Add process unit tests

tests/UnitTests/subprocess1.cpp

@@ -0,0 +1,39 @@
+#include <Nazara/Core/File.hpp>
+#include <Nazara/Core/Format.hpp>
+#include <Nazara/Core/Process.hpp>
+#include <NazaraUtils/PathUtils.hpp>
+#include <chrono>
+#include <string>
+#include <thread>
+
+int main(int argc, char* argv[])
+{
+	{
+		Nz::File file(Nz::Utf8Path("step1_success.txt"), Nz::OpenMode::Write);
+		file.Write("1");
+	}
+
+	for (int i = 1; i < argc; ++i)
+	{
+		Nz::File file(Nz::Utf8Path(Nz::Format("step2_param{}.txt", i)), Nz::OpenMode::Write);
+		file.Write(argv[i]);
+	}
+
+	std::vector<std::string> parameters;
+	parameters.push_back(std::to_string(Nz::Process::GetCurrentPid()));
+
+	Nz::Result result = Nz::Process::SpawnDetached("../UnitTests_sub2", parameters);
+	if (result)
+	{
+		Nz::File file(Nz::Utf8Path("step3_pid.txt"), Nz::OpenMode::Write);
+		file.Write(std::to_string(result.GetValue()));
+	}
+	else
+	{
+		Nz::File file(Nz::Utf8Path("step3_failure.txt"), Nz::OpenMode::Write);
+		file.Write(result.GetError());
+	}
+
+	// Wait for our child process to start and check for our existence
+	std::this_thread::sleep_for(std::chrono::milliseconds(200));
+}