Add None type to expressions (#101)

Expressions can now contain None values.
e.g. variable is None

2 files changed, 47 insertions, 1 deletions

diff --git a/peekaboo/ruleset/expressions.py b/peekaboo/ruleset/expressions.py
index e4fe0ad..c08bb58 100644
--- a/peekaboo/ruleset/expressions.py
+++ b/peekaboo/ruleset/expressions.py
@@ -101,6 +101,13 @@ class EvalBoolean(EvalBase):
         self.value = self.token == "True"
 
 
+class EvalNone(EvalBase):
+    """ Class to evaluate a parsed none constant """
+    def convert(self):
+        logger.debug("None: %s", self.value)
+        self.value = None
+
+
 class EvalInteger(EvalBase):
     """ Class to evaluate a parsed integer constant """
     def convert(self):
@@ -447,6 +454,7 @@ class ExpressionParser(object):
         ParserElement.enablePackrat()
 
         boolean = Keyword('True') | Keyword('False')
+        none = Keyword('None')
         integer = Word(nums)
         real = Combine(Word(nums) + "." + Word(nums))
         string = (QuotedString('"', escChar='\\')
@@ -458,7 +466,7 @@ class ExpressionParser(object):
         ])
         result = (Keyword('bad') | Keyword('fail') | Keyword('good')
                   | Keyword('ignore') | Keyword('unknown'))
-        rval = boolean | real | integer | string | regex | result | dereference
+        rval = boolean | none | real | integer | string | regex | result | dereference
         rvallist = Group(Suppress('[') + delimitedList(rval) + Suppress(']'))
         rvalset = Group(Suppress('{') + delimitedList(rval) + Suppress('}'))
         operand = rval | rvallist | rvalset
@@ -466,6 +474,7 @@ class ExpressionParser(object):
         # parse actions replace the parsed tokens with an instantiated object
         # which we can later call into for evaluation of its content
         boolean.setParseAction(EvalBoolean)
+        none.setParseAction(EvalNone)
         integer.setParseAction(EvalInteger)
         real.setParseAction(EvalReal)
         string.setParseAction(EvalString)
diff --git a/tests/test.py b/tests/test.py
index 151bc19..bec3d97 100755
--- a/tests/test.py
+++ b/tests/test.py
@@ -822,6 +822,43 @@ unknown : baz'''
         result = rule.evaluate(sample)
         self.assertEqual(result.result, Result.unknown)
 
+    def test_rule_ignore_no_name_declared(self):
+        """ Test rule to ignore file with no name_declared. """
+        config = '''[expressions]
+            expression.3  : not sample.name_declared -> ignore
+        '''
+
+        factory = CreatingSampleFactory(
+            cuckoo=None, base_dir="",
+            job_hash_regex="", keep_mail_data=False,
+            processing_info_dir=None)
+
+        part = {"full_name": "file1.gif",
+                "name_declared": "file1.gif",
+                "type_declared": "image/gif"
+               }
+
+        sample = factory.create_sample('file1.gif', 'GIF87...', metainfo=part)
+        rule = ExpressionRule(CreatingConfigParser(config))
+        result = rule.evaluate(sample)
+        self.assertEqual(result.result, Result.unknown)
+
+        sample = factory.create_sample('file2.gif', 'GIF87...')
+        sample.meta_info_name_declared = None
+        rule = ExpressionRule(CreatingConfigParser(config))
+        result = rule.evaluate(sample)
+        self.assertEqual(result.result, Result.ignored)
+
+        config = '''[expressions]
+            expression.3  : sample.name_declared is None -> ignore
+        '''
+
+        sample = factory.create_sample('file2.gif', 'GIF87...')
+        sample.meta_info_name_declared = None
+        rule = ExpressionRule(CreatingConfigParser(config))
+        result = rule.evaluate(sample)
+        self.assertEqual(result.result, Result.ignored)
+
     def test_rule_ignore_mail_signatures(self):
         """ Test rule to ignore cryptographic mail signatures. """
         config = '''[expressions]