There are two contracts:

├── contracts
│   ├── caller
│   └── target

We want to call the target contract via caller, using call_with_function_selector in Sway, and .call_low_level_call() in the Rust SDK.

./0_build_contracts.sh

Im using forc 0.42.1 and as indicated in fuel-toolchain.toml.

the CallerContract uses a method straight out of the fuels-rs repo.

The low level caller contract "CallerContract" is the same as: https://github.com/FuelLabs/fuels-rs/blob/master/packages/fuels/tests/contracts/low_level_caller/src/main.sw

The TargetContract has a few simple methods: set() and get() to set storage variables and a get method to check if the values were stored correctly.

I have annotated the ./tests/harness.rs file with the methods that work and ones that dont.

To test:

Using fuel-core version 0.19.1

fuel-core run --ip 127.0.0.1 --port 4000 --db-type in-memory

Using the build in wallet:

pub const WALLET_FROM_FUEL_CORE: &str =
    "de97d8624a438121b86a1956544bd72ed68cd69f2c99555b08b1e8c51ffd511c";

from inside project root directory.

./1_deploy_contracts.sh

OR using cargo:

cargo test --package llcall_testing --test integration_tests -- deploy_contracts --exact --show-output

test_set0_get0 using low level call - This one works:

cargo test --package llcall_testing --test integration_tests -- test_set0_get0 --exact --show-output

test_set1_get1 using low level call - This Fails:

cargo test --package llcall_testing --test integration_tests -- test_set1_get1 --exact --show-output

test_set2_get2 using low level call - This Fails:

cargo test --package llcall_testing --test integration_tests -- test_set2_get2 --exact --show-output

test_set3_get3 using low level call - This Fails: attempts to populate a struct as call data:

DemoStruct {
    a: true,
    b: [1, 2, 3],
    c: 22u64,
}

cargo test --package llcall_testing --test integration_tests -- test_set3_get3 --exact --show-output

Call set3 directly with a populated DemoStruct and read back - This works.

cargo test --package llcall_testing --test integration_tests -- direct_call_set3_get3 --exact --show-output