arm: async echo app

arm/ring_buffer_test.cc

@@ -0,0 +1,42 @@
+#include "ring_buffer.h"
+
+#include <gmock/gmock.h>
+#include <gtest/gtest.h>
+
+#include <array>
+
+using namespace ::testing;
+
+TEST(RingBuffer, BasicStoreLoad) {
+    std::array<char, 20> arr;
+    RingBuffer rb{.buffer = std::as_writable_bytes(std::span{arr})};
+
+    std::array<char, 10> a0 = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9};
+    std::array<char, 10> a1 = {};
+
+    ASSERT_TRUE(rb.Store(std::as_bytes(std::span{a0})));
+    ASSERT_TRUE(rb.Load(std::as_writable_bytes(std::span{a1})));
+
+    EXPECT_THAT(a1, ElementsAre(0, 1, 2, 3, 4, 5, 6, 7, 8, 9));
+}
+
+TEST(RingBuffer, StoreOverflow) {
+    std::array<char, 10> arr;
+    RingBuffer rb{.buffer = std::as_writable_bytes(std::span{arr})};
+
+    std::array<char, 8> a0 = {0, 1, 2, 3, 4, 5, 6, 7};
+    std::array<char, 8> a1 = {};
+
+    ASSERT_TRUE(rb.Store(std::as_bytes(std::span{a0})));
+    ASSERT_FALSE(rb.Store(std::as_bytes(std::span{a0})));
+
+    EXPECT_EQ(rb.AvailableData(), 8);
+
+    ASSERT_TRUE(rb.Pop(7));
+    EXPECT_EQ(rb.AvailableData(), 1);
+
+    EXPECT_TRUE(rb.Store(std::as_bytes(std::span{a0})));
+    ASSERT_TRUE(rb.Load(std::as_writable_bytes(std::span{a1})));
+    // one byte leftover from first run, then 7 more
+    EXPECT_THAT(a1, ElementsAre(7, 0, 1, 2, 3, 4, 5, 6));
+}