Added GnosisSpecProvider and gnosis_loads_properly test

src/Nethermind/Nethermind.Specs.Test/ChainSpecStyle/ChainSpecBasedSpecProviderTests.cs

@@ -232,6 +232,47 @@ public void Chiado_loads_properly()
         provider.GetSpec((1, ChiadoSpecProvider.ShanghaiTimestamp)).MaxInitCodeSize.Should().Be(2 * 24576L);
     }
 
+    [Test]
+    public void Gnosis_loads_properly()
+    {
+        ChainSpecLoader loader = new(new EthereumJsonSerializer());
+        string path = Path.Combine(TestContext.CurrentContext.WorkDirectory, "../../../../Chains/gnosis.json");
+        ChainSpec chainSpec = loader.Load(File.ReadAllText(path));
+
+        ChainSpecBasedSpecProvider provider = new(chainSpec);
+        GnosisSpecProvider gnosisSpecProvider = GnosisSpecProvider.Instance;
+
+        List<ForkActivation> forkActivationsToTest = new()
+        {
+            (ForkActivation)0,
+            (ForkActivation)1,
+            (ForkActivation)(GnosisSpecProvider.ConstantinopoleBlockNumber -1),
+            (ForkActivation)(GnosisSpecProvider.ConstantinopoleBlockNumber),
+            (ForkActivation)(GnosisSpecProvider.ConstantinopoleFixBlockNumber -1),
+            (ForkActivation)(GnosisSpecProvider.ConstantinopoleFixBlockNumber),
+            (ForkActivation)(GnosisSpecProvider.IstanbulBlockNumber -1),
+            (ForkActivation)(GnosisSpecProvider.IstanbulBlockNumber),
+            (ForkActivation)(GnosisSpecProvider.BerlinBlockNumber -1),
+            (ForkActivation)(GnosisSpecProvider.BerlinBlockNumber),
+            (ForkActivation)(GnosisSpecProvider.LondonBlockNumber -1),
+            (ForkActivation)(GnosisSpecProvider.LondonBlockNumber),
+            (1, GnosisSpecProvider.ShanghaiTimestamp - 1),
+            (1, GnosisSpecProvider.ShanghaiTimestamp),
+            (999_999_999, 999_999_999) // far in the future
+        };
+
+        CompareSpecProviders(gnosisSpecProvider, provider, forkActivationsToTest, CompareSpecsOptions.IsGnosis);
+        Assert.That(provider.TerminalTotalDifficulty, Is.EqualTo(GnosisSpecProvider.Instance.TerminalTotalDifficulty));
+        Assert.That(provider.ChainId, Is.EqualTo(BlockchainIds.Gnosis));
+        Assert.That(provider.NetworkId, Is.EqualTo(BlockchainIds.Gnosis));
+
+        provider.GetSpec((1, GnosisSpecProvider.ShanghaiTimestamp - 1)).MaxCodeSize.Should().Be(long.MaxValue);
+
+        /* ToDo uncomment when we have gnosis shapella timestamp
+        provider.GetSpec((1, GnosisSpecProvider.ShanghaiTimestamp)).MaxCodeSize.Should().Be(24576L);
+        provider.GetSpec((1, GnosisSpecProvider.ShanghaiTimestamp)).MaxInitCodeSize.Should().Be(2 * 24576L);*/
+    }
+
 
     [Test]
     public void Mainnet_loads_properly()

src/Nethermind/Nethermind.Specs/GnosisSpecProvider.cs

@@ -0,0 +1,58 @@
+// SPDX-FileCopyrightText: 2023 Demerzel Solutions Limited
+// SPDX-License-Identifier: LGPL-3.0-only
+
+using Nethermind.Core;
+using Nethermind.Core.Specs;
+using Nethermind.Int256;
+using Nethermind.Specs.Forks;
+
+namespace Nethermind.Specs;
+
+public class GnosisSpecProvider : ISpecProvider
+{
+    private GnosisSpecProvider() { }
+
+    public IReleaseSpec GetSpec(ForkActivation forkActivation)
+    {
+        return forkActivation.BlockNumber switch
+        {
+            < ConstantinopoleBlockNumber => GenesisSpec,
+            < ConstantinopoleFixBlockNumber => Constantinople.Instance,
+            < IstanbulBlockNumber => ConstantinopleFix.Instance,
+            < BerlinBlockNumber => Istanbul.Instance,
+            < LondonBlockNumber => Berlin.Instance,
+            _ => forkActivation.Timestamp switch
+            {
+                null or < ShanghaiTimestamp => London.Instance,
+                _ => Shanghai.Instance
+            }
+        };
+    }
+
+    public void UpdateMergeTransitionInfo(long? blockNumber, UInt256? terminalTotalDifficulty = null)
+    {
+        if (blockNumber is not null)
+            MergeBlockNumber = (ForkActivation)blockNumber;
+
+        if (terminalTotalDifficulty is not null)
+            TerminalTotalDifficulty = terminalTotalDifficulty;
+    }
+
+    public ForkActivation? MergeBlockNumber { get; private set; }
+    public ulong TimestampFork => ShanghaiTimestamp;
+    public UInt256? TerminalTotalDifficulty { get; private set; } = UInt256.Parse("8626000000000000000000058750000000000000000000");
+    public IReleaseSpec GenesisSpec => Byzantium.Instance;
+    public long? DaoBlockNumber => null;
+    public ulong NetworkId => BlockchainIds.Gnosis;
+    public ulong ChainId => BlockchainIds.Gnosis;
+    public ForkActivation[] TransitionActivations { get; }
+
+    public const long ConstantinopoleBlockNumber = 1_604_400;
+    public const long ConstantinopoleFixBlockNumber = 2_508_800;
+    public const long IstanbulBlockNumber = 7_298_030;
+    public const long BerlinBlockNumber = 16_101_500;
+    public const long LondonBlockNumber = 19_040_000;
+    public const ulong ShanghaiTimestamp = long.MaxValue;
+
+    public static GnosisSpecProvider Instance { get; } = new();
+}