catcrafts.net/tests/ShouldParseEurcChains/main.cpp

/*
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Copyright (C) 2026 Catcrafts

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No permission is granted to copy, modify, distribute, or create derivative works.
*/

// The EURC rail's two parsers.
//
// The balance decoder is the line between "the buyer paid" and "the node
// errored", and the chains parser is the line between "watching a chain"
// and "silently not watching it". Both refuse rather than guess.

import std;
import Catcrafts.Shared;
import Catcrafts.Server;

using namespace Catcrafts;

namespace {

int failures = 0;

void Check(bool ok, std::string_view what, std::string_view got = {}) {
    if (ok) return;
    ++failures;
    std::println(std::cerr, "FAIL: {}{}{}", what,
                 got.empty() ? "" : "  got: ", got);
}

} // namespace

int main() {
    using Server::ParseEthCallUint;
    Check(ParseEthCallUint(R"({"jsonrpc":"2.0","id":1,"result":"0x0"})") == 0,
          "eurc: zero balance");
    Check(ParseEthCallUint(
              R"({"jsonrpc":"2.0","id":1,"result":"0x0000000000000000000000000000000000000000000000000000000022001230"})")
              == 570430000,
          "eurc: €570.43 as 6-decimal base units, full 32-byte word");
    Check(ParseEthCallUint(R"({"result":"0xFF"})") == 255,
          "eurc: uppercase hex accepted");
    // 2^63 does not fit; the decoder must saturate, never wrap to negative.
    Check(ParseEthCallUint(R"({"result":"0x8000000000000000"})")
              == std::numeric_limits<std::int64_t>::max(),
          "eurc: overflow saturates");
    Check(!ParseEthCallUint(
              R"({"jsonrpc":"2.0","id":1,"error":{"code":-32000,"message":"x"}})")
               .has_value(),
          "eurc: an RPC error is not a zero balance");
    Check(!ParseEthCallUint(R"({"result":"21ff361c"})").has_value(),
          "eurc: missing 0x rejected");
    Check(!ParseEthCallUint(R"({"result":"0x"})").has_value(),
          "eurc: empty word rejected");
    Check(!ParseEthCallUint(R"({"result":42})").has_value(),
          "eurc: numeric result rejected — the wire type is a hex string");
    Check(!ParseEthCallUint("garbage").has_value(), "eurc: malformed payload");

    const auto chains = Server::ParseEurcChains(R"({"chains":[
        {"name":"base","rpc":"https://mainnet.base.org",
         "contract":"0x60a3E35Cc302bFA44Cb288Bc5a4F316Fdb1adb42",
         "chain_id":8453,"note":"lowest fees"},
        {"name":"ethereum","rpc":"https://ethereum-rpc.publicnode.com",
         "contract":"0x1aBaEA1f7C830bD89Acc67eC4af516284b1bC33c","chain_id":1}]})");
    Check(chains.has_value() && chains->size() == 2, "eurc: chains file parses");
    if (chains && chains->size() == 2) {
        Check((*chains)[0].name == "base" && (*chains)[0].chainId == 8453,
              "eurc: file order preserved — first entry is the recommendation");
        Check((*chains)[0].contract == "0x60a3e35cc302bfa44cb288bc5a4f316fdb1adb42",
              "eurc: contract lowercased for comparison");
        Check((*chains)[0].note == "lowest fees", "eurc: note carried");
        Check((*chains)[1].blockTag == "finalized" && (*chains)[1].decimals == 6,
              "eurc: defaults");
    }
    Check(!Server::ParseEurcChains(R"({"chains":[
        {"name":"base","rpc":"https://x.org","contract":"0xdeadbeef"}]})").has_value(),
          "eurc: short contract rejects the whole file");
    Check(!Server::ParseEurcChains(R"({"chains":[
        {"name":"base","rpc":"ftp://x.org",
         "contract":"0x60a3E35Cc302bFA44Cb288Bc5a4F316Fdb1adb42"}]})").has_value(),
          "eurc: non-http rpc rejects the whole file");
    Check(!Server::ParseEurcChains(R"({"chains":[]})").has_value(),
          "eurc: empty chain list rejected");
    Check(!Server::ParseEurcChains("garbage").has_value(),
          "eurc: malformed chains file rejected");

    if (failures != 0) {
        std::println(std::cerr, "{} check(s) failed", failures);
        return 1;
    }
    return 0;
}