C# loader: class support - failing test first (TDD) #123

[G00dS0ul]

Description

First step toward class support in the C# loader (part of #123 — make the C# loader production-ready). This is a Draft / TDD red-first PR: it adds a failing test only, no loader implementation yet, so we can agree on the test shape before I build the reflection layer. CI is expected to fail on the legs that have DotNET.

The new test metacall_csharp_class_test mirrors the non-static class section of metacall_java_test, using the file layout of metacall_csharp_static_class_test. It adds a small class.cs (Counter) that exercises the four things class support needs:

• constructor — new Counter(5)
• instance attribute — count == 5
• instance method — Add(7) == 12
• static method — Counter.Twice(21) == 42

It goes red because cs_loader_impl_discover() currently registers only top-level functions and never builds a klass, so metacall_class("Counter") returns NULL.

Follow-up PRs (kept intentionally small): interfaces (blocked on the core templates/generics work) and inheritance.

Part of #123 — first of several PRs, so I've deliberately avoided a closing keyword.

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality) — red test scaffolding only in this PR
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update
• Documentation update

Checklist:

• I have performed a self-review of my own code.
• I have commented my code, particularly in hard-to-understand areas.
• I have made corresponding changes to the documentation.
• My changes generate no new warnings.
• I have added tests/screenshots (if any) that prove my fix is effective or that my feature works.
• I have tested the tests implicated (if any) by my own code and they pass (make test or ctest -VV -R ). — the new test fails as intended (TDD red); it will pass in the follow-up implementation PR.
• If my change is significant or breaking, I have passed all tests with ./docker-compose.sh test &> output and attached the output.
• I have tested my code with OPTION_BUILD_ADDRESS_SANITIZER or ./docker-compose.sh test-address-sanitizer &> output and OPTION_TEST_MEMORYCHECK.
• I have tested my code with OPTION_BUILD_THREAD_SANITIZER or ./docker-compose.sh test-thread-sanitizer &> output.
• I have tested with Helgrind in case my code works with threading.
• I have run make clang-format in order to format my code and my code follows the style guidelines.

[viferga]

static attribute is also needed

[G00dS0ul]

Added in 0065cd4 Counter now has public static int total and the test exercises metacall_class_static_set

[viferga]

you may need to run make clang-format for formatting the c/c++ code

[viferga]

If you use vscode you can add clang plugins to automatically format it.

[G00dS0ul]

you may need to run make clang-format for formatting the c/c++ code

Done in ffca761 scoped the run to just the two new test sources (clang-format -i on main.cpp and metacall_csharp_class_test.cpp), didn't use make clang-format, to avoid the repo-wide diff