fix: validate explicit algorithm order

src/pruna/config/pre_smash_routines.py

@@ -214,7 +214,7 @@ def check_directional_compatibility_violations(graph: nx.DiGraph, algorithm_orde
         for j, alg_after in enumerate(algorithm_order):
             # alg_before comes before alg_after in the provided order
             # Check if there's an edge from alg_after to alg_before in the graph
-            if i < j and not graph.has_edge(alg_before, alg_after):
+            if i < j and graph.has_edge(alg_after, alg_before):
                 violations.append((alg_before, alg_after))
     return violations
 

tests/config/test_pre_smash_routines.py

@@ -27,6 +27,7 @@
     check_argument_compatibility,
     execute_algorithm_pre_smash_hooks,
     check_algorithm_cross_compatibility,
+    check_directional_compatibility_violations,
     determine_algorithm_order,
     construct_algorithm_directed_graph,
 )
@@ -350,6 +351,17 @@ def test_cross_compatibility_disjointly_compatible_algorithms_incompatible_targe
 class TestDetermineAlgorithmOrder:
     """Test suite for determine_algorithm_order function."""
 
+    def test_directional_compatibility_allows_independent_algorithms(self):
+        """Only a reversed dependency should invalidate an explicit order."""
+        graph = nx.DiGraph()
+        graph.add_nodes_from(["algorithm1", "algorithm2", "algorithm3"])
+        graph.add_edge("algorithm1", "algorithm2")
+
+        assert check_directional_compatibility_violations(graph, ["algorithm1", "algorithm2", "algorithm3"]) == []
+        assert check_directional_compatibility_violations(graph, ["algorithm3", "algorithm2", "algorithm1"]) == [
+            ("algorithm2", "algorithm1")
+        ]
+
     def test_determine_algorithm_order_success(self):
         """Test successful algorithm order determination. Should return topologically sorted algorithm order."""
         model = None