Fix loading difficulty for BlockInfo

Author: rodiazet

test/statetest/statetest_loader.cpp

@@ -75,7 +75,12 @@ address from_json<address>(const json::json& j)
 template <>
 hash256 from_json<hash256>(const json::json& j)
 {
-    return evmc::from_hex<hash256>(j.get<std::string>()).value();
+    // Special case to handle "0". Required by exec-spec-tests.
+    // TODO: Get rid of it.
+    if (j.is_string() && (j == "0" || j == "0x0"))
+        return 0x00_bytes32;
+    else
+        return evmc::from_hex<hash256>(j.get<std::string>()).value();
 }
 
 template <>
@@ -148,18 +153,11 @@ state::BlockInfo from_json<state::BlockInfo>(const json::json& j)
     const auto current_difficulty_it = j.find("currentDifficulty");
     const auto parent_difficulty_it = j.find("parentDifficulty");
     if (prev_randao_it != j.end())
-    {
-        // Special case to handle "0". Required by exec-spec-tests.
-        // TODO: Get rid of it.
-        if (prev_randao_it->is_string() && prev_randao_it->get<std::string>() == "0")
-            difficulty = 0x0000000000000000000000000000000000000000000000000000000000000000_bytes32;
-        else
-            difficulty = from_json<evmc::bytes32>(*prev_randao_it);
-    }
+        difficulty = from_json<bytes32>(*prev_randao_it);
     else if (current_difficulty_it != j.end())
-        difficulty = from_json<evmc::bytes32>(*current_difficulty_it);
+        difficulty = from_json<bytes32>(*current_difficulty_it);
     else if (parent_difficulty_it != j.end())
-        difficulty = from_json<evmc::bytes32>(*parent_difficulty_it);
+        difficulty = from_json<bytes32>(*parent_difficulty_it);
 
     uint64_t base_fee = 0;
     if (j.contains("currentBaseFee"))

test/unittests/statetest_loader_block_info_test.cpp

@@ -91,6 +91,64 @@ TEST(statetest_loader, block_info_dec)
     EXPECT_EQ(bi.number, 1);
 }
 
+TEST(statetest_loader, block_info_0_current_difficulty)
+{
+    constexpr std::string_view input = R"({
+        "currentCoinbase": "0x2adc25665018aa1fe0e6bc666dac8fc2697ff9ba",
+        "currentGasLimit": "100000000000000000",
+        "currentNumber": "1",
+        "currentTimestamp": "1000",
+        "currentDifficulty": "0",
+        "parentBaseFee": "7",
+        "parentGasUsed": "0",
+        "parentGasLimit": "100000000000000000",
+        "parentTimstamp": "0",
+        "blockHashes": {
+            "0": "0xc305d826e3784046a7e9d31128ef98d3e96133fe454c16ef630574d967dfdb1a"
+        },
+        "ommers": [],
+        "withdrawals": [],
+        "parentUncleHash": "0x1dcc4de8dec75d7aab85b567b6ccd41ad312451b948a7413f0a142fd40d49347"
+    })";
+
+    const auto bi = test::from_json<state::BlockInfo>(json::json::parse(input));
+    EXPECT_EQ(bi.coinbase, 0x2adc25665018aa1fe0e6bc666dac8fc2697ff9ba_address);
+    EXPECT_EQ(bi.prev_randao, 0x00_bytes32);
+    EXPECT_EQ(bi.gas_limit, 100000000000000000);
+    EXPECT_EQ(bi.base_fee, 7);
+    EXPECT_EQ(bi.timestamp, 1000);
+    EXPECT_EQ(bi.number, 1);
+}
+
+TEST(statetest_loader, block_info_0_parent_difficulty)
+{
+    constexpr std::string_view input = R"({
+        "currentCoinbase": "0x2adc25665018aa1fe0e6bc666dac8fc2697ff9ba",
+        "currentGasLimit": "100000000000000000",
+        "currentNumber": "1",
+        "currentTimestamp": "1000",
+        "parentDifficulty": "0x0",
+        "parentBaseFee": "7",
+        "parentGasUsed": "0",
+        "parentGasLimit": "100000000000000000",
+        "parentTimstamp": "0",
+        "blockHashes": {
+            "0": "0xc305d826e3784046a7e9d31128ef98d3e96133fe454c16ef630574d967dfdb1a"
+        },
+        "ommers": [],
+        "withdrawals": [],
+        "parentUncleHash": "0x1dcc4de8dec75d7aab85b567b6ccd41ad312451b948a7413f0a142fd40d49347"
+    })";
+
+    const auto bi = test::from_json<state::BlockInfo>(json::json::parse(input));
+    EXPECT_EQ(bi.coinbase, 0x2adc25665018aa1fe0e6bc666dac8fc2697ff9ba_address);
+    EXPECT_EQ(bi.prev_randao, 0x00_bytes32);
+    EXPECT_EQ(bi.gas_limit, 100000000000000000);
+    EXPECT_EQ(bi.base_fee, 7);
+    EXPECT_EQ(bi.timestamp, 1000);
+    EXPECT_EQ(bi.number, 1);
+}
+
 TEST(statetest_loader, block_info_0_random)
 {
     constexpr std::string_view input = R"({