Fixed variable recognition when it is a concept

tests/parsers/test_BaseNodeParser.py

@@ -1,6 +1,6 @@
 import pytest
 from core.concept import Concept
-from parsers.BaseNodeParser import BaseNodeParser
+from parsers.BaseNodeParser import BaseNodeParser, NoFirstTokenError
 from parsers.BnfNodeParser import StrMatch, Sequence, OrderedChoice, Optional, ZeroOrMore, OneOrMore, ConceptExpression
 
 from tests.TestUsingMemoryBasedSheerka import TestUsingMemoryBasedSheerka
@@ -115,6 +115,13 @@ class TestBaseNodeParser(TestUsingMemoryBasedSheerka):
             "qux": ["1005"],
         }
 
+    def test_i_cannot_get_concept_by_first_keyword_when_no_first_keyword(self):
+        sheerka, context, foo = self.init_concepts(Concept("x y", body="x y").def_var("x").def_var("y"))
+        res = BaseNodeParser.get_concepts_by_first_token(context, [foo])
+
+        assert not res.status
+        assert res.body == NoFirstTokenError(foo, foo.key)
+
     def test_i_can_resolve_concepts_by_first_keyword(self):
         sheerka, context, *updated = self.init_concepts(
             "one",