Require a robot.py file in the archive

Fixes #9.

Author: PeterJCLaw

code_submitter/server.py

@@ -83,10 +83,18 @@ async def upload(request: Request) -> Response:
         )
 
     try:
-        zipfile.ZipFile(io.BytesIO(contents))
+        zf = zipfile.ZipFile(io.BytesIO(contents))
     except zipfile.BadZipFile:
         return Response("Must upload a ZIP file", status_code=400)
 
+    try:
+        zf.getinfo('robot.py')
+    except KeyError:
+        return Response(
+            "ZIP file must contain a 'robot.py' at the root",
+            status_code=400,
+        )
+
     archive_id = await database.execute(
         Archive.insert().values(
             content=contents,

tests/tests_app.py

@@ -277,3 +277,24 @@ def test_upload_bad_file(self) -> None:
             self.database.fetch_all(ChoiceHistory.select()),
         )
         self.assertEqual([], choices, "Should not have created a choice")
+
+    def test_upload_archive_without_robot_py(self) -> None:
+        contents = io.BytesIO()
+        with zipfile.ZipFile(contents, mode='w') as zip_file:
+            zip_file.writestr('main.py', 'print("I am a robot")')
+
+        response = self.session.post(
+            self.url_path_for('upload'),
+            files={'archive': ('whatever.zip', contents.getvalue(), 'application/zip')},
+        )
+        self.assertEqual(400, response.status_code)
+
+        archives = self.await_(
+            self.database.fetch_all(Archive.select()),
+        )
+        self.assertEqual([], archives, "Wrong content stored in the database")
+
+        choices = self.await_(
+            self.database.fetch_all(ChoiceHistory.select()),
+        )
+        self.assertEqual([], choices, "Should not have created a choice")