test ambiguous case

tests/pipeline_test.py

@@ -868,11 +868,38 @@ def p1(x: T1, y: T2) -> C[T1, T2]:
     def p2(x: A, y: T2) -> C[A, T2]:
         return C[A, T2]("Medium", "Generic")
 
-    def p3(x: A, y: B) -> C[A, B]:
+    def p3(x: T2, y: B) -> C[T2, B]:
+        return C[T2, B]("Generic", "Medium")
+
+    def p4(x: A, y: B) -> C[A, B]:
         return C[A, B]("Kinda", "Special")
 
-    pl = sl.Pipeline([p1, p2, p3], params={A: 'A', B: 'B'})
+    pl = sl.Pipeline([p1, p2, p3, p4], params={A: 'A', B: 'B'})
 
-    assert pl.compute(C[A, B]) == C("Kinda", "Special")
-    assert pl.compute(C[A, A]) == C("Medium", "Generic")
     assert pl.compute(C[B, A]) == C("Very", "Generic")
+    assert pl.compute(C[A, A]) == C("Medium", "Generic")
+    assert pl.compute(C[B, B]) == C("Generic", "Medium")
+    assert pl.compute(C[A, B]) == C("Kinda", "Special")
+
+
+def test_prioritizes_specialized_provider_raises() -> None:
+    A = NewType('A', str)
+    B = NewType('B', str)
+    T1 = TypeVar('T1')
+    T2 = TypeVar('T2')
+
+    @dataclass
+    class C(Generic[T1, T2]):
+        first: T1
+        second: T2
+
+    def p1(x: A, y: T1) -> C[A, T1]:
+        return C[A, T1]("Special", "Generic")
+
+    def p2(x: T1, y: B) -> C[T1, B]:
+        return C[T1, B]("Generic", "Special")
+
+    pl = sl.Pipeline([p1, p2], params={A: 'A', B: 'B'})
+
+    with pytest.raises(sl.AmbiguousProvider):
+        pl.compute(C[A, B])