add support for testing paths are not redirected

Add support for tests that ensure no existing rule redirects by having
the test assume a response code of 200.

Change-Id: I2aa1ada7e85c5e8066fdae634a4cf38b64ec821b
Signed-off-by: Doug Hellmann <doug@doughellmann.com>

doc/source/user/index.rst

@@ -37,6 +37,9 @@ parts: the input path, the expected HTTP response code, and the
    /no/rule 301 /should/fail
    /nova/latest/man/nova-cert.html 410
 
+   # verify that this path is not redirected
+   /pike/index.html 200
+
 The output from ``whereto`` includes a report of any tests that do not
 match, including if no rules match and if multiple rules match. For
 example:

whereto/app.py

@@ -78,7 +78,11 @@ def process_tests(ruleset, tests, max_hops):
     for test in tests:
         matches = _find_matches(ruleset, test)
         if not matches:
-            # No rules matched at all.
+            # No rules matched at all. If the test was expecting
+            # that don't record it as a failure.
+            if test[2] == '200':
+                used.add(test[0])
+            else:
                 mismatches.append((test, []))
         else:
             code, expected = test[-2:]

whereto/tests/test_app.py

@@ -173,3 +173,34 @@ class TestProcessTests(base.TestCase):
             {1, 2, 3},
         )
         self.assertEqual(expected, actual)
+
+    def test_200_test(self):
+        self.ruleset.add(
+            1,
+            'redirect', '301', '/path', '/new/path',
+        )
+        actual = app.process_tests(
+            self.ruleset,
+            [(1, '/another/path', '200', None)],
+            0,
+        )
+        expected = ([], [], [], set())
+        self.assertEqual(expected, actual)
+
+    def test_200_test_rule_mismatch(self):
+        self.ruleset.add(
+            1,
+            'redirect', '301', '/path', '/new/path',
+        )
+        actual = app.process_tests(
+            self.ruleset,
+            [(1, '/path', '200', None)],
+            0,
+        )
+        expected = (
+            [((1, '/path', '200', None), [(1, '301', '/new/path')])],
+            [],
+            [],
+            {1},
+        )
+        self.assertEqual(expected, actual)

whereto/tests/test_parser.py

@@ -114,3 +114,12 @@ class TestParseTests(base.TestCase):
             [(2, ['/releases', '410', None])],
             self.parse(input),
         )
+
+    def test_200_rule(self):
+        input = u"""
+        /releases 200
+        """
+        self.assertEqual(
+            [(2, ['/releases', '200', None])],
+            self.parse(input),
+        )