cockle

In-browser bash-like shell implemented in a combination of TypeScript and WebAssembly.

Used in the JupyterLite terminal extension.

⚠️ This is an early-stage work in progress and should be considered experimental code. Anything and everything could change at any time.

The commands used here are either built-in commands implemented in TypeScript, or WebAssembly commands compiled into .js and .wasm files. The latter are built by Emscripten-forge and are added to a deployment during the build process.

Emscripten-forge packages containing WebAssembly commands that are currently supported and tested are as follows. Each package contains a single commmand with the same name as the package unless otherwise specified:

• coreutils: multiple core commands including cat, cp, echo, ls, mkdir, mv, rm, touch, uname, and wc
• grep
• lua
• tree
• vim

Build

micromamba env create -f environment-dev.yml
micromamba activate cockle
npm install
npm run build
npm run lint:check

You can use conda, mamba or pixi instead of micromamba here. A copy of micromamba is installed into the cockle environment; this is needed to support the emscripten-wasm32 platform in the demo and tests.

Demo

The cockle repository includes a demo so that you can easily try it out interactively in a web browser. Once you have built cockle, build and run the demo using:

cd demo
npm install
npm run build
npm run serve

then open a browser at the specified URL:

---

Testing

The test directory contains playwright end-to-end tests which can be built and run as follows:

cd test
npm install
npx playwright install --with-deps chromium
npm run build
npm run test
npm run test:report

You can interactively run individual tests using npm run test:ui.

In addition, the demo directory contains separate visual tests that can be run in the same way. Only Linux screenshots are stored within the repository.