test: remove old recursive FindChallenges_recursive implementation

The performance of the test is the same as before, with the recursive method.

Author: l0rinc

src/test/miniscript_tests.cpp

@@ -296,33 +296,6 @@ using NodeRef = miniscript::NodeRef<CPubKey>;
 using miniscript::operator""_mst;
 using Node = miniscript::Node<CPubKey>;
 
-/** Compute all challenges (pubkeys, hashes, timelocks) that occur in a given Miniscript. */
-// NOLINTNEXTLINE(misc-no-recursion)
-std::set<Challenge> FindChallenges_recursive(const NodeRef& ref) {
-    std::set<Challenge> chal;
-    for (const auto& key : ref->keys) {
-        chal.emplace(ChallengeType::PK, ChallengeNumber(key));
-    }
-    if (ref->fragment == miniscript::Fragment::OLDER) {
-        chal.emplace(ChallengeType::OLDER, ref->k);
-    } else if (ref->fragment == miniscript::Fragment::AFTER) {
-        chal.emplace(ChallengeType::AFTER, ref->k);
-    } else if (ref->fragment == miniscript::Fragment::SHA256) {
-        chal.emplace(ChallengeType::SHA256, ChallengeNumber(ref->data));
-    } else if (ref->fragment == miniscript::Fragment::RIPEMD160) {
-        chal.emplace(ChallengeType::RIPEMD160, ChallengeNumber(ref->data));
-    } else if (ref->fragment == miniscript::Fragment::HASH256) {
-        chal.emplace(ChallengeType::HASH256, ChallengeNumber(ref->data));
-    } else if (ref->fragment == miniscript::Fragment::HASH160) {
-        chal.emplace(ChallengeType::HASH160, ChallengeNumber(ref->data));
-    }
-    for (const auto& sub : ref->subs) {
-        auto sub_chal = FindChallenges_recursive(sub);
-        chal.insert(sub_chal.begin(), sub_chal.end());
-    }
-    return chal;
-}
-
 /** Compute all challenges (pubkeys, hashes, timelocks) that occur in a given Miniscript. */
 std::set<Challenge> FindChallenges(const NodeRef& root)
 {
@@ -379,9 +352,7 @@ struct MiniScriptTest : BasicTestingSetup {
 /** Run random satisfaction tests. */
 void TestSatisfy(const KeyConverter& converter, const std::string& testcase, const NodeRef& node) {
     auto script = node->ToScript(converter);
-    const auto challenges_recursive{FindChallenges_recursive(node)};
     const auto challenges{FindChallenges(node)}; // Find all challenges in the generated miniscript.
-    BOOST_CHECK(challenges_recursive == challenges);
     std::vector<Challenge> challist(challenges.begin(), challenges.end());
     for (int iter = 0; iter < 3; ++iter) {
         std::shuffle(challist.begin(), challist.end(), m_rng);