Allow default option to be overriden if there is any conversion point that injects this default option

src/breakshaft/graph_walker.py

@@ -69,6 +69,16 @@ class GraphWalker:
                     variant_subgraphs.add(subg)
 
                 if not dead_end:
+
+                    for opt, _ in point.opt_args:
+                        subg = cls.generate_callgraph_singletype(injectors,
+                                                                 from_types,
+                                                                 opt,
+                                                                 visited_path=visited_path.copy(),
+                                                                 visited_types=visited_types.copy())
+                        if subg is not None:
+                            variant_subgraphs.add(subg)
+
                     consumed = frozenset(point.requires) & from_types
                     variant = CallgraphVariant(point, frozenset(variant_subgraphs), consumed)
                     head = head.add_subgraph_variant(variant)

tests/test_default_args.py

@@ -76,3 +76,39 @@ def test_default_inj_args():
     fn3 = repo.get_conversion((int, optC,), consumer, force_commutative=True, force_async=False, allow_async=False)
     dep = fn3(123, '0')
     assert dep == 123
+
+
+def test_default_graph_override():
+
+    repo = ConvRepo()
+
+    @repo.mark_injector()
+    def b_to_a(b: B) -> A:
+        return A(int(b.b))
+
+    @repo.mark_injector()
+    def a_to_b(a: A) -> B:
+        return B(float(a.a))
+
+    @repo.mark_injector()
+    def int_to_a(i: int, opt_dep: optC = '42') -> A:
+        return A(i + int(opt_dep))
+
+    @repo.mark_injector()
+    def inject_opt_dep() -> optC:
+        return '12345'
+
+    def consumer(dep: A) -> int:
+        return dep.a
+
+    fn1 = repo.get_conversion((B,), consumer, force_commutative=True, force_async=False, allow_async=False)
+    dep = fn1(B(42.1))
+    assert dep == 42
+
+    fn2 = repo.get_conversion((int,), consumer, force_commutative=True, force_async=False, allow_async=False)
+    dep = fn2(123)
+    assert dep == 123 + 12345
+
+    fn3 = repo.get_conversion((int, optC,), consumer, force_commutative=True, force_async=False, allow_async=False)
+    dep = fn3(123, '0')
+    assert dep == 123