Decora.js

Get Started

Enable experimentalDecorators

{
  "compilerOptions": {
    ...
    "experimentalDecorators": true,
  }
}

usages & specs

import decora from ".";
import { it, expect, spyOn, mock } from "bun:test";

function peekFn<A extends any[], R>(fn: (...args: A) => R) {
  return (...args: A) => {
    const ret = fn(...args);

    Promise.resolve(ret).then((ret) =>
      console.log(`${JSON.stringify(args)} => ${ret}`),
    );
    return ret;
  };
}

class Test {
  @decora(peekFn)
  add(a: number, b: number) {
    return a + b;
  }
  @decora(peekFn)
  async addAsync(a: number, b: number) {
    return a + b;
  }
  @decora(peekFn)
  static staticAdd(a: number, b: number) {
    return a + b;
  }
  @decora(peekFn)
  static async staticAddAsync(a: number, b: number) {
    return a + b;
  }
}

it("Decora with peek function", async () => {
  spyOn(console, "log");
  expect(new Test().add(1, 2)).toBe(3);
  expect(await new Test().addAsync(2, 3)).toBe(5);
  expect(Test.staticAdd(3, 4)).toBe(7);
  expect(await Test.staticAddAsync(4, 5)).toBe(9);
  expect(console.log).toHaveBeenCalledWith("[1,2] => 3");
  expect(console.log).toHaveBeenCalledWith("[2,3] => 5");
  expect(console.log).toHaveBeenCalledWith("[3,4] => 7");
  expect(console.log).toHaveBeenCalledWith("[4,5] => 9");
});