Enhanced complex concepts handling

tests/test_sheerka.py

@@ -144,7 +144,7 @@ def test_i_can_get_a_builtin_concept_by_their_enum_or_the_string():
         assert sheerka.get(str(key)) is not None
 
 
-def test_i_can_get_new_concept():
+def test_i_can_get_a_newly_created_concept():
     sheerka = get_sheerka()
     concept = get_default_concept()
 
@@ -324,6 +324,21 @@ def test_i_can_instantiate_a_concept():
     assert new.props["b"].value == "value"
 
 
+def test_i_can_instantiate_with_the_name_and_the_id():
+    sheerka = get_sheerka()
+    sheerka.create_new_concept(get_context(sheerka), Concept("foo", body="foo1"))
+    sheerka.create_new_concept(get_context(sheerka), Concept("foo", body="foo2"))
+
+    concepts = sheerka.new("foo")
+    assert len(concepts) == 2
+
+    foo1 = sheerka.new(("foo", "1001"))
+    assert foo1.body == "foo1"
+
+    foo2 = sheerka.new(("foo", "1002"))
+    assert foo2.body == "foo2"
+
+
 def test_instances_are_different_when_asking_for_new():
     sheerka = get_sheerka()
     concept = get_default_concept()
@@ -357,6 +372,38 @@ def test_i_cannot_instantiate_an_unknown_concept():
     assert new.body == "fake_concept"
 
 
+def test_i_cannot_instantiate_with_invalid_id():
+    sheerka = get_sheerka()
+    sheerka.create_new_concept(get_context(sheerka), Concept("foo", body="foo1"))
+    sheerka.create_new_concept(get_context(sheerka), Concept("foo", body="foo2"))
+
+    new = sheerka.new(("foo", "invalid_id"))
+
+    assert sheerka.isinstance(new, BuiltinConcepts.UNKNOWN_CONCEPT)
+    assert new.body == "foo"
+
+
+def test_i_cannot_instantiate_with_invalid_key():
+    sheerka = get_sheerka()
+    sheerka.create_new_concept(get_context(sheerka), Concept("foo", body="foo1"))
+    sheerka.create_new_concept(get_context(sheerka), Concept("foo", body="foo2"))
+
+    new = sheerka.new(("invalid_key", "1001"))
+
+    assert sheerka.isinstance(new, BuiltinConcepts.UNKNOWN_CONCEPT)
+    assert new.body == "invalid_key"
+
+
+def test_concept_id_is_irrelevant_when_only_one_concept():
+    sheerka = get_sheerka()
+    sheerka.create_new_concept(get_context(sheerka), Concept("foo", body="foo1"))
+
+    new = sheerka.new(("foo", "invalid_id"))
+
+    assert sheerka.isinstance(new, "foo")
+    assert new.body == "foo1"
+
+
 def test_i_cannot_instantiate_when_properties_are_not_recognized():
     sheerka = get_sheerka()
     concept = get_default_concept()