Template Wasm wrapper

This is a guide on WebAssembly (Wasm) wrapper development, from writing your wrapper to deploying it to decentralized storage.

Prerequisites

You'll need these dependencies installed globally own your machine before you begin:

• nvm
• yarn
• docker
• docker-compose

Setting up the template

To set up a sample project, run:

npx polywrap create wasm assemblyscript my-wrapper
cd my-wrapper

Then install dependencies with:

nvm install && nvm use && yarn

Project files

Inside the src/ folder are two files that you'll be working on most:

• index.ts: Wrapper implementation
• schema.graphql: Wrapper types

Build, deploy and test (template project)

In this section, we will:

• Build the template wrapper which can getData from our smart contract
• Build a simpleStorage contract that can get and set data
• Deploy them to a local IPFS node and Ethereum node, respectively
• Run an end-to-end test to confirm that the wrapper getData from the contract

Building wrapper and sample smart contract

To build the wrapper, run:

yarn build

This will output it in the ./build/* folder and also build the sample smart contract that your wrapper will interact with.

Setting up a local test environment and deploying

You will now deploy your wrapper and smart contract to a local test environment.

To stand up a local Ethereum and IPFS node, run:

yarn test:env:up

Next, deploy the wrapper and smart contract:

yarn deploy

Run the test and view test results in your output window:

yarn test:e2e