Add regression test for language files

gooey/tests/test_language_parity.py

@@ -0,0 +1,41 @@
+import os
+import unittest
+import json
+from collections import OrderedDict
+from gooey import languages
+
+from gooey.gui.processor import ProcessController
+
+
+class TestLanguageParity(unittest.TestCase):
+    """
+    Checks that all language files have the same set of keys so that non-english
+    languages don't silently break as features are added to Gooey.
+    """
+
+    def test_languageParity(self):
+        langDir = os.path.dirname(languages.__file__)
+        englishFile = os.path.join(langDir, 'english.json')
+
+        english = self.readFile(englishFile)
+        jsonFiles = [(path, self.readFile(os.path.join(langDir, path)))
+                      for path in os.listdir(langDir)
+                      if path.endswith('json') and 'poooo' not in path and '2' not in path]
+
+        allKeys = set(english.keys())
+        for name, contents in jsonFiles:
+            missing = allKeys.difference(set(contents.keys()))
+            self.assertEqual(
+                set(),
+                missing,
+                "{} language file is missing keys: [{}]".format(name, missing)
+            )
+
+
+    def readFile(self, path):
+        with open(path, 'r', encoding='utf-8') as f:
+            return json.loads(f.read())
+
+
+if __name__ == '__main__':
+    unittest.main()