test: accept foreign swap failures for invalid tokens

tests/integration/test_example.py

@@ -136,13 +136,13 @@ async def test_error_handling(
         "/v1/wallet/topup", params={"cashu_token": invalid_token}
     )
 
-    # Should get 400 for invalid token
-    # But the endpoint might return 200 with 0 msats for some invalid tokens
+    # Locally malformed tokens return 400. A decodable token naming an
+    # untrusted mint reaches the automatic swap path and can fail safely with
+    # the documented 422 foreign-swap error instead.
     if response.status_code == 200:
-        # Check if it returned 0 msats
         assert response.json()["msats"] == 0
     else:
-        assert response.status_code == 400
+        assert response.status_code in (400, 422)
         assert "detail" in response.json()
 
     # Test unauthorized access

tests/integration/test_wallet_topup.py

@@ -141,15 +141,19 @@ async def test_topup_with_invalid_token(
             "/v1/wallet/topup", params={"cashu_token": invalid_token}
         )
 
-        # Should fail with 400
-        assert response.status_code == 400, (
-            f"Token {invalid_token[:20]}... should be invalid"
+        # Locally malformed tokens return 400. A decodable token naming an
+        # untrusted mint reaches the automatic swap path and can fail safely
+        # with the documented 422 foreign-swap error instead.
+        assert response.status_code in (400, 422), (
+            f"Token {invalid_token[:20]}... should fail without being credited"
         )
 
         # Validate error response
         validator = ResponseValidator()
         error_validation = validator.validate_error_response(
-            response, expected_status=400, expected_error_key="detail"
+            response,
+            expected_status=response.status_code,
+            expected_error_key="detail",
         )
         assert error_validation["valid"]