Added basic implentation for where

tests/core/test_SheerkaEvaluateConcept.py

@@ -18,7 +18,7 @@ class TestSheerkaEvaluateConcept(TestUsingMemoryBasedSheerka):
         ("True", True),
         ("1 > 2", False),
     ])
-    def test_i_can_evaluate_a_concept_with_simple_body(self,body, expected):
+    def test_i_can_evaluate_a_concept_with_simple_body(self, body, expected):
         sheerka = self.get_sheerka()
 
         concept = Concept("foo", body=body)
@@ -43,9 +43,9 @@ class TestSheerkaEvaluateConcept(TestUsingMemoryBasedSheerka):
         ("True", True),
         ("1 > 2", False),
     ])
-    def test_i_can_evaluate_the_other_metadata(self,expr, expected):
+    def test_i_can_evaluate_the_other_metadata(self, expr, expected):
         """
-        I only test WHERE, it's the same for the others
+        I only test PRE, it's the same for the others
         :param expr:
         :param expected:
         :return:
@@ -53,15 +53,15 @@ class TestSheerkaEvaluateConcept(TestUsingMemoryBasedSheerka):
 
         sheerka = self.get_sheerka()
 
-        concept = Concept("foo", where=expr)
+        concept = Concept("foo", pre=expr)
         evaluated = sheerka.evaluate_concept(self.get_context(sheerka), concept)
 
         assert evaluated.key == concept.key
         assert evaluated.metadata.body is None
-        assert evaluated.metadata.pre is None
+        assert evaluated.metadata.pre == expr
         assert evaluated.metadata.post is None
-        assert evaluated.metadata.where == expr
-        assert evaluated.get_metadata_value(ConceptParts.WHERE) == expected
+        assert evaluated.metadata.where is None
+        assert evaluated.get_metadata_value(ConceptParts.PRE) == expected
         assert evaluated.props == {}
         assert evaluated.metadata.is_evaluated
         assert len(evaluated.values) == 0 if expr is None else 1
@@ -330,3 +330,42 @@ class TestSheerkaEvaluateConcept(TestUsingMemoryBasedSheerka):
 
         assert evaluated.key == concept.init_key().key
 
+    @pytest.mark.parametrize("where_clause, expected", [
+        ("True", True),
+        ("False", False),
+        ("self < 10", False),
+        ("self < 11", True),
+        ("a < 20", False),
+        ("a > 19", True),
+        ("a + self > 20", True),
+    ])
+    def test_i_can_evaluate_simple_where(self, where_clause, expected):
+        sheerka = self.get_sheerka()
+
+        concept = Concept("foo", body="10", where=where_clause).def_prop("a", "20")
+        sheerka.add_in_cache(concept)
+
+        evaluated = sheerka.evaluate_concept(self.get_context(sheerka), concept)
+
+        if expected:
+            assert evaluated.key == concept.key
+        else:
+            assert sheerka.isinstance(evaluated, BuiltinConcepts.WHERE_CLAUSE_FAILED)
+            assert evaluated.body == concept
+
+    def test_i_can_evaluate_where_when_using_other_concept(self):
+        sheerka = self.get_sheerka()
+
+        foo_true = Concept("foo_true", body="True").init_key()
+        foo_false = Concept("foo_false", body="False").init_key()
+        sheerka.add_in_cache(foo_false)
+        sheerka.add_in_cache(foo_true)
+
+        concept = Concept("foo", where="foo_true").init_key()
+        evaluated = sheerka.evaluate_concept(self.get_context(sheerka), concept)
+        assert evaluated.key == concept.key
+
+        concept = Concept("foo", where="foo_false")
+        evaluated = sheerka.evaluate_concept(self.get_context(sheerka), concept)
+        assert sheerka.isinstance(evaluated, BuiltinConcepts.WHERE_CLAUSE_FAILED)
+        assert evaluated.body == concept