README.md

This repository shows how any contract can override the ink_env_config with default environment.

The ink_env_config crate contains types and constants from the ink::env::Environment trait.

The ink_env simulates the ink_env crate. It uses ink_env_config as a dependency.

The contract simulates some contract that uses ink. The developer of the contract wants to use its ink_env_config with custom types. The developer created his local version of the custom-ink-env-config with updated custom types.

// Modified from `[u8; 32]`.
/// The account id type.
pub type AccountId = [u8; 16];

// Modified from `u128`.
/// The type of balances.
pub type Balance = u32;

// Modified from `[u8; 32]`.
/// The type of hash.
pub type Hash = [u8; 64];

The developer patched the dependencies:

[patch."https://github.com/xgreenx/ink-env-config.git"]
ink-env-config = { path = "custom-ink-env-config" }

# If the crate is published on the `crates.io` we can use the following syntax:
# [patch.crates-io]
# ink_env_config = { path = "custom_ink_env_config" }

And after started to use a new types in the contract:

    impl Storage {
        pub fn new() -> Self {
           Self {
               // With default `ink-env-config`
               // total_balance: 123u128,
               // hash_of_child_contract: [1; 32],
               // account_id: [2; 32],
               total_balance: 123u32,
               hash_of_child_contract: [1; 64],
               account_id: [2; 16],
           }
        }
    }

And compiled the contract:

cargo build --manifest-path contract/Cargo.toml