Update the error message of download subcommand

onlinejudge_command/main.py

@@ -58,7 +58,8 @@ def run_program(args: argparse.Namespace, parser: argparse.ArgumentParser) -> in
 
     # TODO: make functions for subcommand take a named tuple instead of the raw result of argparse. Using named tuples make code well-typed.
     if args.subcommand in ['download', 'd', 'dl']:
-        subcommand_download.run(args)
+        if not subcommand_download.run(args):
+            return 1
     elif args.subcommand in ['login', 'l']:
         if not subcommand_login.run(args):
             return 1

onlinejudge_command/subcommand/download.py

@@ -75,7 +75,7 @@ def convert_sample_to_dict(sample: TestCase) -> Dict[str, str]:
     return data
 
 
-def run(args: argparse.Namespace) -> None:
+def run(args: argparse.Namespace) -> bool:
     # prepare values
     problem = dispatch.problem_from_url(args.url)
     if problem is None:
@@ -92,13 +92,21 @@ def run(args: argparse.Namespace) -> None:
     with utils.new_session_with_our_user_agent(path=args.cookie) as sess:
         if args.yukicoder_token and isinstance(problem, YukicoderProblem):
             sess.headers['Authorization'] = 'Bearer {}'.format(args.yukicoder_token)
-        if args.system:
-            samples = problem.download_system_cases(session=sess)
-        else:
-            samples = problem.download_sample_cases(session=sess)
+        try:
+            if args.system:
+                samples = problem.download_system_cases(session=sess)
+            else:
+                samples = problem.download_sample_cases(session=sess)
+        except requests.exceptions.HTTPError:
+            logger.exception('Failed to download test cases')
+            return False
+        except SampleParseError:
+            logger.exception('Failed to download test cases')
+            return False
 
     if not samples:
-        raise SampleParseError("Sample not found")
+        logger.error("Sample not found")
+        return False
 
     # append the history for submit subcommand
     if not args.dry_run and is_default_format:
@@ -127,7 +135,9 @@ def iterate_files_to_write(sample: TestCase, *, i: int) -> Iterator[Tuple[str, p
     for i, sample in enumerate(samples):
         for _, path, _ in iterate_files_to_write(sample, i=i):
             if path.exists():
-                raise FileExistsError('Failed to download since file already exists: ' + str(path))
+                logger.error('Failed to download since file already exists: %s', str(path))
+                logger.info(utils.HINT + 'We recommend adding your own test cases to test/ directory, and using one directory per one problem. Please see also https://github.com/online-judge-tools/oj/blob/master/docs/getting-started.md#random-testing. If you wanted to keep using one directory per one contest, you can run like `$ rm -rf test/ && oj d https://...`.')
+                return False
 
     # write samples to files
     for i, sample in enumerate(samples):
@@ -147,3 +157,5 @@ def iterate_files_to_write(sample: TestCase, *, i: int) -> Iterator[Tuple[str, p
     if args.log_file:
         with args.log_file.open(mode='w') as fhs:
             json.dump(list(map(convert_sample_to_dict, samples)), fhs)
+
+    return True