No traceback on missing configuration with towncrier check (#501)

Author: chrysle

src/towncrier/_settings/load.py

@@ -13,6 +13,8 @@
 from pathlib import Path
 from typing import TYPE_CHECKING, Any, Mapping, Sequence
 
+from click import ClickException
+
 from .._settings import fragment_types as ft
 
 
@@ -60,7 +62,7 @@ class Config:
     orphan_prefix: str = "+"
 
 
-class ConfigError(Exception):
+class ConfigError(ClickException):
     def __init__(self, *args: str, **kwargs: str):
         self.failing_option = kwargs.get("failing_option")
         super().__init__(*args)

src/towncrier/newsfragments/501.feature

@@ -0,0 +1,3 @@
+Calling ``towncrier check`` without an existing configuration, will just show only an error message.
+
+In previous versions, a traceback was generated instead of the error message.

src/towncrier/test/test_settings.py

@@ -3,10 +3,12 @@
 
 import os
 
+from click.testing import CliRunner
 from twisted.trial.unittest import TestCase
 
 from .._settings import ConfigError, load_config
-from .helpers import write
+from .._shell import cli
+from .helpers import with_isolated_runner, write
 
 
 class TomlSettingsTests(TestCase):
@@ -192,6 +194,23 @@ def test_towncrier_toml_preferred(self):
         config = load_config(project_dir)
         self.assertEqual(config.package, "a")
 
+    @with_isolated_runner
+    def test_load_no_config(self, runner: CliRunner):
+        """
+        Calling the root CLI without an existing configuration file in the base directory,
+        will exit with code 1 and an informative message is sent to standard output.
+        """
+        temp = self.mktemp()
+        os.makedirs(temp)
+
+        result = runner.invoke(cli, ("--dir", temp))
+
+        self.assertEqual(
+            result.output,
+            f"No configuration file found.\nLooked in: {os.path.abspath(temp)}\n",
+        )
+        self.assertEqual(result.exit_code, 1)
+
     def test_missing_template(self):
         """
         Towncrier will raise an exception saying when it can't find a template.