move is_file_limitation_rule() to the rules module (Rule class)

capa/capabilities/common.py

@@ -11,7 +11,7 @@ import itertools
 import collections
 from typing import Any, Tuple
 
-from capa.rules import Rule, Scope, RuleSet
+from capa.rules import Scope, RuleSet
 from capa.engine import FeatureSet, MatchResults
 from capa.features.address import NO_ADDRESS
 from capa.features.extractors.base_extractor import FeatureExtractor, StaticFeatureExtractor, DynamicFeatureExtractor
@@ -40,12 +40,8 @@ def find_file_capabilities(ruleset: RuleSet, extractor: FeatureExtractor, functi
     return matches, len(file_features)
 
 
-def is_file_limitation_rule(rule: Rule) -> bool:
-    return rule.meta.get("namespace", "") == "internal/limitation/file"
-
-
 def has_file_limitation(rules: RuleSet, capabilities: MatchResults, is_standalone=True) -> bool:
-    file_limitation_rules = list(filter(is_file_limitation_rule, rules.rules.values()))
+    file_limitation_rules = list(filter(lambda r: r.is_file_limitation_rule(), rules.rules.values()))
 
     for file_limitation_rule in file_limitation_rules:
         if file_limitation_rule.name not in capabilities:

capa/main.py

@@ -140,10 +140,6 @@ def has_rule_with_namespace(rules: RuleSet, capabilities: MatchResults, namespac
     )
 
 
-def is_internal_rule(rule: Rule) -> bool:
-    return rule.meta.get("namespace", "").startswith("internal/")
-
-
 def is_supported_format(sample: Path) -> bool:
     """
     Return if this is a supported file based on magic header values

capa/rules/__init__.py

@@ -869,6 +869,12 @@ class Rule:
             for child in statement.get_children():
                 yield from self._extract_subscope_rules_rec(child)
 
+    def is_internal_rule(self) -> bool:
+        return self.meta.get("namespace", "").startswith("internal/")
+
+    def is_file_limitation_rule(self) -> bool:
+        return self.meta.get("namespace", "") == "internal/limitation/file"
+
     def is_subscope_rule(self):
         return bool(self.meta.get("capa/subscope-rule", False))