Bind positional-only arguments correctly in direct and HTTP calls

tests/test_argument_regressions.py

@@ -17,3 +17,18 @@ def test_keyword_only_inputs_are_validated_and_exposed(isolated_context: None) -
     with TestClient(predict.app) as client:
         assert client.post("/predict", json={"value": 8}).json()["output"] == 8
         assert client.post("/predict", json={"value": "wrong"}).status_code == 422
+
+
+def test_positional_only_inputs_keep_their_bindings(isolated_context: None) -> None:
+    @GreatAI.create
+    def predict(first: str, /, second: int = 7) -> str:
+        return first * second
+
+    trace = predict("a", 2)
+    assert trace.output == "aa"
+    assert trace.logged_values["arg:first:value"] == "a"
+    assert trace.logged_values["arg:second:value"] == 2
+    with TestClient(predict.app) as client:
+        response = client.post("/predict", json={"first": "b", "second": 3})
+        assert response.status_code == 200
+        assert response.json()["output"] == "bbb"