Add unit tests for Fletcher-16.

tests/fletcher16.cpp

@@ -0,0 +1,54 @@
+//
+// Created by claunia on 5/10/21.
+//
+
+#include <cstdint>
+
+#include "../library.h"
+#include "../fletcher16.h"
+#include "gtest/gtest.h"
+
+#define EXPECTED_FLETCHER16 0x3357
+
+static const uint8_t* buffer;
+
+class fletcher16Fixture : public ::testing::Test
+{
+  public:
+    fletcher16Fixture()
+    {
+        // initialization;
+        // can also be done in SetUp()
+    }
+
+  protected:
+    void SetUp()
+    {
+        FILE* file = fopen("/home/claunia/random", "rb");
+        buffer     = (const uint8_t*)malloc(1048576);
+        fread((void*)buffer, 1, 1048576, file);
+        fclose(file);
+    }
+
+    void TearDown() { free((void*)buffer); }
+
+    ~fletcher16Fixture()
+    {
+        // resources cleanup, no exceptions allowed
+    }
+
+    // shared user data
+};
+
+TEST_F(fletcher16Fixture, fletcher16_auto)
+{
+    fletcher16_ctx* ctx = fletcher16_init();
+    uint16_t        fletcher;
+
+    EXPECT_NE(ctx, nullptr);
+
+    fletcher16_update(ctx, buffer, 1048576);
+    fletcher16_final(ctx, &fletcher);
+
+    EXPECT_EQ(fletcher, EXPECTED_FLETCHER16);
+}