✨(api) allow retrieving courses by their code as well as their pk

Richie knows the code but not the ID of courses.

src/backend/joanie/core/api/client.py

@@ -1,6 +1,8 @@
 """
 Client API endpoints
 """
+import uuid
+
 from django.db import IntegrityError, transaction
 from django.db.models import Count, OuterRef, Q, Subquery
 from django.http import HttpResponse
@@ -12,6 +14,7 @@
 from rest_framework.decorators import action
 from rest_framework.exceptions import NotFound
 from rest_framework.exceptions import ValidationError as DRFValidationError
+from rest_framework.generics import get_object_or_404
 from rest_framework.response import Response
 
 from joanie.core import enums, filters, models, permissions, serializers
@@ -629,24 +632,24 @@ class CourseAccessViewSet(
     """
     API ViewSet for all interactions with course accesses.
 
-    GET /api/courses/<course_id>/accesses/:<course_access_id>
+    GET /api/courses/<course_id|course_code>/accesses/:<course_access_id>
         Return list of all course accesses related to the logged-in user or one
         course access if an id is provided.
 
-    POST /api/courses/<course_id>/accesses/ with expected data:
+    POST /api/courses/<course_id|course_code>/accesses/ with expected data:
         - user: str
         - role: str [owner|admin|member]
         Return newly created course access
 
-    PUT /api/courses/<course_id>/accesses/<course_access_id>/ with expected data:
+    PUT /api/courses/<course_id|course_code>/accesses/<course_access_id>/ with expected data:
         - role: str [owner|admin|member]
         Return updated course access
 
-    PATCH /api/courses/<course_id>/accesses/<course_access_id>/ with expected data:
+    PATCH /api/courses/<course_id|course_code>/accesses/<course_access_id>/ with expected data:
         - role: str [owner|admin|member]
         Return partially updated course access
 
-    DELETE /api/courses/<course_id>/accesses/<course_access_id>/
+    DELETE /api/courses/<course_id|course_code>/accesses/<course_access_id>/
         Delete targeted course access
     """
 
@@ -702,16 +705,16 @@ class CourseViewSet(
     GET /api/courses/
         Return list of all courses related to the logged-in user.
 
-    GET /api/courses/:<course_id>
+    GET /api/courses/:<course_id|course_code>
         Return one course if an id is provided.
 
-    GET /api/courses/:<course_id>/wish
+    GET /api/courses/:<course_id|course_code>/wish
         Return wish status on this course for the authenticated user
 
-    POST /api/courses/:<course_id>/wish
+    POST /api/courses/:<course_id|course_code>/wish
         Confirm a wish on this course for the authenticated user
 
-    DELETE /api/courses/:<course_id>/wish
+    DELETE /api/courses/:<course_id|course_code>/wish
         Delete any existing wish on this course for the authenticated user
     """
 
@@ -723,6 +726,21 @@ class CourseViewSet(
     serializer_class = serializers.CourseSerializer
     ordering = ["-created_on"]
 
+    def get_object(self):
+        """Allow getting a course by its pk or by its code."""
+        queryset = self.filter_queryset(self.get_queryset())
+        try:
+            uuid.UUID(self.kwargs["pk"])
+        except ValueError:
+            filter_field = "code__iexact"
+        else:
+            filter_field = "pk"
+
+        obj = get_object_or_404(queryset, **{filter_field: self.kwargs["pk"]})
+        # May raise a permission denied
+        self.check_object_permissions(self.request, obj)
+        return obj
+
     def get_queryset(self):
         """
         Custom queryset to get user courses

src/backend/joanie/core/factories.py

@@ -116,7 +116,7 @@ class CourseFactory(factory.django.DjangoModelFactory):
     class Meta:
         model = models.Course
 
-    code = factory.Sequence(lambda n: n)
+    code = factory.Sequence(lambda n: f"{n:06d}")
     title = factory.Sequence(lambda n: f"Course {n}")
     cover = factory.django.ImageField(
         filename="cover.png", format="png", width=1, height=1

src/backend/joanie/tests/core/test_api_course.py

@@ -261,6 +261,37 @@ def test_api_course_get_authenticated_with_access(self, _):
             },
         )
 
+    @mock.patch.object(
+        fields.ThumbnailDetailField,
+        "to_representation",
+        return_value="_this_field_is_mocked",
+    )
+    def test_api_course_get_authenticated_by_code(self, _):
+        """
+        Authenticated users should be able to get a course through its code
+        if they have access to it.
+        """
+        user = factories.UserFactory()
+        token = self.get_user_token(user.username)
+
+        course = factories.CourseFactory(code="MYCODE-0088")
+        factories.UserCourseAccessFactory(user=user, course=course)
+        factories.CourseProductRelationFactory(
+            course=course,
+            product=factories.ProductFactory(),
+            organizations=[factories.OrganizationFactory()],
+        )
+
+        with self.assertNumQueries(10):
+            response = self.client.get(
+                "/api/v1.0/courses/mycode-0088/",
+                HTTP_AUTHORIZATION=f"Bearer {token}",
+            )
+
+        self.assertEqual(response.status_code, 200)
+        content = response.json()
+        self.assertEqual(content["id"], str(course.id))
+
     def test_api_course_create_anonymous(self):
         """
         Anonymous users should not be able to create a course.