1 files changed, 44 insertions, 0 deletions
diff --git a/vespalib/src/tests/coro/lazy/lazy_test.cpp b/vespalib/src/tests/coro/lazy/lazy_test.cpp
new file mode 100644
index 00000000000..a715e473aaf
--- /dev/null
+++ b/vespalib/src/tests/coro/lazy/lazy_test.cpp
@@ -0,0 +1,44 @@
+// Copyright Yahoo. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+
+#include <vespa/vespalib/coro/lazy.h>
+#include <vespa/vespalib/coro/sync_wait.h>
+#include <vespa/vespalib/gtest/gtest.h>
+
+using vespalib::coro::Lazy;
+using vespalib::coro::sync_wait;
+
+Lazy<int> make_lazy(int value) {
+    co_return value;
+}
+
+Lazy<int> async_add_values(int a, int b) {
+    auto lazy_a = make_lazy(a);
+    auto lazy_b = make_lazy(b);
+    co_return (co_await lazy_a + co_await lazy_b);
+}
+
+Lazy<int> async_sum(Lazy<int> a, Lazy<int> b) {
+    co_return (co_await a + co_await b);
+}
+
+TEST(LazyTest, simple_lazy_value) {
+    auto lazy = make_lazy(42);
+    auto result = sync_wait(lazy);
+    EXPECT_EQ(result, 42);
+}
+
+TEST(LazyTest, async_sum_of_async_values) {
+    auto lazy = async_add_values(10, 20);
+    auto result = sync_wait(lazy);
+    EXPECT_EQ(result, 30);
+}
+
+TEST(LazyTest, async_sum_of_external_async_values) {
+    auto a = make_lazy(100);
+    auto b = make_lazy(200);
+    auto lazy = async_sum(std::move(a), std::move(b));
+    auto result = sync_wait(lazy);
+    EXPECT_EQ(result, 300);
+}
+
+GTEST_MAIN_RUN_ALL_TESTS()