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@HCastano HCastano released this 22 Nov 22:53
· 488 commits to master since this release
v4.0.0-beta
03474e5

Version 4.0.0-beta

The focus of the first beta release is to establish the stable ABI for the final 4.0.0
release. It means that whilst subsequent beta releases may contain breaking contract
code changes, the ABI will remain the same so that any contract compiled and deployed
with 4.0.0-beta continue to be compatible with all future 4.0.0 versions.

Compatibility

In order to build contracts which use ink! v4.0.0-beta you need to use
cargo-contract v2.0.0-beta.

You can install it as follows:

cargo install cargo-contract --version 2.0.0-beta

You will also need to use a version of pallet-contracts later than 265e3f1 (Nov 3, 2022)
in your node.

The v0.22.1 release of the substrate-contracts-node is
compatible with the ink! 4.0.0-beta release.

Breaking Changes

Constructors and Messages now return LangErrors

We have added a way to handle errors that are neither specific to a particular contract,
nor from the underlying execution environment (e.g pallet-contracts). Instead these are
errors that may come from the smart contracting language itself.

For example, take the case where a contract message is called using an invalid selector.
This is not something a smart contract author should need to define as failure case, nor
is it something that the Contracts pallet needs to be aware of.

Previously, the contract execution would trap if an invalid selector was used, leaving
callers with no way to handle the error gracefully. This can now be handled with the help
of the newly added LangError.

In short, this change means that all ink! messages and constructors now return a
Result<R, LangError>, where R is the original return type. Contract callers can
choose to handle the LangError.

In order to make this error compatible with other languages we have also added a
lang_error field to the metadata format. This will be the central registry of all the
different error variants which languages may want to emit in the future.

Related pull-requests:

Related discussions:

Random function removed

We had to remove ink_env::random with #1442.

This function allowed contract developers getting random entropy.
There is unfortunately no way how this can be done safely enough
with built-in Substrate primitives on-chain currently. We're
following the recommendation of our auditors to remove it.

The alternative right now is to provide random entropy off-chain to
the contract, to use a random entropy oracle, or to have a chain-extension
that does this, in case the chain has a possibility to do so.

We hope to bring this function back in a future release of ink!, the
best hope right now is that it could come back with Sassafras, a block production
protocol for future versions of Polkadot.

Added

  • Allow using Result<Self, Error> as a return type in constructors ‒ #1446
  • Add Mapping::take() function allowing to get a value removing it from storage ‒ #1461

Changed

  • Add support for language level errors (LangError) ‒ #1450
  • Return LangErrors from constructors ‒ #1504
  • Update scale-info requirement to 2.3#1467
  • Merge Mapping::insert(key, val) and Mapping::insert_return_size(key, val) into one method - #1463

Removed

  • Remove ink_env::random function ‒ #1442