Add some FFI tests

.github/workflows/rust.yml

@@ -85,6 +85,29 @@ jobs:
         run: cargo build --quiet --all-features
       - name: Test --all-features
         run: cargo test --all-features
+  ffi:
+    name: Test FFI (${{ matrix.rust.name }}, ${{ matrix.os }})
+    strategy:
+      matrix:
+        rust:
+          - { version: stable, name: stable }
+        os: [ubuntu-latest] # Todo: potentially add more if we add cpp tests
+    runs-on: ${{ matrix.os }}
+    steps:
+      - uses: actions/checkout@v4
+      - uses: dtolnay/rust-toolchain@master
+        with:
+          toolchain: ${{ matrix.rust.version }}
+      - uses: Swatinem/rust-cache@v2
+        with:
+          key: ffi
+      - name: Cargo build
+        run: cargo build -p temporal_capi
+      - name: Regen
+        run: cargo run -p diplomat-gen
+      # Todo: eventually we should check in bindings and test them
+      - name: Makefile tests
+        run: cd temporal_capi/cpp_tests && make
 
   docs:
     name: Documentation

temporal_capi/.gitignore

@@ -0,0 +1,3 @@
+# To be checked in later once it stabilizes a bit
+bindings/
+*.out

temporal_capi/cpp_tests/Makefile

@@ -0,0 +1,25 @@
+.DEFAULT_GOAL := test
+.PHONY: build test
+FORCE:
+
+HEADERS := ../bindings/cpp/
+ALL_HEADERS := $(wildcard ${HEADERS}/**/*.hpp)
+
+CXX?=g++
+
+TEST_FILES := $(wildcard *.cpp)
+OUT_FILES = $(patsubst %.cpp,%.out,$(TEST_FILES))
+
+$(ALL_HEADERS):
+
+../../target/debug/libtemporal_capi.a: FORCE
+	cargo rustc -p temporal_capi --crate-type staticlib
+
+%.out: %.cpp ../../target/debug/libtemporal_capi.a $(ALL_HEADERS)
+	$(CXX) -std=c++17 -L ../../target/debug/ -I ${HEADERS} $< -ltemporal_capi -lm -o $@
+	./$@
+
+test: $(OUT_FILES)
+
+clean:
+	rm $(OUT_FILES)

temporal_capi/cpp_tests/simple.cpp

@@ -0,0 +1,17 @@
+#include <temporal_rs/Calendar.hpp>
+#include <temporal_rs/PlainDate.hpp>
+
+#include <iostream>
+
+using namespace temporal_rs;
+
+int main() {
+    auto c = Calendar::create(AnyCalendarKind::Gregorian);
+
+    auto date = PlainDate::create_with_overflow(2025, 1, 33, *c, ArithmeticOverflow::Constrain).ok().value();
+
+    auto formatted = date->to_ixdtf_string(DisplayCalendar::Always);
+
+    std::cout<<formatted<<std::endl;
+
+}