def _check_arcs(self, a1, a2, arc_type):
"""Check that the arc lists `a1` and `a2` are equal.
If they are equal, return empty string. If they are unequal, return
a string explaining what is different.
"""
# Make them into multi-line strings so we can see what's going wrong.
s1 = arcs_to_arcz_repr(a1)
s2 = arcs_to_arcz_repr(a2)
if s1 != s2:
lines1 = s1.splitlines(True)
lines2 = s2.splitlines(True)
diff = "".join(difflib.ndiff(lines1, lines2))
return "\n" + arc_type + " arcs differ: minus is expected, plus is actual\n" + diff
else:
return ""
def test_arcs_to_arcz_repr(arcs, arcz_repr):
assert arcs_to_arcz_repr(arcs) == arcz_repr
def assert_equal_arcs(self, a1, a2, msg=None):
"""Assert that the arc lists `a1` and `a2` are equal."""
# Make them into multi-line strings so we can see what's going wrong.
s1 = arcs_to_arcz_repr(a1)
s2 = arcs_to_arcz_repr(a2)
self.assertMultiLineEqual(s1, s2, msg)
