Fixing admin contract

Now that we know what we want to achieve, we can start by aligning the contract we already have to become an admin contract. It is primarily fine at this point, but we want to do a cleanup.

Cleaning up queries

The first thing to do is to get rid of the Greet query - it was good as a starter query example, but it has no practical purpose and only generates noise.

We want to remove the unnecessary variant from the query enum:

#![allow(unused)]
fn main() {
use cosmwasm_schema::{cw_serde, QueryResponses};
use cosmwasm_std::Addr;

#[cw_serde]
pub struct InstantiateMsg {
    pub admins: Vec<String>,
    pub donation_denom: String,
}

#[cw_serde]
pub enum ExecuteMsg {
    Leave {},
    Donate {},
}

#[cw_serde]
pub struct AdminsListResp {
    pub admins: Vec<Addr>,
}

#[cw_serde]
#[derive(QueryResponses)]
pub enum QueryMsg {
    #[returns(AdminsListResp)]
    AdminsList {},
}
}

Then we also remove the invalid path in the query dispatcher:

#![allow(unused)]
fn main() {
pub fn query(deps: Deps, _env: Env, msg: QueryMsg) -> StdResult<Binary> {
    use QueryMsg::*;

    match msg {
        AdminsList {} => to_binary(&query::admins_list(deps)?),
    }
}
}

Finally, we remove the irrelevant handler from the contract::query module. We also need to make sure all references to it are gone (eg. if there are any in the tests).

Generating the library output

At the very beginning of the book, we set the crate-type in Cargo.toml as "cdylib". It was required to generate the wasm output, but it comes with a drawback - the dynamic libraries, as this cannot be used as dependencies in other crates. It was not a problem before, but in practice we often want to depend contract on others to get access to some types of them - for example, defined messages.

Good for us. It is easy to fix. You might notice that the crate-type is an array, not a single string. The reason for that is that our project can emit several targets - in particular, we can add there the default "rlib" crate type to make it generate a "rust library" output - which is what we need to use as a dependency. Let's update our Cargo.toml:

[package]
name = "admin"
version = "0.1.0"
edition = "2021"

[lib]
crate-type = ["cdylib", "rlib"]
# 
# [features]
# library = []
# 
# [dependencies]
# cosmwasm-std = { version = "1.1.4", features = ["staking"] }
# serde = { version = "1.0.103", default-features = false, features = ["derive"] }
# cw-storage-plus = "0.15.1"
# thiserror = "1"
# schemars = "0.8.1"
# cw-utils = "0.15.1"
# cosmwasm-schema = "1.1.4"
# 
# [dev-dependencies]
# cw-multi-test = "0.15.1"

Also, note I changed the contract name - "contract" is not very descriptive, so I updated it to "admin".

Project structure

Last but not least - we want to better structure our project. So far, we have only one contract, so we just worked on it as a whole project. Now we want some directory tree that reflects relations between contracts we create.

First, create a directory for the project. Then we want to create a "contracts" subdirectory in it. It is not technically required from Rust's POV, but there are tools in our environment, like the workspace optimizer, which would assume it is where it should look for a contract. It is a common pattern you will see in CosmWasm contracts repos.

Then we copy the whole project directory from the previous chapter into the contracts, renaming it to admin.

Finally, we want to couple all our projects (for now, it is just one, but we know there will be more there). To do so, we create the workspace-level Cargo.toml file in the top-level project directory:

[workspace]
members = ["contracts/*"]
resolver = "2"

This Cargo.toml differs slightly from the typical project-level one - it defines the workspace. The most important field here is the members - it defines projects being part of the workspace.

The other field is the resolver. It is something to remember to add - it instructs cargo to use version 2 of the dependency resolver. This has been the default for non-workspaces since Rust 2021, but because of compatibility reasons, the default couldn't be changed for workspaces - but it is advised to add it to every single newly created workspace.

The last field which might be useful for workspaces is exclude - it allows to create projects in the workspace directory tree, which is not a part of this workspace - we will not use it, but it is good to know about it.

Now just for clarity, let's see the top-level directory structure:

.
├── Cargo.lock
├── Cargo.toml
├── contracts
│  └── admin
└── target
   ├── CACHEDIR.TAG
   └── debug

You can see the target directory and Cargo.lock files existing in the tree - it is because I already built and ran tests for the admin contract - in Rust workspaces, `cargo`` knows to build everything in the top level, even if it would be built from the inner directory.