Add match() and _match() class methods to rule classes

Add match() and _match() class methods to rule classes:
- _match() returns a regex match object for the given raw_rule
- match() converts the _match() result to True or False

The primary usage is to get an answer to the question "is this raw_rule
your job?". (For a moment, I thought about naming the function
*Rule.myjob() instead of *Rule.match() ;-)

My next patch will change aa.py to use *Rule.match() instead of directly
using RE_*, which will make the import list much shorter and hide
another implementation detail inside the rule classes.

Also change _parse() to use _match() instead of the regex, and add some
tests for match() and _match().


Acked-by: Seth Arnold <seth.arnold@canonical.com>

utils/test/test-capability.py

@@ -30,6 +30,7 @@ class CapabilityTest(unittest.TestCase):
 
         obj = CapabilityRule.parse(rawrule)
 
+        self.assertTrue(CapabilityRule.match(rawrule))
         self.assertEqual(rawrule.strip(), obj.raw_rule)
 
         self._compare_obj(obj, expected)
@@ -220,6 +221,7 @@ class InvalidCapabilityTest(unittest.TestCase):
         with self.assertRaises(AppArmorException):
             obj = CapabilityRule(CapabilityRule.parse(rawrule))
 
+        self.assertFalse(CapabilityRule.match(rawrule))
         self.assertIsNone(obj, 'CapbilityRule handed back an object unexpectedly')
 
     def test_invalid_cap_missing_comma(self):
@@ -269,6 +271,7 @@ class WriteCapabilityTest(unittest.TestCase):
         clean = obj.get_clean()
         raw = obj.get_raw()
 
+        self.assertTrue(CapabilityRule.match(rawrule))
         self.assertEqual(cleanrule.strip(), clean, 'unexpected clean rule')
         self.assertEqual(rawrule.strip(), raw, 'unexpected raw rule')
 
@@ -294,12 +297,15 @@ class CapabilityCoveredTest(unittest.TestCase):
         self.maxDiff = None
 
     def _is_covered(self, obj, rule_to_test):
+        self.assertTrue(CapabilityRule.match(rule_to_test))
         return obj.is_covered(CapabilityRule.parse(rule_to_test))
 
     def _is_covered_exact(self, obj, rule_to_test):
+        self.assertTrue(CapabilityRule.match(rule_to_test))
         return obj.is_covered(CapabilityRule.parse(rule_to_test), True, True)
 
     def _is_equal(self, obj, rule_to_test, strict):
+        self.assertTrue(CapabilityRule.match(rule_to_test))
         return obj.is_equal(CapabilityRule.parse(rule_to_test), strict)
 
     def test_covered_single(self):