# This is needed because for some reason iterating over an enum doesn't work properly...
-course_enum_list = [
-    CourseEnum.Fingerspelling,
-    # CourseEnum.Basics,
-    CourseEnum.Hobbies,
-    CourseEnum.Animals,
-    CourseEnum.Colors,
-    CourseEnum.FruitsVegetables,
-    CourseEnum.All,
-]
diff --git a/src/main.py b/src/main.py
index d518c4e..71cf170 100644
--- a/src/main.py
+++ b/src/main.py
@@ -92,7 +92,7 @@ async def get_course_progress(
     return crud_courseprogress.get_course_progress(db, current_user, course)
 
 
-@app.patch("/courseprogress")
+@app.patch("/courseprogress", response_model=List[courseprogress.CourseProgressBase])
 async def patch_course_progress(
     course_progress: courseprogress.CourseProgressBase,
     current_user_name: str = Depends(crud_authentication.get_current_user_name),
diff --git a/tests/test_authentication.py b/tests/test_authentication.py
new file mode 100644
index 0000000..825d73e
--- /dev/null
+++ b/tests/test_authentication.py
@@ -0,0 +1,139 @@
+import sys
+
+import pytest
+from fastapi.testclient import TestClient
+
+sys.path.append("..")
+
+from src.main import app, get_db
+from tests.config.database import clear_db, override_get_db
+
+app.dependency_overrides[get_db] = override_get_db
+
+client = TestClient(app)
+
+username1 = "user1"
+username2 = "user2"
+password = "password"
+avatar = "lion"
+
+
+@pytest.mark.asyncio
+async def test_register():
+    """LEAVE THIS TEST AT THE TOP OF THE FILE!"""
+    """Test the register endpoint"""
+    clear_db()
+
+    response = client.post(
+        "/register",
+        headers={"Content-Type": "application/json"},
+        json={"username": username1, "password": password, "avatar": avatar},
+    )
+
+    assert response.status_code == 200
+    assert len(response.json()["access_token"]) > 0
+
+
+@pytest.mark.asyncio
+async def test_register_duplicate_name_should_fail():
+    """Test whether registering a user with an existing username fails"""
+    response = client.post(
+        "/register",
+        headers={"Content-Type": "application/json"},
+        json={"username": username1, "password": password, "avatar": avatar},
+    )
+
+    assert response.status_code == 400
+    assert "access_token" not in response.json()
+
+
+@pytest.mark.asyncio
+async def test_register_without_username_should_fail():
+    """Test whether registering a user without passing a username fails"""
+    response = client.post(
+        "/register",
+        headers={"Content-Type": "application/json"},
+        json={"password": password, "avatar": avatar},
+    )
+
+    assert response.status_code == 422
+    assert "access_token" not in response.json()
+
+
+@pytest.mark.asyncio
+async def test_register_without_password_should_fail():
+    """Test whether registering a user without passing a password fails"""
+    response = client.post(
+        "/register",
+        headers={"Content-Type": "application/json"},
+        json={"username": username2, "avatar": avatar},
+    )
+
+    assert response.status_code == 422
+    assert "access_token" not in response.json()
+
+
+@pytest.mark.asyncio
+async def test_register_without_avatar_should_fail():
+    """Test whether registering a user without passing an avatar fails"""
+    response = client.post(
+        "/register",
+        headers={"Content-Type": "application/json"},
+        json={"username": username2, "password": password},
+    )
+
+    # Not ideal that this is 400 instead of 422, but had no other choice than to give this field a default value
+    assert response.status_code == 400
+    assert "access_token" not in response.json()
+
+
+@pytest.mark.asyncio
+async def test_login():
+    """Test the login endpoint"""
+    response = client.post(
+        "/login",
+        headers={"Content-Type": "application/json"},
+        json={"username": username1, "password": password},
+    )
+
+    assert response.status_code == 200
+    assert len(response.json()["access_token"]) > 0
+
+
+@pytest.mark.asyncio
+async def test_login_wrong_password_should_fail():
+    wrong_password = password + "extra characters"
+    response = client.post(
+        "/login",
+        headers={"Content-Type": "application/json"},
+        json={"username": username1, "password": wrong_password},
+    )
+
+    assert response.status_code == 401
+    assert "access_token" not in response.json()
+
+
+@pytest.mark.asyncio
+async def test_login_without_username_should_fail():
+    """Test whether logging in without passing a username fails"""
+    response = client.post(
+        "/login",
+        headers={"Content-Type": "application/json"},
+        json={"username": username1},
+    )
+
+    assert response.status_code == 422
+    assert "access_token" not in response.json()
+
+
+@pytest.mark.asyncio
+async def test_login_without_password_should_fail():
+    """Test whether logging in without passing a password fails"""
+    response = client.post(
+        "/login",
+        headers={"Content-Type": "application/json"},
+        json={"username": username1},
+    )
+
+    assert response.status_code == 422
+    assert "access_token" not in response.json()
diff --git a/tests/test_courseprogress.py b/tests/test_courseprogress.py
new file mode 100644
index 0000000..ec41d56
--- /dev/null
+++ b/tests/test_courseprogress.py
@@ -0,0 +1,174 @@
+import random
+import sys
+
+import pytest
+from fastapi.testclient import TestClient
+
+sys.path.append("..")
+
+from src.enums import CourseEnum
+from src.main import app, get_db
+from tests.config.database import clear_db, override_get_db
+
+app.dependency_overrides[get_db] = override_get_db
+
+client = TestClient(app)
+
+username = "user1"
+password = "password"
+avatar = "lion"
+
+
+async def register_user():
+    response = client.post(
+        "/register",
+        headers={"Content-Type": "application/json"},
+        json={"username": username, "password": password, "avatar": avatar},
+    )
+
+    assert response.status_code == 200
+
+    return response.json()["access_token"]
+
+
+@pytest.mark.asyncio
+async def test_register_creates_progress_of_zero():
+    """Test whether registering a new user initializes all progress values to 0.0"""
+    clear_db()
+
+    token = await register_user()
+    headers = {"Authorization": f"Bearer {token}", "Content-Type": "application/json"}
+
+    for course in CourseEnum:
+        if course != CourseEnum.All:
+            response = client.get(f"/courseprogress/{course}", headers=headers)
+            assert response.status_code == 200
+
+            response = response.json()[0]
+
+            assert response["progress_value"] == 0.0
+            assert response["course"] == course
+
+
+@pytest.mark.asyncio
+async def test_get_all_returns_all():
+    clear_db()
+    token = await register_user()
+
+    headers = {"Authorization": f"Bearer {token}", "Content-Type": "application/json"}
+    response = client.get("/courseprogress/All", headers=headers)
+
+    assert response.status_code == 200
+    response = response.json()
+
+    for course in CourseEnum:
+        if course != CourseEnum.All:
+            assert {"progress_value": 0.0, "course": course} in response
+
+
+@pytest.mark.asyncio
+async def test_get_nonexisting_course_should_fail():
+    clear_db()
+    token = await register_user()
+
+    fake_course = "FakeCourse"
+
+    headers = {"Authorization": f"Bearer {token}", "Content-Type": "application/json"}
+    response = client.get(f"/courseprogress/{fake_course}", headers=headers)
+
+    assert response.status_code == 422
+
+
+@pytest.mark.asyncio
+async def test_patch_course_progress():
+    clear_db()
+    token = await register_user()
+
+    headers = {"Authorization": f"Bearer {token}", "Content-Type": "application/json"}
+
+    for course in CourseEnum:
+        if course != CourseEnum.All:
+            progress_value = random.uniform(0, 1)
+
+            response = client.patch(
+                f"/courseprogress",
+                headers=headers,
+                json={"progress_value": progress_value, "course": course},
+            )
+
+            assert response.status_code == 200
+            assert response.json()[0]["progress_value"] == progress_value
+
+
+@pytest.mark.asyncio
+async def test_patch_all_should_patch_all_courses():
+    clear_db()
+    token = await register_user()
+
+    headers = {"Authorization": f"Bearer {token}", "Content-Type": "application/json"}
+
+    progress_value = random.uniform(0, 1)
+
+    response = client.patch(
+        f"/courseprogress",
+        headers=headers,
+        json={"progress_value": progress_value, "course": "All"},
+    )
+
+    assert response.status_code == 200
+
+    response = client.get("/courseprogress/All", headers=headers)
+
+    assert response.status_code == 200
+    response = response.json()
+
+    for course in CourseEnum:
+        if course != CourseEnum.All:
+            assert {"progress_value": progress_value, "course": course} in response
+
+
+@pytest.mark.asyncio
+async def test_patch_nonexisting_course_should_fail():
+    clear_db()
+    token = await register_user()
+
+    fake_course = "FakeCourse"
+
+    headers = {"Authorization": f"Bearer {token}", "Content-Type": "application/json"}
+
+    progress_value = random.uniform(0, 1)
+
+    response = client.patch(
+        f"/courseprogress",
+        headers=headers,
+        json={"progress_value": progress_value, "course": fake_course},
+    )
+
+    assert response.status_code == 422
+
+
+@pytest.mark.asyncio
+async def test_patch_course_with_invalid_value_should_fail():
+    clear_db()
+    token = await register_user()
+
+    headers = {"Authorization": f"Bearer {token}", "Content-Type": "application/json"}
+
+    too_high_progress_value = random.uniform(0, 1) + 2
+    too_low_progress_value = random.uniform(0, 1) - 2
+
+    response = client.patch(
+        f"/courseprogress",
+        headers=headers,
+        json={"progress_value": too_high_progress_value, "course": "All"},
+    )
+
+    assert response.status_code == 400
+
+    response = client.patch(
+        f"/courseprogress",
+        headers=headers,
+        json={"progress_value": too_low_progress_value, "course": "All"},
+    )
+
+    assert response.status_code == 400
diff --git a/tests/test_highscores.py b/tests/test_highscores.py
new file mode 100644
index 0000000..5e145a4
--- /dev/null
+++ b/tests/test_highscores.py
@@ -0,0 +1,17 @@
+import sys
+
+import pytest
+from fastapi.testclient import TestClient
+
+sys.path.append("..")
+
+from src.main import app, get_db
+from tests.config.database import clear_db, override_get_db
+
+app.dependency_overrides[get_db] = override_get_db
+
+client = TestClient(app)
+
+username = "user1"
+password = "password"
+avatar = "lion"