Storage is not initialized and will revert on `read()`

[hal3e]

Given the contract code:

contract;

storage {
    x: u64 = 64,
}

abi MyContract {
    #[storage(read)]
    fn get_value() -> u64;
}  
  
impl MyContract for Contract {
    #[storage(read)]
    fn get_value() -> u64 {
        storage.x.read()
    }
}

storage.x.read() will revert because we call unwrap() on a None value.

To recreate follow the steps from the fuel book: https://fuelbook.fuel.network/master/quickstart/smart-contract.html, and use the contract example above.

[tritao]

Cannot repro this, added a new test to the suite based on the contract provided: https://github.com/FuelLabs/sway/commit/98d8d78a6e76c6c927ace3b68138fe7b37d5ee03

It runs successfully, deploys the contract, calls get_value and returns the expected initial value of 64 in storage.

[hal3e]

I tried it again.

• Created a new project with forc init.
• Added tests with cargo generate --init fuellabs/sway templates/sway-test-rs --name {SOME_NAME}.
• Built with forc 0.40.0.
• Ran tests with cargo test ( used fuels-rs 0.42 and fuel-core 0.18.2)

I still get the Revert(0) panic

[tritao]

@hal3e Followed your instructions and still everything passes.

running 1 test
test can_get_contract_id ... ok

test result: ok. 1 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.33s

I guess the only difference is I'm on a slightly more recent Forc version (733d9b58865b71cbfdd3f50e0d88e57487856833):

forc 0.40.1
Fuel Orchestrator

Do I need any custom changes to the harness.rs to trigger it or just the default generated version triggers it on your end?

[hal3e]

Thanks for looking into this.

You have to call the method. Here is what I did:

use fuels::{prelude::*, types::ContractId};

// Load abi from json
abigen!(Contract(
    name = "MyContract",
    abi = "out/debug/{SOME_NAME}-abi.json"
));

async fn get_contract_instance() -> (MyContract<WalletUnlocked>, ContractId) {
    // Launch a local network and deploy the contract
    let mut wallets = launch_custom_provider_and_get_wallets(
        WalletsConfig::new(
            Some(1),             /* Single wallet */
            Some(1),             /* Single coin (UTXO) */
            Some(1_000_000_000), /* Amount per coin */
        ),
        None,
        None,
    )
    .await;
    let wallet = wallets.pop().unwrap();

    let id = Contract::load_from(
        "./out/debug/predicate-true.bin",
        LoadConfiguration::default(),
    )
    .unwrap()
    .deploy(&wallet, TxParameters::default())
    .await
    .unwrap();

    let instance = MyContract::new(id.clone(), wallet);

    (instance, id.into())
}

#[tokio::test]
async fn can_get_value() {
    let (instance, _id) = get_contract_instance().await;

    instance.methods().get_value().call().await.unwrap();
}

SOME_NAME - use your project name. FYI I also tried the test with forc 0.40.1 and I get the same revert.

[tritao]

Cool, thanks for the help.

I can repro it now:

thread 'can_get_contract_id' panicked at 'called `Result::unwrap()` on an `Err` value: RevertTransactionError { reason: "Revert(0)", revert_id: 0, receipts: [Call { id: 0000000000000000000000000000000000000000000000000000000000000000, to: 6d24908d1dda644c74a7071206305b2015c5da47cd927d9da3bd3f0bd3ba6a37, amount: 0, asset_id: 0000000000000000000000000000000000000000000000000000000000000000, gas: 1000000, param1: 3444169300, param2: 1, pc: 11624, is: 11624 }, Revert { id: 6d24908d1dda644c74a7071206305b2015c5da47cd927d9da3bd3f0bd3ba6a37, ra: 0, pc: 11908, is: 11624 }, ScriptResult { result: Revert, gas_used: 319 }] }', tests/harness.rs:41:49

Not really sure what's going on, the same test works when run on the compiler test suite (which also runs and calls the method, and returns the correct value).