[Add] DebugApplicationEngine

src/neo-build/Directory.Build.props

@@ -41,4 +41,8 @@
     <None Include="../../../.neo/README.md" Pack="true" Visible="false" PackagePath=""/>
   </ItemGroup>
 
+  <ItemGroup>
+    <Compile Include="../../IsExternalInit.cs" Visible="false" />
+  </ItemGroup>
+
 </Project>

src/neo-build/Neo.Build.Core/Attributes/ContractScriptHashAttribute.cs

@@ -0,0 +1,26 @@
+// Copyright (C) 2015-2025 The Neo Project.
+//
+// ContractScriptHashAttribute.cs file belongs to the neo project and is free
+// software distributed under the MIT software license, see the
+// accompanying file LICENSE in the main directory of the
+// repository or http://www.opensource.org/licenses/mit-license.php
+// for more details.
+//
+// Redistribution and use in source and binary forms with or without
+// modifications are permitted.
+
+using System;
+
+namespace Neo.Build.Core.Attributes
+{
+    [AttributeUsage(AttributeTargets.Class | AttributeTargets.Interface, AllowMultiple = false)]
+    public class ContractScriptHashAttribute(
+        UInt160 scriptHash) : Attribute
+    {
+        public UInt160 ScriptHash { get; } = scriptHash;
+
+        public ContractScriptHashAttribute(
+            string scriptHash) : this(UInt160.Parse(scriptHash))
+        { }
+    }
+}

src/neo-build/Neo.Build.Core/Builders/BlockBuilder.cs

@@ -9,9 +9,9 @@
 // Redistribution and use in source and binary forms with or without
 // modifications are permitted.
 
-using Neo.Build.Core.Factories;
 using Neo.Builders;
 using Neo.Cryptography;
+using Neo.Extensions.Factories;
 using Neo.Network.P2P.Payloads;
 using System;
 using System.Linq;

src/neo-build/Neo.Build.Core/Extensions/ScriptBuilderExtensions.cs

@@ -0,0 +1,51 @@
+// Copyright (C) 2015-2025 The Neo Project.
+//
+// ScriptBuilderExtensions.cs file belongs to the neo project and is free
+// software distributed under the MIT software license, see the
+// accompanying file LICENSE in the main directory of the
+// repository or http://www.opensource.org/licenses/mit-license.php
+// for more details.
+//
+// Redistribution and use in source and binary forms with or without
+// modifications are permitted.
+
+using Neo.Build.Core.Helpers;
+using Neo.Extensions;
+using Neo.SmartContract;
+using Neo.VM;
+using System;
+using System.Linq.Expressions;
+
+namespace Neo.Build.Core.Extensions
+{
+    public static class ScriptBuilderExtensions
+    {
+        public static ScriptBuilder EmitContractCall<T>(this ScriptBuilder builder, Expression<Action<T>> expression)
+            where T : class
+        {
+            var methodCallBody = (MethodCallExpression)expression.Body;
+            var methodName = methodCallBody.Method.Name;
+            var scriptHash = NeoBuildAttributeHelper.ExtractContractScriptHash(typeof(T));
+
+            if (char.IsLower(methodName[0]) == false)
+                methodName = char.ToLower(methodName[0]) + methodName[1..];
+
+            for (var i = methodCallBody.Arguments.Count - 1; i >= 0; i--)
+            {
+                var argumentValue = Expression.Lambda(methodCallBody.Arguments[i])
+                    .Compile()
+                    .DynamicInvoke();
+                builder.EmitPush(argumentValue);
+            }
+
+            builder.EmitPush(methodCallBody.Arguments.Count);
+            builder.Emit(OpCode.PACK);
+            builder.EmitPush(CallFlags.All);
+            builder.EmitPush(methodName);
+            builder.EmitPush(scriptHash);
+            builder.EmitSysCall(ApplicationEngine.System_Contract_Call);
+
+            return builder;
+        }
+    }
+}

src/neo-build/Neo.Build.Core/Extensions/SmartContract/ApplicationEngineExtensions.cs

@@ -0,0 +1,116 @@
+// Copyright (C) 2015-2025 The Neo Project.
+//
+// ApplicationEngineExtensions.cs file belongs to the neo project and is free
+// software distributed under the MIT software license, see the
+// accompanying file LICENSE in the main directory of the
+// repository or http://www.opensource.org/licenses/mit-license.php
+// for more details.
+//
+// Redistribution and use in source and binary forms with or without
+// modifications are permitted.
+
+using Neo.Build.Core.Exceptions;
+using Neo.Build.Core.Helpers;
+using Neo.Build.Core.SmartContract.Debugger;
+using Neo.Persistence;
+using Neo.SmartContract;
+using Neo.SmartContract.Native;
+using Neo.VM;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Linq.Expressions;
+
+namespace Neo.Build.Core.Extensions.SmartContract
+{
+    public static class ApplicationEngineExtensions
+    {
+        public static VMState ExecuteScript(this ApplicationEngine engine, Script script)
+        {
+            engine.LoadScript(script);
+            return engine.Execute();
+        }
+
+        public static VMState ExecuteScript<T>(this ApplicationEngine engine, Expression<Action<T>> expression)
+            where T : class
+        {
+            engine.LoadScript(expression);
+            return engine.Execute();
+        }
+
+        public static void LoadScript<T>(this ApplicationEngine engine, Expression<Action<T>> expression)
+            where T : class
+        {
+            using var sb = new ScriptBuilder()
+                .EmitContractCall(expression);
+            engine.LoadScript(sb.ToArray());
+        }
+
+        public static ContractState GetContractState<T>(this ApplicationEngine engine)
+            where T : class
+        {
+            var scriptHash = NeoBuildAttributeHelper.ExtractContractScriptHash(typeof(T));
+            if (scriptHash != UInt160.Zero)
+                return engine.GetContractState(scriptHash);
+            else
+            {
+                var contractName = NeoBuildAttributeHelper.ExtractContractName(typeof(T));
+                return engine.GetContractState(contractName);
+            }
+        }
+
+        public static ContractState GetContractState(this ApplicationEngine engine, string contractName)
+        {
+            var snapshot = engine.SnapshotCache;
+
+            foreach (var contractState in NativeContract.ContractManagement.ListContracts(snapshot))
+            {
+                if (contractName.Equals(contractState.Manifest.Name))
+                    return contractState;
+            }
+
+            // TODO: Make this exception it own class
+            throw new NeoBuildException($"Contract '{contractName}' not found.", NeoBuildErrorCodes.Contracts.ContractNotFound);
+        }
+
+        public static ContractState GetContractState(this ApplicationEngine engine, int id)
+        {
+            var snapshot = engine.SnapshotCache;
+
+            foreach (var contractState in NativeContract.ContractManagement.ListContracts(snapshot))
+            {
+                if (contractState.Id == id)
+                    return contractState;
+            }
+
+            // TODO: Make this exception it own class
+            throw new NeoBuildException($"Contract with Id '{id}' not found.", NeoBuildErrorCodes.Contracts.ContractNotFound);
+        }
+
+        public static ContractState GetContractState(this ApplicationEngine engine, UInt160 scriptHash)
+        {
+            var snapshot = engine.SnapshotCache;
+
+            foreach (var contractState in NativeContract.ContractManagement.ListContracts(snapshot))
+            {
+                if (contractState.Hash == scriptHash)
+                    return contractState;
+            }
+
+            // TODO: Make this exception it own class
+            throw new NeoBuildException($"Contract '{scriptHash}' was not found.", NeoBuildErrorCodes.Contracts.ContractNotFound);
+        }
+
+        public static HashSet<DebugStorage> GetContractStorage<T>(this ApplicationEngine engine, byte[]? prefix = null, SeekDirection seekDirection = SeekDirection.Forward)
+            where T : class
+        {
+            prefix ??= [];
+
+            var contractState = engine.GetContractState<T>();
+            var key = StorageKey.CreateSearchPrefix(contractState.Id, prefix);
+            var snapshot = engine.SnapshotCache;
+
+            return [.. snapshot.Find(key, seekDirection).Select(static s => new DebugStorage(s.Key, s.Value, StorageEvent.Read))];
+        }
+    }
+}