5. Build and test components

cargo install cargo-binstall
cargo binstall cargo-component wasm-tools warg-cli wkg --locked --no-confirm --force

# Configure default registry
wkg config --default-registry wa.dev

# Allow publishing to a registry
#
# if WSL: `warg config --keyring-backend linux-keyutils`
warg key new

Build components

Run the following command in your terminal to build your component. Exclude WASI_BUILD_DIR to build all components.

WASI_BUILD_DIR=components/evm-price-oracle make wasi-build

This command will build any components present in the /components directory, as well as auto-generate bindings and compile the components to WASM. The output will be placed in the compiled directory.

make build

Testing and debugging

You can use the following command to execute the component using Cast. This command is handy for testing components without having to deploy WAVS.

An ID of 1 is Bitcoin. Nothing will be saved on-chain, just the output of the component is shown.

make wasi-exec

This command runs your component locally in a simulated environment and lets you easily view print statements for debugging. Running this command in the oracle example will print the information from the oracle component code. Visit the component walkthrough for more information on logging during testing and production.

Upon successful execution, you should receive a result similar to the following:

resp_data: Ok(PriceFeedData { symbol: "BTC", timestamp: "2025-02-14T01:23:03.963Z", price: 96761.74120116462 })
 INFO Fuel used:
1477653

Result (hex encoded):
7b2273796d626f6c223a22425443222c2274696d657374616d70223a22323032352d30322d31345430313a32333a30332e3936335a222c227072696365223a39363736312e37343132303131363436327d

Result (utf8):
{"symbol":"BTC","timestamp":"2025-02-14T01:23:03.963Z","price":96761.74120116462}

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