From f9711f6bca81fbf47c116e8e0e923419c7b7e001 Mon Sep 17 00:00:00 2001
From: leftibot <leftibot@users.noreply.github.com>
Date: Sat, 11 Apr 2026 15:01:41 -0600
Subject: [PATCH] Address review: remove issue references from comments, add
 round-trip conversion tests

Requested by @lefticus in PR #663 review.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
---
 .../dispatchkit/proxy_functions.hpp           |  2 +-
 unittests/compiled_tests.cpp                  | 45 ++++++++++++++-----
 2 files changed, 36 insertions(+), 11 deletions(-)

diff --git a/include/chaiscript/dispatchkit/proxy_functions.hpp b/include/chaiscript/dispatchkit/proxy_functions.hpp
index 9830f190..002e473b 100644
--- a/include/chaiscript/dispatchkit/proxy_functions.hpp
+++ b/include/chaiscript/dispatchkit/proxy_functions.hpp
@@ -801,7 +801,7 @@ namespace chaiscript {
 
           // Deprioritize functions whose first parameter (object/receiver) requires
           // type conversion: conversions create temporaries, so mutations on the
-          // converted object are silently lost (issue #405).
+          // converted object are silently lost.
           if (plist.size() > 1 && !func->get_param_types()[1].bare_equal(plist[0].get_type_info())) {
             numdiffs = plist.size();
           }
diff --git a/unittests/compiled_tests.cpp b/unittests/compiled_tests.cpp
index 2bcbb587..5a3f09d1 100644
--- a/unittests/compiled_tests.cpp
+++ b/unittests/compiled_tests.cpp
@@ -1437,28 +1437,37 @@ TEST_CASE("Issue #421 - Switch with type_conversion does not compare destroyed o
   })") == 0);
 }
 
-// Regression test for issue #405: push_back() on script-created vector has
-// no effect when vector_conversion is in effect. The bug occurs because
-// dispatch selects the C++ push_back for the converted type over the built-in
-// one, operating on a temporary copy of the vector.
-TEST_CASE("push_back on script vector with vector_conversion (#405)") {
+// Regression test: push_back() on script-created vector has no effect when
+// vector_conversion is in effect. The bug occurs because dispatch selects
+// the C++ push_back for the converted type over the built-in one, operating
+// on a temporary copy of the vector.
+TEST_CASE("push_back on script vector with vector_conversion") {
   chaiscript::ChaiScript_Basic chai(create_chaiscript_stdlib(), create_chaiscript_parser());
 
-  // Register both vector_type and vector_conversion for std::vector<std::string>,
-  // which is the combination that triggers the bug
   auto m = std::make_shared<chaiscript::Module>();
   chaiscript::bootstrap::standard_library::vector_type<std::vector<std::string>>("VectorString", *m);
   m->add(chaiscript::vector_conversion<std::vector<std::string>>());
   chai.add(m);
 
-  // push_back on an empty script-created vector
+  // Register a C++ function that accepts the converted type, so we can
+  // verify that vector_conversion actually works for passing vectors
+  chai.add(chaiscript::fun([](const std::vector<std::string> &v) -> std::string {
+    std::string result;
+    for (const auto &s : v) {
+      if (!result.empty()) { result += ","; }
+      result += s;
+    }
+    return result;
+  }), "join_strings");
+
+  // push_back on an empty script-created vector must be visible
   CHECK(chai.eval<bool>(
     "auto x = [];"
     "x.push_back(\"Hello\");"
     "x.size() == 1"
   ));
 
-  // push_back on a script-created vector with initial elements
+  // push_back on a vector with initial elements must grow correctly
   CHECK(chai.eval<bool>(
     "auto y = [\"a\", \"b\"];"
     "y.push_back(\"c\");"
@@ -1466,12 +1475,28 @@ TEST_CASE("push_back on script vector with vector_conversion (#405)") {
     "y.size() == 4"
   ));
 
-  // Verify the actual content is preserved
+  // Verify the actual content is preserved after push_back
   CHECK(chai.eval<std::string>(
     "auto z = [];"
     "z.push_back(\"World\");"
     "z[0]"
   ) == "World");
+
+  // Round-trip: build a vector in script, push_back elements, then pass it
+  // to a C++ function via vector_conversion and verify the contents
+  CHECK(chai.eval<std::string>(
+    "auto v = [\"one\", \"two\"];"
+    "v.push_back(\"three\");"
+    "join_strings(v)"
+  ) == "one,two,three");
+
+  // Verify conversion works on a freshly created vector too
+  CHECK(chai.eval<std::string>(
+    "auto w = [];"
+    "w.push_back(\"hello\");"
+    "w.push_back(\"world\");"
+    "join_strings(w)"
+  ) == "hello,world");
 }
 
 // Regression test for issue #607: AST_Node_Trace must be a complete type