[pyrefly] Keep positional inlay hints after keyword insertion

pyrefly/lib/lsp/wasm/inlay_hints.rs

@@ -429,10 +429,18 @@ impl<'a> Transaction<'a> {
                                 .keywords
                                 .iter()
                                 .any(|kw| kw.value.range() == arg.range());
+                            let keyword_args_before = call
+                                .arguments
+                                .keywords
+                                .iter()
+                                .filter(|kw| kw.range().start() < arg.range().start())
+                                .count();
 
                             if !is_keyword_arg
-                                && let Some(param_match) =
-                                    Self::param_name_for_positional_argument(&params, arg_idx)
+                                && let Some(param_match) = Self::param_name_for_positional_argument(
+                                    &params,
+                                    arg_idx + keyword_args_before,
+                                )
                                 && !param_match.is_vararg_repeat
                                 && param_match.name.as_str() != "self"
                                 && param_match.name.as_str() != "cls"

pyrefly/lib/test/lsp/inlay_hint.rs

@@ -417,6 +417,38 @@ obj.method(5, "world")
     );
 }
 
+#[test]
+fn test_parameter_name_hints_after_keyword_insertion() {
+    let code = r#"
+def example(a: str, b: str) -> None:
+    pass
+
+# This is the transient source after inserting the first positional hint.
+example(a="a", "b")
+"#;
+    let files = [("main", code)];
+    let (handles, state) = mk_multi_file_state(&files, Require::Exports, false);
+    let hints = state
+        .transaction()
+        .inlay_hints(
+            handles.get("main").unwrap(),
+            InlayHintConfig {
+                call_argument_names: AllOffPartial::All,
+                variable_types: false,
+                ..Default::default()
+            },
+        )
+        .unwrap();
+    let labels: Vec<String> = hints
+        .into_iter()
+        .filter_map(|hint| {
+            let label: String = hint.label_parts.into_iter().map(|(text, _)| text).collect();
+            label.ends_with("= ").then_some(label)
+        })
+        .collect();
+    assert_eq!(labels, vec!["b= "]);
+}
+
 #[test]
 fn test_parameter_name_hints_with_variable_types() {
     let code = r#"