fix(commands/check): Show warning if no commit to check when running cz check --rev-range

#165

Author: Lee-W

commitizen/commands/check.py

@@ -1,10 +1,11 @@
 import os
 import re
+import warnings
 from typing import Dict, Optional
 
 from commitizen import factory, git, out
 from commitizen.config import BaseConfig
-from commitizen.error_codes import INVALID_COMMIT_MSG
+from commitizen.error_codes import INVALID_COMMIT_MSG, NO_COMMITS_FOUND
 
 
 class Check:
@@ -50,6 +51,10 @@ def __call__(self):
 
         """
         commit_msgs = self._get_commit_messages()
+        if not commit_msgs:
+            warnings.warn(f"No commit found with range: '{self.rev_range}'")
+            raise SystemExit(NO_COMMITS_FOUND)
+
         pattern = self.cz.schema_pattern()
         for commit_msg in commit_msgs:
             if not Check.validate_commit_message(commit_msg, pattern):

tests/commands/test_check_command.py

@@ -194,3 +194,11 @@ def test_check_command_with_invalid_argment(args, config, capsys):
         commands.Check(config=config, arguments=args)
     _, err = capsys.readouterr()
     assert "One and only one argument is required for check command!" in err
+
+
+def test_check_command_with_empty_range(config, mocker, capsys):
+    check_cmd = commands.Check(config=config, arguments={"rev_range": "master..master"})
+    with pytest.raises(SystemExit), pytest.warns(UserWarning) as record:
+        check_cmd()
+
+    assert record[0].message.args[0] == "No commit found with range: 'master..master'"