ink-wrapper

ink-wrapper is a tool that generates type-safe code for calling a substrate smart contract based on the metadata (.json) file for that contract.

Installation

Install the tool from crates.io:

cargo +nightly-2023-04-19 install ink-wrapper --locked --force

Note that this uses nightly-2023-04-19. You will need to install the toolchain first. You may try with just +nightly to use whatever nightly you already have installed, but this particular version should work. The crate will most likely compile on another toolchain, but generate broken code afterwards, see udoprog/genco#39.

Usage

Note on compatibility.

The last release compatible with aleph_client is version 0.6.0. Note though that it's compatible with aleph-client in version 3.0.0 as this is the last version available in crates.io. We do not guarantee it will work with Testnet or Mainnet since their runtimes may differ in ways that are not compatible with aleph_client 3.0.0.

Current release focuses on compatibility with drink.

Future releases will try to address the support for live chains.

Setup

Given some metadata file like my_contract.json run the tool and save the output to a file in your project:

ink-wrapper -m my_contract.json > src/my_contract.rs

We only take minimal steps to format the output of the tool, so we recommend that you run it through a formatter when (re)generating:

ink-wrapper -m my_contract.json | rustfmt --edition 2021 > src/my_contract.rs

The output should compile with no warnings, please create an issue if any warnings pop up in your project in the generated code.

Make sure the file you generated is included in your module structure:

mod my_contract;

DRink!

Add the following to your `Cargo.toml:

[dependencies]
drink = "0.8.6"
ink_primitives = "4.3.0"
ink-wrapper-types = { version = "0.7.0", default-feauters = false, features = [ "drink" ] }
scale = { package = "parity-scale-codec", version = "3", default-features = false, features = [ "derive" ] }

After generating the wrappers, the my_contract will contain Instance struct which represents the contract's state.

The easiest way to write a test is to use drink's unit test macro which will set up the drink::session::Sessin<MinimalRuntime> object:

// Auto-generated wrappers need to be added to the crate.
mod my_contract;

// Minimal imports
use ink_wrapper_types::{Connection, ToAccountId};
use drink::{session::Session, AccountId32};

#[drink::test]
fn my_test(mut session: Session) {
    // Upload code to DRink! backend
    let _code_hash = session.upload_code(my_contract::upload()).expect("Upload to succeed");

    // Instantiate the contract.
    let address = session.instantiate(my_contract::Instance::new(1000))
        .expect("No pallet-contract errors")
        .result // AccountId, address, of the new instance
        .to_account_id() // Map to ink_primitives type
        .into();

    // Now we can call contract's methods. They're provided by the trait `my_contract::MyContract` (depends on your actual contract name)
    use my_contract::MyContract as _;

    // Construct the call object.
    let exec_call = address.some_exec_call();
    
    // Execute it.
    let res = session.execute(exec_call);
}

For more comprehensive examples on actual contract wrappers, see tests directory.

aleph_client (deprecated from 0.7.0)

You will need the following dependencies for the wrapper to work:

ink-wrapper-types = "0.6.0"
scale = { package = "parity-scale-codec", version = "3", default-features = false, features = ["derive"] }
ink_primitives = "4.2.1"

# You only need this one if you have messages of the form `Trait::message`, like the ones generated by openbrush, for
# example.
async-trait = "0.1.68"

# This one is optional, but you most likely need it as well if you're using the default `aleph_client` implementation
# for actually making calls. Otherwise, you will need to implement `ink_wrapper_types::Connection` and
# `ink_wrapper_types::SignedConnection` yourself.
aleph_client = "3.0.0"

Basic usage

With that, you're ready to use the wrappers in your code. The generated module will have an Instance struct that represents an instance of your contract. You can either talk to an existing instance by converting an account_id to an Instance:

let account_id: ink_primitives::AccountId = ...;
let instance: my_contract::Instance = account_id.into();

Or (assuming the contract code has already been uploaded) create an instance using one of the generated constructors:

let instance = conn.instantiate(my_contract::Instance::some_constructor(arg1, arg2)).await?;

And then call methods on your contract:

let result = conn.read(instance.some_getter(arg1, arg2)).await?;
let tx_info = conn.exec(instance.some_mutator(arg1, arg2)).await?;

Note that any methods that have names like Trait::method_name will be grouped into traits in the generated module. You might encounter this if you're using openbrush, for example their PSP22 implementation generates method names like PSP22::balance_of. You need to use the generated traits to access these:

use my_contract::PSP22 as _;
conn.read(instance.balance_of(account_id)).await?

In the examples above, conn is anything that implements ink_wrapper_types::Connection (and ink_wrapper_types::SignedConnection if you want to use constructors or mutators). Default implementations are provided for the connection in aleph_client.

Events

ink_wrapper_types::Connection also allows you to fetch events for a given TxInfo:

use ink_wrapper_types::Connection as _;

let tx_info = conn.exec(instance.some_mutator(arg1, arg2)).await?;
let all_events = conn.get_contract_events(tx_info).await?;
let contract_events = all_events.for_contract(instance);
let sub_contract_events = all_events.for_contract(sub_contract);

The all_events object above may contain events from multiple contracts if the contract called into them. In that case, you can filter and parse these events by calling for_contract on it, with the various contracts you're interested in.

Code upload

If you provide a compile-time path to the compiled WASM:

ink-wrapper -m my_contract.json --wasm-path ../contracts/target/ink/my_contract.wasm

you will also be able to use the generated wrapper to upload the contract:

conn.upload(my_contract::upload()).await

Note, that the upload function will return Ok(TxInfo) so long as the transaction was submitted successfully and the code hash of the metadata matches the uploaded code. If the code already existed on the chain, no error is returned. You can verify this condition yourself by looking at the events at the returned TxInfo and checking if they contain a CodeStored event.

Example

Look at tests in the project's repo for a fuller example. Note that tests/drink is missing the actual wrappers, which are normally generated when testing. The easiest way to regenerate them is by running make all-dockerized (requires docker) - see Development for more on that.

Development

Use the commands provided in the Makefile to replicate the build process run on CI:

make help

The most hassle-free is to just run everything in docker:

make all-dockerized

If you have the tooling installed on your host and start a node yourself, you can also run the build on your host:

make all

In case there are any runaway containers from all-dockerized you can kill them:

make kill