promall/test.js

Make creating and handling promises easy

'use strict'

const p = require('./promall');

function out(msg, label){
  if(msg !== null && msg !== undefined){
    if(label && label.length){
      label = `"${label}" = `;
    } else {
      label = '';
    }
    if(msg instanceof Object){
       if(label === ''){
        label = ' - ';
      }
      console.log(label + JSON.stringify(msg));
    } else {
      console.log(label + msg);
    }
  }
}

async function test(){
  var f1 = function(x, y, z) {
    out(x, 'x');
    out(y, 'y');
    out(z, 'z');
    return x + y + z
  };
  var p1 = p(f1, 1,2,3);
  out(p1, 'p1')
  await p1.then((res) => {
    out(res, 'p1.res')
  })

  var a = 1;
  var b = 2;
  var p2 = p.wrap((x, y) => { return x + y; });
  await p2(a, b).then((res) => out(res, 'p2'));
  await p2(5, 2).then(res => out(res, 'p3'));

  var pp = function(k, m) {
    return new Promise((resolve, reject) => {
      resolve(k + m);
    });
  };
  await p(pp, 1, 2).then((res) => out(res, 'p-pp'));
  await p.wrap(pp)(3, 4).then((res) => out(res, 'pf-pp'));

  await p(() => { throw "THIS IS AN ERROR"})
    .then((res) => out(res, 'pe1'))
    .catch((err) => out(err, 'pe-err1'));

  p.doNotWrapErrors();

  try{
    p.await(p(() => { throw "THIS IS ANOTHER ERROR"})
      .then((res) => out(res, 'pe2'))
      .catch((err) => out(err, 'pe-err2')));
  } catch(error){
    console.log("Caught the unwrapped error");
    console.error(error);
  }

  var k1 = (a) => { console.log(a); return a + 1; }
  var k2 = (a) => { console.log(a); return a + 10; }
  var k3 = (a) => { console.log(a); return a + 100; }
  var k4 = (a) => { console.log(a); return a + 1000; }

  var chainOfPromiseReturningFunctions = [
    p.wrap(k1), p.wrap(k2), p.wrap(k3), p.wrap(k4) ]

  var chainResult = await p.executeChain(chainOfPromiseReturningFunctions, 0);

  console.log(`Chain result: ${chainResult}`);

  return 'Passed';
}

p(test).then(result => out("Done: " + result));