Add a unit test for invalid memos (#4287)

Builds/CMake/RippledCore.cmake

@@ -909,6 +909,7 @@ if (tests)
     src/test/protocol/InnerObjectFormats_test.cpp
     src/test/protocol/Issue_test.cpp
     src/test/protocol/Hooks_test.cpp
+    src/test/protocol/Memo_test.cpp
     src/test/protocol/PublicKey_test.cpp
     src/test/protocol/Quality_test.cpp
     src/test/protocol/STAccount_test.cpp

src/test/protocol/Memo_test.cpp

@@ -0,0 +1,123 @@
+//------------------------------------------------------------------------------
+/*
+    This file is part of rippled: https://github.com/ripple/rippled
+    Copyright (c) 2022 Ripple Labs Inc.
+
+    Permission to use, copy, modify, and/or distribute this software for any
+    purpose  with  or without fee is hereby granted, provided that the above
+    copyright notice and this permission notice appear in all copies.
+
+    THE  SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+    WITH  REGARD  TO  THIS  SOFTWARE  INCLUDING  ALL  IMPLIED  WARRANTIES  OF
+    MERCHANTABILITY  AND  FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+    ANY  SPECIAL ,  DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+    WHATSOEVER  RESULTING  FROM  LOSS  OF USE, DATA OR PROFITS, WHETHER IN AN
+    ACTION  OF  CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+//==============================================================================
+
+#include <ripple/basics/strHex.h>
+#include <ripple/protocol/jss.h>
+#include <test/jtx.h>
+
+namespace ripple {
+
+class Memo_test : public beast::unit_test::suite
+{
+public:
+    void
+    testMemos()
+    {
+        testcase("Test memos");
+
+        using namespace test::jtx;
+        Account alice{"alice"};
+
+        Env env(*this);
+        env.fund(XRP(10000), alice);
+        env.close();
+
+        // Lambda that returns a valid JTx with a memo that we can hack up.
+        // This is the basis for building tests of invalid states.
+        auto makeJtxWithMemo = [&env, &alice]() {
+            JTx example = noop(alice);
+            memo const exampleMemo{"tic", "tac", "toe"};
+            exampleMemo(env, example);
+            return example;
+        };
+
+        // A valid memo.
+        env(makeJtxWithMemo());
+        env.close();
+
+        {
+            // Make sure that too big a memo is flagged as invalid.
+            JTx memoSize = makeJtxWithMemo();
+            memoSize.jv[sfMemos.jsonName][0u][sfMemo.jsonName]
+                       [sfMemoData.jsonName] = std::string(2020, '0');
+            env(memoSize, ter(temINVALID));
+
+            // This memo is just barely small enough.
+            memoSize.jv[sfMemos.jsonName][0u][sfMemo.jsonName]
+                       [sfMemoData.jsonName] = std::string(2018, '1');
+            env(memoSize);
+        }
+        {
+            // Put a non-Memo in the Memos array.
+            JTx memoNonMemo = noop(alice);
+            auto& jv = memoNonMemo.jv;
+            auto& ma = jv[sfMemos.jsonName];
+            auto& mi = ma[ma.size()];
+            auto& m = mi[sfCreatedNode.jsonName];  // CreatedNode in Memos
+            m[sfMemoData.jsonName] = "3030303030";
+
+            env(memoNonMemo, ter(temINVALID));
+        }
+        {
+            // Put an invalid field in a Memo object.
+            JTx memoExtra = makeJtxWithMemo();
+            memoExtra
+                .jv[sfMemos.jsonName][0u][sfMemo.jsonName][sfFlags.jsonName] =
+                13;
+            env(memoExtra, ter(temINVALID));
+        }
+        {
+            // Put a character that is not allowed in a URL in a MemoType field.
+            JTx memoBadChar = makeJtxWithMemo();
+            memoBadChar.jv[sfMemos.jsonName][0u][sfMemo.jsonName]
+                          [sfMemoType.jsonName] =
+                strHex(std::string_view("ONE<INFINITY"));
+            env(memoBadChar, ter(temINVALID));
+        }
+        {
+            // Put a character that is not allowed in a URL in a MemoData field.
+            // That's okay.
+            JTx memoLegitChar = makeJtxWithMemo();
+            memoLegitChar.jv[sfMemos.jsonName][0u][sfMemo.jsonName]
+                            [sfMemoData.jsonName] =
+                strHex(std::string_view("ONE<INFINITY"));
+            env(memoLegitChar);
+        }
+        {
+            // Put a character that is not allowed in a URL in a MemoFormat.
+            JTx memoBadChar = makeJtxWithMemo();
+            memoBadChar.jv[sfMemos.jsonName][0u][sfMemo.jsonName]
+                          [sfMemoFormat.jsonName] =
+                strHex(std::string_view("NoBraces{}InURL"));
+            env(memoBadChar, ter(temINVALID));
+        }
+    }
+
+    //--------------------------------------------------------------------------
+
+    void
+    run() override
+    {
+        testMemos();
+    }
+};
+
+BEAST_DEFINE_TESTSUITE(Memo, ripple_data, ripple);
+
+}  // namespace ripple