[tor-commits] [ooni-probe/master] Test that specific Failures are caught before parent Failures

[art at torproject.org]

commit 7284fac63bd5100700319ba655f5a2c335193a1b
Author: srvetus <srvetus at users.noreply.github.com>
Date:   Thu Nov 19 14:16:42 2015 +0100

    Test that specific Failures are caught before parent Failures
---
 ooni/tests/test_errors.py |   20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/ooni/tests/test_errors.py b/ooni/tests/test_errors.py
new file mode 100644
index 0000000..7baa1ea
--- /dev/null
+++ b/ooni/tests/test_errors.py
@@ -0,0 +1,20 @@
+from twisted.trial import unittest
+
+import ooni.errors
+
+class TestErrors(unittest.TestCase):
+
+    def test_catch_child_failures_before_parent_failures(self):
+        """
+        Verify that more specific Failures are caught first by
+        handleAllFailures() and failureToString().
+
+        Fails if a subclass is listed after it's parent Failure.
+        """
+
+        # Check each Failure against all subsequent failures
+        for index, (failure, _) in enumerate(ooni.errors.known_failures):
+            for sub_failure, _ in ooni.errors.known_failures[index+1:]:
+
+                # Fail if subsequent Failure inherits from the current Failure
+                self.assertNotIsInstance(sub_failure(None), failure)