Pendzl is a library for smart contract development on ink!.
Why use this library?
Which Standard tokens & useful contracts does it provide?
This library was created based on ideas of implementation macro, Storage trait, and storage_item macro that came from openbrush-contracts.
Library allows for reusing implementations of the supported traits for any ink! smart-contract. It’s goal is to be modular and extensible without unnecessary complexity overhead.
Deriving implementations of provided traits is easy. For example, in case of a PSP22:
add a field of of type PSP22Storage and annotate it with #[storage_field] add StorageFieldGetter to storage struct’s derive macro (with the above allows for access to the storage item via .data()) make your contract reuse the PSP22 implementation via #[pendzl::implementation(PSP22)] annotation on top of your contract! The first two steps are to satisfy required boundaries by default implementations - contract’s storage must implement StorageFieldGetter with appropariate generic T (in this case it’s PSP22Storage).
#[pendzl::implementation(PSP22)]
#[ink::contract]
pub mod my_psp22 {
#[ink(storage)]
#[derive(StorageFieldGetter)]
pub struct Contract {
#[storage_field]
psp22: PSP22Data,
}
}
The #[pendzl::implementation(PSP22)] macro implements the PSP22 by including the following code after the macro is expanded:
impl pendzl::contracts::psp22::PSP22Internal for Contract {
fn _total_supply(&self) -> Balance {
pendzl::contracts::psp22::implementation::PSP22InternalDefaultImpl::_total_supply_default_impl(self)
}
}
impl pendzl::contracts::psp22::PSP22 for Contract {
#[ink(message)]
fn total_supply(&self) -> Balance {
pendzl::contracts::psp22::implementation::PSP22DefaultImpl::total_supply_default_impl(self)
}
}
One can override the default_impl of functions from PSP22 and/or PSP22Internal as follows:
const HATED_ACCOUNT: AccountId = <some_account>
#[overrider(PSP22Internal)]
fn _update(
&mut self,
from: Option<&AccountId>,
to: Option<&AccountId>,
amount: &Balance,
)-> Result<(), PSP22Error> {
/// one can use default_impl as in this example or provide completely new implementation.
pendzl::contracts::psp22::implementation::PSP22InternalDefaultImpl::_update_default_impl(self, from, to, amount)
}
#[overrider(PSP22)]
fn approve(
&mut self,
spender: AccountId,
value: Balance,
) -> Result<(), PSP22Error> {
if spender == HATED_ACCOUNT {
return Err(PSP22Error::Custom(String::from("Hated account can not have allowance to spend tokens")));
}
/// one can use default_impl as in this example or provide completly new implementation.
pendzl::contracts::psp22::implementation::PSP22DefaultImpl::approve(self, spender, value)
}
the above overrider functions (marked with #[overrider(…)] ) will be consumed by the #[pendzl::implementation(PSP22)]. As result, the body of the functions will be used to implement the apropariate function in apropariate trait. As showed in above example, one can still use the default implementation if one only wants to add some logic before/after the default implementation or one can fully reimplement the function.
Similar logic applies to storage items. One may not want to use the default PSP22Data and use his PSP22CustomData. This can be achieved in two ways:
To work with the project you need to install ink! toolchain and NodeJS’s dependencies.
pnpm command inside tests/ folderTo build exapmles use
$ bash build_examples.sh
If you want to run tests enter the tests/ foldr and run
$ pnpm i
$ pnpm build:debug
$ pnpm test
Contracts & lang folder in this repository have been audited by Kudelski Security. The audit report can be found here.
Findings that were not resolved have been addressed & explained here.
pendzl is released under the MIT License.