Refactor async (#71)

unittests/Async/FileSystem.cpp

@@ -0,0 +1,46 @@
+#include "Test/Test.h"
+#include "Async/Async.h"
+#include "Support/FileSystem.h"
+
+namespace clice::testing {
+
+namespace {
+
+TEST(Async, FileSystemRead) {
+    auto path = fs::createTemporaryFile("prefix", "suffix");
+    EXPECT_TRUE(path.has_value());
+
+    auto result = fs::write(*path, "hello");
+    EXPECT_TRUE(result.has_value());
+
+    auto main = [&] -> async::Task<> {
+        auto content = co_await async::fs::read(*path);
+        EXPECT_TRUE(content.has_value());
+        EXPECT_EQ(*content, "hello");
+    };
+
+    async::run(main());
+}
+
+TEST(Async, FileSystemWrite) {
+    auto path = fs::createTemporaryFile("prefix", "suffix");
+    EXPECT_TRUE(path.has_value());
+
+    auto main = [&] -> async::Task<> {
+        char buffer[] = "hello";
+
+        auto result = co_await async::fs::write(*path, buffer, 5);
+        EXPECT_TRUE(result.has_value());
+    };
+
+    async::run(main());
+
+    auto content = fs::read(*path);
+    EXPECT_TRUE(content.has_value());
+    EXPECT_EQ(*content, "hello");
+}
+
+}  // namespace
+
+}  // namespace clice::testing
+