From b21f207b4f2bdf170d08c5d5fda6c77fa9b20abc Mon Sep 17 00:00:00 2001
From: Finn-Thorben Sell <dev@finn-thorben.me>
Date: Thu, 24 Mar 2022 17:07:16 +0100
Subject: [PATCH] add tests for error handling

---
 configurations/errors.py     |  2 +-
 tests/test_error_handling.py | 43 ++++++++++++++++++++++++++++++++++++
 2 files changed, 44 insertions(+), 1 deletion(-)
 create mode 100644 tests/test_error_handling.py

diff --git a/configurations/errors.py b/configurations/errors.py
index 1f4a984..b339801 100644
--- a/configurations/errors.py
+++ b/configurations/errors.py
@@ -4,7 +4,7 @@ import sys
 import os
 
 if TYPE_CHECKING:
-    from .values import Value
+    from .values import Value   # pragma: no cover
 
 
 class TermStyles:
diff --git a/tests/test_error_handling.py b/tests/test_error_handling.py
new file mode 100644
index 0000000..7f5d0ff
--- /dev/null
+++ b/tests/test_error_handling.py
@@ -0,0 +1,43 @@
+import io
+from unittest.mock import patch
+
+from django.test import TestCase
+
+from configurations.errors import ValueRetrievalError, SetupError, with_error_handler
+from configurations.values import Value
+
+
+class ErrorHandlingTestCase(TestCase):
+    def test_help_text_in_explanation_lines(self):
+        value_instance = Value(help_text="THIS IS A TEST")
+        exception = ValueRetrievalError(value_instance)
+        self.assertIn("Help: THIS IS A TEST", exception.explanation_lines)
+
+    def test_help_reference_in_explanation_lines(self):
+        value_instance = Value(help_reference="https://example.com")
+        exception = ValueRetrievalError(value_instance)
+        self.assertIn("Reference: https://example.com", exception.explanation_lines)
+
+    def test_example_in_explanation_lines(self):
+        value_instance = Value(example_generator=lambda: "test")
+        exception = ValueRetrievalError(value_instance)
+        self.assertIn("Example value: 'test'", exception.explanation_lines)
+
+    def test_error_handler_rendering(self):
+        # setup
+        with patch("configurations.errors.sys.stderr", new=io.StringIO()) as mock:
+            def inner():
+                try:
+                    value_instance = Value(environ_required=True)
+                    value_instance.setup("TEST")
+                except ValueRetrievalError as err:
+                    raise SetupError("This is a test exception", [err])
+
+            # execution
+            with_error_handler(inner)()
+
+            # verification
+            self.assertEqual(mock.getvalue().strip(),
+                             "This is a test exception\n"
+                             "    * Value of TEST could not be retrieved from environment\n"
+                             "        - TEST is taken from the environment variable DJANGO_TEST as a Value")