Raises error if no sample found.

onlinejudge/_implementation/command/download.py

@@ -44,6 +44,9 @@ def download(args: 'argparse.Namespace') -> None:
         else:
             samples = problem.download_sample_cases(session=sess)
 
+    if not samples:
+        raise onlinejudge.type.SampleParseError("Sample not found")
+
     # append the history for submit command
     if not args.dry_run and is_default_format:
         history = onlinejudge._implementation.download_history.DownloadHistory()

tests/command_download_invalid.py

@@ -3,6 +3,8 @@
 import requests.exceptions
 import tests.command_download
 
+from onlinejudge.type import SampleParseError
+
 
 class DownloadInvalid(unittest.TestCase):
     def snippet_call_download_raises(self, *args, **kwargs):
@@ -14,6 +16,10 @@ def snippet_call_download_twice(self, *args, **kwargs):
     def test_call_download_invalid(self):
         self.snippet_call_download_raises(requests.exceptions.InvalidURL, 'https://not_exist_contest.jp/tasks/001_a')
 
+    def test_call_download_no_sample_found(self):
+        self.snippet_call_download_raises(SampleParseError, 'https://atcoder.jp/contests/tenka1-2013-quala/tasks/tenka1_2013_qualA_a')
+        self.snippet_call_download_raises(SampleParseError, 'https://open.kattis.com/problems/hello')
+
     def test_call_download_twice(self):
         self.snippet_call_download_twice('https://atcoder.jp/contests/abc114/tasks/abc114_c', 'https://atcoder.jp/contests/abc003/tasks/abc003_4', [
             {

tests/command_download_kattis.py

@@ -29,7 +29,3 @@ def test_call_download_kattis_hanoi18_a(self):
                 "output": "YES\nRRUULLD\nNO\nYES\nRD\n"
             },
         ], type='json')
-
-    def test_call_download_kattis_hello(self):
-        # there is no sample cases (and no samples.zip; it returns 404)
-        self.snippet_call_download('https://open.kattis.com/problems/hello', [], type='json')