Compilation failure in test_graph_node.h with disable_exceptions=false

[ze2j]

Tested versions

Reproducible in 4.3 RC1 [607b230]

System information

Godot v4.3.rc (607b230) - Ubuntu 22.04.4 LTS 22.04 - X11 - Vulkan (Forward+) - dedicated NVIDIA GeForce GTX 1070 (nvidia; 535.183.01) - Intel(R) Core(TM) i7-7700K CPU @ 4.20GHz (8 Threads)

Issue description

test_graph_node.h compilation fails when disable_exception=false is used:

In file included from ./tests/test_macros.h:43,
                 from ./tests/core/config/test_project_settings.h:37,
                 from tests/test_main.cpp:40:
./tests/scene/test_graph_node.h: In lambda function:
./thirdparty/doctest/doctest.h:2355:30: error: expected primary-expression before ';' token
 2355 |         mb_name * __VA_ARGS__;                                                                     \
      |                              ^
./thirdparty/doctest/doctest.h:2345:5: note: in expansion of macro 'DOCTEST_INFO_IMPL'
 2345 |     DOCTEST_INFO_IMPL(DOCTEST_ANONYMOUS(DOCTEST_CAPTURE_),                                         \
      |     ^~~~~~~~~~~~~~~~~
./thirdparty/doctest/doctest.h:2559:77: note: in expansion of macro 'DOCTEST_INFO'
 2559 | #define DOCTEST_CHECK_NOTHROW_MESSAGE(expr, ...) DOCTEST_FUNC_SCOPE_BEGIN { DOCTEST_INFO(__VA_ARGS__); DOCTEST_CHECK_NOTHROW(expr); } DOCTEST_FUNC_SCOPE_END
      |                                                                             ^~~~~~~~~~~~
./thirdparty/doctest/doctest.h:2997:42: note: in expansion of macro 'DOCTEST_CHECK_NOTHROW_MESSAGE'
 2997 | #define CHECK_NOTHROW_MESSAGE(expr, ...) DOCTEST_CHECK_NOTHROW_MESSAGE(expr, __VA_ARGS__)
      |                                          ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
./tests/scene/test_graph_node.h:51: note: in expansion of macro 'CHECK_NOTHROW_MESSAGE'
   51 |                 CHECK_NOTHROW_MESSAGE(test_node->remove_child(test_child));
      | 

When exceptions are enabled, a compilation error occurs because CHECK_NOTHROW_MESSAGE expects an error message argument. In this case the fix would be to provide one, or use CHECK_NOTHROW instead and memdelete the child to fix the memory leak.

When exceptions are disabled the check macro (and its argument) expand to nothing: remove_child is not called and there is no memory leak because the child is still parented.

IMO the correct fix is to drop the CHECK_NOTHROW macro, always call remove_child and make sure the child is deleted. We could add a CHECK on the child count instead.

Note: CHECK_NOTHROW macro and its variant are never used in the codebase except there.

Related: Fix error message when removing only child from GraphNode #90229

Steps to reproduce

Try to build Godot's tests with disable_exceptions=false

In my case:
scons platform=linuxbsd target=editor dev_build=yes tests=true disable_exceptions=false -j9

Minimal reproduction project (MRP)

NA