# HG changeset patch
# User Boris Feld <boris.feld@octobus.net>
# Date 2018-02-09 11:48:12
# Node ID 04304b779df1251a4e6a6711fa52e40b88b86573
# Parent  eefb5d603482ae88c2d9cb75676ec1d2deae1b52

tests: raise a better error when patterns are wrongly formatted

It is fairly easy to make mistakes when merging conflict in the pattern file.
A common mistake is to forget adding an extra trailing comma changing the
length of the tuple.

We now detect such error and raise a better error message that helps to find
it.

diff --git a/tests/run-tests.py b/tests/run-tests.py
--- a/tests/run-tests.py
+++ b/tests/run-tests.py
@@ -990,7 +990,12 @@ class Test(unittest.TestCase):
                 # the intermediate 'compile' step help with debugging
                 code = compile(source.read(), replacementfile, 'exec')
                 exec(code, data)
-                r.extend(data.get('substitutions', ()))
+                for value in data.get('substitutions', ()):
+                    if len(value) != 2:
+                        msg = 'malformatted substitution in %s: %r'
+                        msg %= (replacementfile, value)
+                        raise ValueError(msg)
+                    r.append(value)
         return r
 
     def _escapepath(self, p):