aa

test.js

class Test {
  constructor() {}
  getInfo() {
    return {
      id: 'test',
      name: 'Test',
      blocks: [
        {
          opcode: 'hello',
          blockType: Scratch.BlockType.COMMAND,
          text: '💩'
        }
      ]
    }
  }
  hello() {
    alert('hello')
  }
}
Scratch.extensions.register(new Test());