add unit test for default python configuration

Author: Daniel Jacobs

tests/test_embed/test_interpreter.cpp

@@ -184,6 +184,8 @@ TEST_CASE("Custom PyConfig") {
     py::initialize_interpreter();
 }
 
+#    include <iostream>
+
 TEST_CASE("Custom PyConfig with argv") {
     py::finalize_interpreter();
     {
@@ -197,6 +199,22 @@ TEST_CASE("Custom PyConfig with argv") {
         const auto &cpp_widget = py_widget.cast<const Widget &>();
         REQUIRE(cpp_widget.argv0() == "a.out");
     }
+
+    {
+        PyConfig config;
+        PyConfig_InitPythonConfig(&config);
+
+        // Parse arguments the way python normally does, and strip the first argument (which is
+        // expected to be "python")
+        char *argv[] = {strdup("python"), strdup("a.out")};
+        py::scoped_interpreter argv_scope(&config, 2, argv);
+        std::free(argv[0]);
+        std::free(argv[1]);
+        auto module = py::module::import("test_interpreter");
+        auto py_widget = module.attr("DerivedWidget")("The question");
+        const auto &cpp_widget = py_widget.cast<const Widget &>();
+        REQUIRE(cpp_widget.argv0() == "a.out");
+    }
     py::initialize_interpreter();
 }
 #endif