Add unit tests

Signed-off-by: JCW <a1q123456@users.noreply.github.com>

include/xrpl/beast/hash/xxhasher.h

@@ -172,7 +172,14 @@ public:
     explicit
     operator result_type() noexcept
     {
-        return retrieveHash();
+        auto result = retrieveHash();
+        resetBuffers();
+        if (state_)
+        {
+            XXH3_freeState(state_);
+            state_ = nullptr;
+        }
+        return result;
     }
 };
 

src/test/beast/xxhasher_test.cpp

@@ -20,6 +20,8 @@ OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 #include <xrpl/beast/hash/xxhasher.h>
 #include <xrpl/beast/unit_test.h>
 
+#include "../../../include/xrpl/protocol/digest.h"
+
 namespace beast {
 
 class XXHasher_test : public unit_test::suite
@@ -182,6 +184,60 @@ public:
             17285302196561698791ULL);
     }
 
+    void
+    testOperatorResultTypeDoesTheSameAsOtherHashers()
+    {
+        testcase("Operator result type does the same as other hashers");
+        xxhasher hasher1;
+        ripple::sha256_hasher hasher2{};
+
+        std::string object{"Hello xxhash"};
+        hasher1(object.data(), object.size());
+        hasher2(object.data(), object.size());
+        auto xxhashResult1 = static_cast<xxhasher::result_type>(hasher1);
+        auto xxhashResult2 = static_cast<xxhasher::result_type>(hasher1);
+
+        auto sha256Result1 = static_cast<ripple::sha256_hasher::result_type>(hasher2);
+        auto sha256Result2 = static_cast<ripple::sha256_hasher::result_type>(hasher2);
+
+        auto xxhashChanged = xxhashResult1 == xxhashResult2;
+        auto sha256Changed = sha256Result1 == sha256Result2;
+        BEAST_EXPECT(xxhashChanged == sha256Changed);
+    }
+
+    void
+    testHasherStateStillValidAfterReset()
+    {
+        testcase("Hasher state still valid after reset");
+        {
+            xxhasher hasher1;
+
+            std::string object{"Hello xxhash"};
+            hasher1(object.data(), object.size());
+            auto xxhashResult1 = static_cast<xxhasher::result_type>(hasher1);
+            hasher1(object.data(), object.size());
+            auto xxhashResult2 = static_cast<xxhasher::result_type>(hasher1);
+
+            BEAST_EXPECT(xxhashResult1 == xxhashResult2);
+        }
+        {
+            xxhasher hasher1;
+
+            std::string object;
+            for (int i = 0; i < 100; i++)
+            {
+                object += "Hello, xxHash!";
+            }
+
+            hasher1(object.data(), object.size());
+            auto xxhashResult1 = static_cast<xxhasher::result_type>(hasher1);
+            hasher1(object.data(), object.size());
+            auto xxhashResult2 = static_cast<xxhasher::result_type>(hasher1);
+
+            BEAST_EXPECT(xxhashResult1 == xxhashResult2);
+        }
+    }
+
     void
     run() override
     {
@@ -194,6 +250,8 @@ public:
         testBigObjectWithSmallAndBigUpdatesWithSeed();
         testBigObjectWithOneUpdateWithoutSeed();
         testBigObjectWithOneUpdateWithSeed();
+        testOperatorResultTypeDoesTheSameAsOtherHashers();
+        testHasherStateStillValidAfterReset();
     }
 };