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Release 04.12.2024: migration guide

This release of =nil; fixes several issues with the =nil; CLI and adds quality-of-life improvements to Nil.js.

Summary of key changes​

General changes​

  • The Cometa service supports displaying Solidity generated code
  • Cometa can now also pinpoint the exact function (in addition to the exact line of code) where an issue occurs
  • The names and descriptions of several errors have been made clearer, simplifying debugging

=nil; CLI changes​

  • The =nil; CLI can use the rpc_endpoint from its config for working with the faucet service and the Cometa service if no separate endpoints are set for either of them
  • The nil contract call-readonly command now returns JSON-formatted output when objects are returned by a call
  • The =nil; CLI can display debug logs and events emitted by smart contracts when using the nil contract call-readonly command
  • The output of the nil config show command has been made more concise

Nil.js changes and smart-contracts changes​

  • Nil.js now provides the contract factory, a Hardhat-like interface for interacting with smart contracts
  • It is possible to estimate gas with Nil.js via the estimateGas() function
  • Nil.js supports sending some feeCredit with external messages, making external deployment of smart contracts more convenient
  • The Wallet.sol contract includes the simpleAsyncCall() function that can forward any feeCredit sent with an external message

Migration of smart contracts​

  • Use simpleAsyncCall() inside Wallet.sol

Previously, the wallet contract in Wallet.sol did not forward feeCredit from any external messages that were sent to it. As a result, the wallet used its balance to pay for the execution of smart contracts across async call chains. This made managing feeCredit complicated when interacting with other smart contracts.

simpleAsyncCall() resolves this issue: the wallet will use Nil.FORWARD_REMAINING to send its own remaining feeCredit across the async call chain. Note that the wallet has one additional overload of simpleAsyncCall() that accepts the feeCredit argument and uses Nil.FORWARD_NONE. This overload is functionally equivalent to the previous asyncCall() function used by the wallet.

Using the new default wallet requires redeploying it in any existing projects built on =nil;.

info

Inside Wallet.sol, the asyncCall() function and its overloads has been removed.

Migration of =nil; CLI commands​

  • Use rpc_endpoint across all services including faucet and Cometa

It is now not necessary to set separate values for rpc_endpoint, cometa_endpoint, and faucet_endpoint in the config file for the =nil; CLI. If cometa_endpoint and faucet_endpoint are empty, =nil; CLI will simply send requests to the RPC endpoint, and these services should still work correctly.

  • Parse improved output of the nil contract call-readonly command

When an object is returned as part of a call, the =nil; CLI can now show JSON-formatted output that demonstrates each object field and value:

Success, result:
(address,string,string,string,string,string,string,string): {"owner": ADDRESS,"profile_name":"Jack Smith","affiliation":"bigco","bio":"bio","role":"engineer","twitter_link":"twitter","linkedin_link":"linkedin","github_link":"github"}

In addition, the CLI now shows logs and events emitted by smart contracts when performing calls.

  • View concise contents of the =nil; CLI config file

The nil config show command now outputs the contents of the CLI config file without any excessive logs:

The config file   : path/to/config.ini
private_key       : PRIVATE_KEY
address           : ADDRESS
rpc_endpoint      : RPC_ENDPOINT

As a result, the output of the command should be easier to parse in scripts.

Migration of Nil.js scripts​

  • Use the new contract factory

Nil.js now exposes a Hardhat-like interface for interacting with smart contracts. After being deployed, a contract can be acquired by calling the getContract() function:

const contract = getContract({
        client: client,
        abi: ABI,
        address: ADDRESS,
        wallet: wallet,
      });

Afterward, simply call methods on the contract object directly instead of sending external messages or internal messages via a wallet:

const res = await contract.read.funcName([]);
const hash = await contract.write.otherFuncName([]);
await waitTillCompleted(client, hash);

The contract factory provides an abstraction over common methods for interacting with already deployed contracts. Using it should make Nil.js code more concise and easy-to-read.

  • Estimate gas in Nil.js

The PublicClient inside Nil.js now contains the estimateGas() function that can be used to estimate the feeCredit for performing a call or sending a message to a specific address. There is no longer a need to evaluate feeCredit manually or by using the =nil; CLI.

  • Send feeCredit with an external message

It is now also possible to specify the exact amount of feeCredit send with an external message. Previously, this value was hard-coded. This change provides greater control over how much tokens contracts pay for their execution when called externally.

Migration of Hardhat projects​

No specific changes have to be made to existing Hardhat projects.