From d07c91cba968e75cfd679ac0704327d388829f2e Mon Sep 17 00:00:00 2001
From: Jarvis-J-Jacob <287212888+Jarvis-J-Jacob@users.noreply.github.com>
Date: Mon, 5 Oct 2026 13:51:53 +0530
Subject: [PATCH] test(csharp): assert bare this?.M() null-conditional call
 resolves

#3976 made recv?.M() resolve through the receiver-typed path but only
tested field receivers. Add a test that `this?.Save()` inside a class
resolves to the enclosing class's Save() like `this.Save()`, and not to
an unrelated class's Save().

Fixes #4077

(cherry picked from commit 6ce83480263f8041b17e027ac85789dc8f382a45)
---
 tests/test_csharp_member_calls.py | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/tests/test_csharp_member_calls.py b/tests/test_csharp_member_calls.py
index 96debbd1f..ba0090d53 100644
--- a/tests/test_csharp_member_calls.py
+++ b/tests/test_csharp_member_calls.py
@@ -320,6 +320,24 @@ def test_null_conditional_this_field_receiver_resolves(tmp_path):
     assert (commit, cache_save) not in calls
 
 
+def test_null_conditional_bare_this_receiver_resolves(tmp_path):
+    """`this?.Save()` resolves like `this.Save()` (#4077)."""
+    calls, r = _calls(tmp_path, {
+        "S.cs": (
+            "public class Other { public bool Save() => false; }\n"
+            "public class Repo {\n"
+            "    public bool Save() => true;\n"
+            "    public bool? Commit() { return this?.Save(); }\n"
+            "}\n"
+        )
+    })
+    commit = _find(r, ".Commit()", "commit")
+    repo_save = _find(r, ".Save()", "repo")
+    other_save = _find(r, ".Save()", "other")
+    assert (commit, repo_save) in calls, "this?.Save() must resolve like this.Save()"
+    assert (commit, other_save) not in calls
+
+
 def test_null_conditional_cross_file_receiver_resolves(tmp_path):
     calls, r = _calls(tmp_path, {
         "Server.cs": (