Flutter, Rust and Wasm

Installing Rust:

curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh

Installing wasm-pack to compile Rust code into WASM code:

curl https://rustwasm.github.io/wasm-pack/installer/init.sh -sSf | sh
nano ~/.bash_profile

Then add export PATH="$PATH:$HOME/.cargo/bin"

wasm-pack --version

Creating a new Rust library:

cargo new <LIBRARY_NAME> --lib

Creating a new function to import to Flutter:

Go to src/lib.rs, then replace with something like:

#[no_mangle]
pub extern "C" fn add(a: i32, b: i32) -> i32 {
    a + b
}

Configure Cargo.toml:

Add the following to cargo.toml

[lib]
crate-type = ["cdylib"]
[dependencies]
wasm-bindgen = "0.2"

Building Rust code to WASM package:

wasm-pack build --target web

Open the pkg folder and the compliked .wasm files should be there

Last steps:

Copy the .wasm files to the Flutter project's web/ folder and check the Flutter code in this example project on how to load them.