Make sure unit tests can be run from outside the package

The cards from usr/share are not accessible when running the tests from
a temporary directory. This happens for instance when running

  $ pybuild --test --test-pytest

Make sure that this command would succeed by mocking the calls to open.

Signed-off-by: Olivier Gayot <olivier.gayot@sigexec.com>

1 files changed, 17 insertions, 10 deletions

diff --git a/tests/test_cards.py b/tests/test_cards.py
index a5e4437..73f42a0 100644
--- a/tests/test_cards.py
+++ b/tests/test_cards.py
@@ -1,19 +1,26 @@
+import json
 import unittest
+from unittest.mock import patch, mock_open
 
 from swiftstory.cards import Cards
 
 
 class TestCards(unittest.TestCase):
-    def test_get_cards_fr(self):
-        self.assertTrue(Cards.get_white_cards("fr"))
-        self.assertTrue(Cards.get_black_cards("fr"))
+    def test_get_cards_supported_language(self):
+        white_cards = json.dumps([
+            "White Card 1", "White Card 2",
+            "White Card 3", "White Card 4",
+        ])
+        black_cards = json.dumps(["Black Card 1", "Black Card 2"])
 
-    def test_get_cards_en(self):
-        self.assertTrue(Cards.get_white_cards("en"))
-        self.assertTrue(Cards.get_black_cards("en"))
+        with patch("swiftstory.cards.open", mock_open(read_data=white_cards)):
+            self.assertIn("White Card 2", Cards.get_white_cards("en"))
+        with patch("swiftstory.cards.open", mock_open(read_data=black_cards)):
+            self.assertIn("Black Card 1", Cards.get_black_cards("en"))
 
     def test_get_cards_unknown_language(self):
-        with self.assertRaises(FileNotFoundError):
-            Cards.get_white_cards("zz")
-        with self.assertRaises(FileNotFoundError):
-            Cards.get_black_cards("zz")
+        with patch("swiftstory.cards.open", side_effect=FileNotFoundError):
+            with self.assertRaises(FileNotFoundError):
+                Cards.get_white_cards("zz")
+            with self.assertRaises(FileNotFoundError):
+                Cards.get_black_cards("zz")