tests: Test error output from msodde

tests/msodde/test_basic.py

@@ -10,10 +10,14 @@
 
 import unittest
 from oletools import msodde
-from tests.test_utils import DATA_BASE_DIR as BASE_DIR
+from tests.test_utils import SOURCE_BASE_DIR, DATA_BASE_DIR as BASE_DIR
 import os
 from os.path import join
 from traceback import print_exc
+from subprocess import check_output, CalledProcessError
+import sys
+import json
+from collections import OrderedDict
 
 
 class TestReturnCode(unittest.TestCase):
@@ -88,6 +92,36 @@ def do_test_validity(self, args, expect_error=False):
                              .format(args, expect_error, have_exception))
 
 
+class TestErrorOutput(unittest.TestCase):
+    """msodde does not specify error by return code but text output."""
+
+    def test_crypt_output(self):
+        """Check for helpful error message when failing to decrypt."""
+        env = os.environ
+        try:
+            env['PYTHONPATH'] = SOURCE_BASE_DIR + os.pathsep + \
+                                os.environ['PYTHONPATH']
+        except KeyError:
+            env['PYTHONPATH'] = SOURCE_BASE_DIR
+
+        for suffix in 'doc', 'docm', 'docx', 'ppt', 'pptm', 'pptx', 'xls', \
+                'xlsb', 'xlsm', 'xlsx':
+            example_file = join(BASE_DIR, 'encrypted', 'encrypted.' + suffix)
+            try:
+                output = check_output([sys.executable, '-m', 'msodde', '-j',
+                                       example_file],
+                                      universal_newlines=True, env=env)
+                self.fail('Should have returned non-zero exit code!')
+            except CalledProcessError as err:
+                output = err.output
+            data = json.loads(output, object_pairs_hook=OrderedDict)
+            # debug: json.dump(data, sys.stdout, indent=4)
+            self.assertTrue(all(part['type'] == 'msg' for part in data))
+            self.assertTrue(any(part['level'] == 'ERROR' and
+                                'passwords could not decrypt' in part['msg']
+                                for part in data))
+
+
 class TestDdeLinks(unittest.TestCase):
     """ capture output of msodde and check dde-links are found correctly """