NEAR AssemblyScript Project Set Up

Overview

• Prerequisites
• Establishing Vocabulary
• Initializing Project Environment

Prerequisites

• Install NodeJS
• Install Yarn

Establishing Vocabulary

• TypeScript
  • strongly typed programming language that builds on JavaScript, giving you better tooling at any scale.
• WebAssembly
  • low-level language with a compact binary format that runs with nearly-native-performance in the browser.
• AssemblyScript
  • strict variant of TypeScript specially created for WebAssembly.

Initializing Project Environment

Npm initialization

• Execute the command below to create a new directory as workspace of project.
  • mkdir -p ~/dev/my-first-near-project
• Execute the command below to change directory to the newly created my-first-near-project directory
  • cd ~/dev/my-first-near-project
• Execute the command below to initialize a new package.json to configure your npm packages.
  • npm init

Configuration Initialization

• Execute the command below to create a new directory named assembly
  • mkdir assembly
• Execute the command below to populate the project directory with an AssemblyScript config file.
  • echo "{ \"extends\" : \"near-sdk-as/asconfig.json\" }" > ./asconfig.json
• Execute the command below to populate the project directory with an TypeScript config file.
  • echo "{ \"extends\" : \"assemblyscript/std/assembly.json\" }" > ./tsconfig.json
• Execute the command below to populate the assembly directory with a TypeScript index file
  • echo "export function helloWorld(): string { return \"hello world\"; }" > ./assembly/index.ts
    • Upon execution, this file will return hello world as a string

Yarn Initialization

• Execute the command below to add the yarn dependency for near-sdk
  • yarn add -O near-sdk-as
• Modify the package.json file by replacing dependencies block with the devDependencies block below

{
    // ...
    "devDependencies":{
        "near-sdk-as": "^3.0.0"
    }
    // ...
}

• Modify the package.json to include a scripts.build key with a value of asb
  • "build":"asb"

• Execute the command below to build the project in AssemblyScript
  • yarn asb
    • Upon execution, a new directory named build should generate with contents reflecting the compiled AssemblyScript bytecode with extension .wasm
• Execute the command below to build the project in AssemblyScript in human-readable code
  • yarn asb --wat
    • Upon execution, a new directory named build should generate with contents reflecting the compiled AssemblyScript human-readable code with extension .wat

Test Initialization

• Execute the command below to initialize tests
  • yarn asp --init
    • Upon execution, a new directory named ./assembly/__tests__/ should generate with boilerplate testing content
      • as-pect.d.ts
      • example.spec.ts
• Modify the file example.spec.ts to reflect the code below

import {helloWorld} from '..';

describe("example", ()=>{
    it("should return 'hello world'", ()=> {
        expect(helloWorld()).toStrictEqual("hello world");
    })
})

• Modify the file as-pect.config.js to reflect the code below

module.exports = require("near-sdk-as/imports")

• Execute the command below to run tests.
  • yarn asp
    • ensure the test passes