Simple WASM Runner

This is a simple wrapper program to run a WASM runtime (currently one of wasmer or wasmtime) as a runner for things like cargo run. This is useful when wanting to use a target such as wasm32-wasi without the trappings of wasm-pack for example, just running cargo run or cargo test in a package for the wasm32-wasi target. Cargo expects a runner to take the program executable followed by its arguments, and most WASM runtimes have a particular structure to their arguments (e.g., requiring a -- before program arguments).

Usage

Install the runner using cargo:

$ cargo install wasm-runner

You can install directly from the source tree as:

$ cargo install --path=.

After this you can now have a .cargo/config.toml that uses this runner to execute your binaries for WASM targets.

For example:

[target.'cfg(target_arch="wasm32")']
runner = ["wasm-runner", "wasmer"]

This assumes wasmer is in your PATH, but you can also specify the full path if you like.

At this point assuming wasm32-wasi is installed as a target in your toolchain (e.g., rustup target add wasm32-wasi), you can run unit tests or binaries with:

$ cargo --target wasm32-wasi test
$ cargo --target wasm32-wasi run -- some arguments

TODO

• Some integration tests/continuous integration with WASM targeted sample code.
• Ability to customize runtime arguments via environment variables.
• Ability to support other runtimes such as wavm.

License

This project is licensed under the Apache-2.0 License.