PocketIC

PocketIC is a canister smart contract testing solution for the Internet Computer.

GitHub Action

This repository provides a GitHub Action to set up the PocketIC server.

Usage

To use this action in your GitHub workflow, include it as a step in your workflow configuration:

jobs:
  example-job:
    runs-on: ubuntu-latest
    steps:
    - name: Checkout repository
      uses: actions/checkout@v2
    - name: Install PocketIC server
      uses: dfinity/pocketic@main
    - name: Confirm successful installation
      run: "${POCKET_IC_BIN}" --version

The action is designed to run on both ubuntu- and macos- runners.

Specifying a PocketIC server version

You can specify a particular version of the PocketIC server to install using the pocket-ic-server-version input:

    - name: Install PocketIC server
      uses: dfinity/pocketic@main
      with: 
        pocket-ic-server-version: "7.0.0"

Download the PocketIC Server

Alternatively to using the GitHub Action, you can download the PocketIC server binary for a particular version in the Releases tab on the right. For macOS, choose pocket-ic-x86_64-darwin.gz, for Linux, choose pocket-ic-x86_64-linux.gz.

Save the downloaded file as pocket-ic.gz, decompress it, and make it executable:

gzip -d pocket-ic.gz
chmod +x pocket-ic

Finally, export the POCKET_IC_BIN environment variable to point to the (absolute) path of the PocketIC server binary:

export POCKET_IC_BIN="$(pwd)/pocket-ic"

On macOS, you might have to additionally run:

xattr -dr com.apple.quarantine pocket-ic

to bypass the developer verification from Apple. Alternatively, you can open the pocket-ic binary by right clicking on it in the Finder and selecting "Open" from the drop-down menu. Then, confirm opening this application by clicking "Open" in the dialog that pops up.

Using PocketIC

After completion of above steps, you can verify that everything works by running:

./pocket-ic --help

which prints information on how to use the PocketIC server from the command line.

Client Libraries

To write canister tests in your projects with PocketIC, it is recommended to use one of the client libraries. The following libraries are available:

• PocketIC Rust
• PocketIC Python
• Pic JS for JavaScript/TypeScript
• PocketIC Golang

For Rust and Python, make sure to download a server version that is compatible. If you want your client library to be listed here, please post to the Forum!

Why PocketIC?

Canister developers have several options to test their software, but there are tradeoffs:

• Install and test on the mainnet: The 'real' experience, but you pay with real cycles.
• The replica provided by DFX: You get the complete stack of a single IC node. But therefore, you get no cross- or multisubnet functionality, and likely never will. Replica is quite heavyweight too, because the nonessential components are not abstracted away. Furthermore, testing with replica is not deterministic.

Enter PocketIC:

• Deterministic: Synchronous control over the IC's execution environment
• Lightweight: Mocks the consensus and networking layers
• Versatile: Runs as a service on your test system, and accepts HTTP/JSON. This enables:
  • Concurrent and independent IC instances by default - sharing is possible
  • Multi-language support: Anyone can write an integration library against the PocketIC REST-API in any language
• Support for multiple subnets and Xnet calls

Source Code

The source code of the PocketIC server is available on GitHub.

Contributing

Would you like to write canister tests in a different language? The PocketIC server has a JSON/REST interface, against which you may implement a user-facing library in any language.

To see a documentation of the server's endpoints, PocketIC offers an endpoint /api.json, which will return an OpenAPI specification. You can then use tools like the Swagger Editor to display the returned JSON in a more human readable way.

If you decide to contribute, we encourage you to announce it on the Forum!