evm-breakpoints

Human-friendly interface for Ethereum VM breakpoints - debugging helper.

Example of library usage in tests:

const evm = reuqire('evm-breakpoints');
 
const logger = evm.breakpoint().add({
  contractFile: "./build/contracts/Simple.json", // we should take full compilation info from the given file
  lines: [21] // multiple lines can be specified as breakpoints
});
 
const debug = evm.iterator(web3, txHash, logger);
while (!debug.stopped()) {
  console.log(debug.get());
  debug.next();
}

please see examples/truffle for a full example of debugging local variables.

Example of library usage in web:

In web environment, you need to compile the contract, and then provide iterator source map from compiled version

var evm = window.evmBreakpoints;
evm
  .contract({ source: contractSoure, compiler: "latest"  })
  .on('ready', function(compiled) {
     var json = compiled.contracts[contractName];
     var logger = evm.breakpoint().add({ source, sourceMap: json.srcmapRuntime, lines: [21] });
     var debug = evm.iterator(web3, txHash, logger);
     while (!debug.stopped()) {
       console.log(debug.get());
       debug.next();
     }
  })
  .on('error', console.error);

please see examples/web/index.html for a full example of debugging local variables.

Disclaimer

Work of the library is based on experimental web3.debug.traceTransaction, so please keep following the updates

• HTTP RPC "debug" api must be enabled https://github.com/ethereum/go-ethereum/wiki/Management-APIs#debug_tracetransaction

• If you are receiving Error: missing trie node, in order to use trace api of geth you have to synchronize your node with --syncmode full

License

MIT. Anyone can copy, change, derive further work from this repository without any restrictions.