NF: assert_re_in helper to check if any line matches the re

Author: yarikoptic

nibabel/testing/__init__.py

@@ -9,6 +9,7 @@
 ''' Utilities for testing '''
 from __future__ import division, print_function
 
+import re
 import os
 import sys
 import warnings
@@ -59,6 +60,17 @@ def assert_allclose_safely(a, b, match_nans=True):
     assert_true(np.allclose(a, b))
 
 
+def assert_re_in(regex, c, flags=0):
+    """Assert that container (list, str, etc) contains entry matching the regex
+    """
+    if not isinstance(c, (list, tuple)):
+        c = [c]
+    for e in c:
+        if re.match(regex, e, flags=flags):
+            return
+    raise AssertionError("Not a single entry matched %r in %r" % (regex, c))
+
+
 def get_fresh_mod(mod_name=__name__):
     # Get this module, with warning registry empty
     my_mod = sys.modules[mod_name]

nibabel/tests/test_testing.py

@@ -10,7 +10,7 @@
 from nose.tools import assert_true, assert_equal, assert_raises
 from ..testing import (error_warnings, suppress_warnings,
                        clear_and_catch_warnings, assert_allclose_safely,
-                       get_fresh_mod)
+                       get_fresh_mod, assert_re_in)
 
 
 def assert_warn_len_equal(mod, n_in_context):
@@ -142,3 +142,24 @@ def f():
         with suppress_warnings():
             raise ValueError('An error')
     assert_raises(ValueError, f)
+
+
+def test_assert_re_in():
+    assert_re_in(".*", "")
+    assert_re_in(".*", ["any"])
+
+    # should do match not search
+    assert_re_in("ab", "abc")
+    assert_raises(AssertionError, assert_re_in, "ab", "cab")
+    assert_raises(AssertionError, assert_re_in, "ab$", "abc")
+
+    # Sufficient to have one entry matching
+    assert_re_in("ab", ["", "abc", "laskdjf"])
+    assert_raises(AssertionError, assert_re_in, "ab$", ["ddd", ""])
+
+    # Tuples should be ok too
+    assert_re_in("ab", ("", "abc", "laskdjf"))
+    assert_raises(AssertionError, assert_re_in, "ab$", ("ddd", ""))
+
+    # shouldn't "match" the emty list
+    assert_raises(AssertionError, assert_re_in, "", [])