NEO debugger tools for NEO smart contracts.
A suite of development tools for NEO smart contracts.
Includes a cli disassembler and a GUI debugger. A helper library that helps loading .avm files and create and load .neomap files is also included, and can be used to create other dev tools.
(click picture to view video)
- A modified NEO compiler to compile C# into an
.avmfile and, at same time, emit a.neomapfile. - A debugger IDE will load the
.avmand disassemble it into readable opcodes. - The debugger IDE can also run or step through either the assembly code or the original source (if the
.neomapfile is present in same directory as the.avm) - The debugger will also emulate the smart contracts' API that interacts with the Blockchain (like Storage, Transactions, Blocks)
- Get this code and open the solution in Visual Studio.
- Compile the solution and find the compiled NEON.exe path (should be in $(SolutionPath)\NEO-Compiler\bin\Debug).
- Replace the path of your old NEON compiler to the new compiler path.
- When you compile a smart contract, it will accordingly use the debugger compiler and produce (next to the
.avm) the map file which you need to step through the code.
- Supports any NEO
.avm, regardless of the language / compiler used - Source viewer with syntax highlight powered by ScintillaNET
- Run, step and set breakpoints in order to debug smart contracts
- Toggle between source code and assembly code
- Debugging ASM, C# and Python only for now (see section below how to add new languages)
- Windows only for now, using .NET Framework / Winforms / ScintillaNET
- Smart contract source is limited to a single file for now
- Not possible yet to inspect variable values
- Some NEO syscalls / APIs not supported yet (work in progress)
Open the .avm file in the NEO-dbg GUI application.
This will show either assembly code for the .avm or C# if a debug map file was found.
Currently the only way to generate a .neomap file is to compile the smart contracts with the modified NeoN compiler included in this repository.
| Key | Action | Comments |
|---|---|---|
| F5 | Executes the smart contract | |
| F10 | Steps through the smart contract | |
| F12 | Toggles between assembly and source code | Only works when a .neomap file is available |
A single smart contract can have different results and behaviours, depending on the inputs passed to it.
So, when debugging a contract, it is necessary to be able to specify the inputs. Currently this is done via a .json file that resides in the same folder as the debugger executable.
This file should have the same name as the .avm file. So if your contract file is hello.avm, make sure the input file is called hello.json.
Here's a example contract that takes a string and array of objects as argument.
using Neo.SmartContract.Framework;
using Neo.SmartContract.Framework.Services.Neo;
using System;
using System.Numerics;
namespace Example {
public class Calculator : SmartContract {
public static int Main(string operation, params object[] args) {
int arg0 = (int)args[0];
int arg1 = (int)args[1];
if (operation == "add") { return arg0 + arg1; }
if (operation == "sub") { return arg0 - arg1; }
return -1;
}
}
}And here is how to define inputs for it via the .json file.
{
"contract": {
"params": "0710",
"inputs": [
{
"name": "add(5,3)",
"params": ["add", [5, 3]]
},
{
"name": "sub(7,2)",
"params": ["sub", [7, 2]]
},
]
}
}The different inputs in this file will appear in the debugger when you execute the contract.
Note that the "name" field here can be anything, it is just used to display in the debugger GUI. Optionally you can modify the inputs in the text box.
Inputs follow the json specs, so a "5" will have a different meaning from a 5.
| Type | Examples | Comments |
|---|---|---|
| Number | "params": [5] | |
| String | "params": ["5", "hello"] | |
| Bool | "params": [true] | |
| Byte array | "params": ["0xFF03DA22", [10, 20, 44]] | Either specified as an hexadecimal string or as an array of decimal numbers |
The debugger supports emulation of the Storage API, meaning Storage.Put and Storage.Get work fine when debugging.
The actual data is stored in a file with extension .store, in same folder as the .avm. If required to reset the smart contract storage, it's fine to delete this file.
In the latest version it is possible to view the storage contents using the Debug>Storage menu.
The current version does support sending virtual NEO and GAS to the smart contract, emulating an asset transfer.
NEO smart contracts can be coded in many different languages, and in theory, this compiler already supports any language as long as a .neomap file exists in the same directory as the .avm file.
However, in order to be able to debug an compiled .avm file, the compiler used must be able to emit those map files during compilation.
The table below lists the current supported languages / compilers.
| Language | Compiler | Comments |
|---|---|---|
| C# | neon | Only supported if using the neon version from this repository. |
| Python | neo-boa |
To add other languages it would be necessary to modify compilers to emit a .neomap.
The .neomap file format is json and consists of a compiler section that includes info about the compiler used, files section including list of source code files used to generate the avm, an avm section including an MD5 hash of the compiled avm, plus an map section used to map start and end byte offsets to source code.
{
"compiler": {
"name": "neo-boa",
"version": "0.1"
},
"files": [
{
"url": "D:\\MySmartContracts\\HelloWorld.py",
"id": "1"
}
],
"avm": {
"name": "AddTest",
"hash": "c485df80dc0551162a344ed1617956e5"
},
"map": [
{
"start": 17,
"end": 43,
"file": 1,
"line": 10
},
{
"start": 44,
"end": 61,
"file": 1,
"line": 11
},
{
"start": 62,
"end": 88,
"file": 1,
"line": 13
},
{
"start": 89,
"end": 100,
"file": 1,
"line": 14
}
]
}A developer shell is also included and can be used to emulate and debug NEO smart contracts from the terminal.
The smart contract inputs should also be passed as a JSON string, same as in the debugger GUI.
If using Linux or OSX, Mono is required.
The NEO emulator library makes it easy to create your own unit tests for smart contracts.
It's not necessary to download the debugger and the others tools if you just need Unit Testing.
In that case, just install the Neo.Emulator, which is available as a Nuget package.
PM> Install-Package Neo.Emulator
using System.IO;
using LunarParser;
using Neo.Emulator;
using NUnit.Framework;
[TestFixture]
public class ContractTests
{
private static NeoEmulator emulator;
// load the .avm file before tests run
[OneTimeSetUp]
public void Setup()
{
var path = TestContext.CurrentContext.TestDirectory.Replace("ICO-Unit-Tests", "ICO-Template");
Directory.SetCurrentDirectory(path);
var avmBytes = File.ReadAllBytes("ICOContract.avm");
emulator = new NeoEmulator(avmBytes);
}
[Test]
public void TestSymbol()
{
// create the inputs to be passed to the NEO smart contract
var inputs = DataNode.CreateArray();
inputs.AddValue("symbol");
inputs.AddValue(null);
// reset the Emulator then run it
emulator.Reset();
emulator.Run(inputs);
// obtain the smart contract output
var result = emulator.GetOutput();
Assert.NotNull(result);
// validate output
var symbol = result.GetString();
Assert.IsTrue(symbol.Equals("DEMO"));
}
} In the folder ICO Template you can find an example of a complex .json input file.
Included is also a small project to demonstrate unit tests of the demo project.
- Transactions emulation (In progress)
- Debugger map generation for Java / Python / others
Created by Sérgio Flores (http://lunarlabs.pt/).
Credits also go to the NEO team(http://neo.org), as a large part of this work was based on their NEO compiler and NEO VM.
This project is released under the MIT license, see LICENSE.md for more details.