test: refactor: Accept any RandomNumberGenerator in RandMoney

Accepting any Rng in RandMoney makes tests more flexible to use a
different Rng. Also, passing in the Rng clarifies the call sites, so
that they all use g_rand_ctx explicitly and consistently.

Author: MarcoFalke

src/test/coins_tests.cpp

@@ -182,7 +182,7 @@ void SimulationTest(CCoinsView* base, bool fake_best_block)
 
             if (InsecureRandRange(5) == 0 || coin.IsSpent()) {
                 Coin newcoin;
-                newcoin.out.nValue = InsecureRandMoneyAmount();
+                newcoin.out.nValue = RandMoney(m_rng);
                 newcoin.nHeight = 1;
 
                 // Infrequently test adding unspendable coins.

src/test/sighash_tests.cpp

@@ -110,7 +110,7 @@ void RandomTransaction(CMutableTransaction& tx, bool fSingle)
     for (int out = 0; out < outs; out++) {
         tx.vout.emplace_back();
         CTxOut &txout = tx.vout.back();
-        txout.nValue = InsecureRandMoneyAmount();
+        txout.nValue = RandMoney(m_rng);
         RandomScript(txout.scriptPubKey);
     }
 }

src/test/util/coins.cpp

@@ -18,7 +18,7 @@ COutPoint AddTestCoin(FastRandomContext& rng, CCoinsViewCache& coins_view)
     Coin new_coin;
     COutPoint outpoint{Txid::FromUint256(rng.rand256()), /*nIn=*/0};
     new_coin.nHeight = 1;
-    new_coin.out.nValue = InsecureRandMoneyAmount();
+    new_coin.out.nValue = RandMoney(rng);
     new_coin.out.scriptPubKey.assign(uint32_t{56}, 1);
     coins_view.AddCoin(outpoint, std::move(new_coin), /*possible_overwrite=*/false);
 

src/test/util/random.h

@@ -1,4 +1,4 @@
-// Copyright (c) 2023 The Bitcoin Core developers
+// Copyright (c) 2023-present The Bitcoin Core developers
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
@@ -52,9 +52,10 @@ static inline bool InsecureRandBool()
     return g_insecure_rand_ctx.randbool();
 }
 
-static inline CAmount InsecureRandMoneyAmount()
+template <RandomNumberGenerator Rng>
+inline CAmount RandMoney(Rng&& rng)
 {
-    return static_cast<CAmount>(InsecureRandRange(MAX_MONEY + 1));
+    return CAmount{rng.randrange(MAX_MONEY + 1)};
 }
 
 #endif // BITCOIN_TEST_UTIL_RANDOM_H