AWS:

Currently we spent $80 on AWS

Node.js:

Bluebird revisit:

• If you pass a promise object to the resolve function, the created promise will follow the state of that promise.

  const Promise = require('bluebird');
  const aPromise = new Promise(function(resolve, reject) {
    // vvv if you wanna resolve
    // resolve('hello');
    reject('world');
  });
  const bPromise = Promise.resolve(aPromise).catch(function(err){
    console.log('So its OOOOO ' + err + ' again?');
  });
    
  // Then bPromise should inherit aPromise's state (i.e. rejected)
  // 'So its OOOOO world again?' should be printed
  

• Actually, we may make bPromise handle aPromise’s rejection in then like

  const bPromise = Promise.resolve(aPromise).then(function(resV){
    console.log('This cant happen', resV);
  }, function(rejV){ 
    console.log('Since its ' + rejV + ' ,you got rejected');
  }).catch(function(err){
    console.log('For any unexpected err lile', err);
  });
  
  // Should print 'Since its world ,you got rejected'
  

• Filtered catch looks more reliable …
• Perhaps the previous one’s rejection handling function in then is a long-term of catch(function(someErr){ .. })? We got supported here
• This is how you chaining Promises’ val in if else branch

  If you are wondering why npm install -g SOMEPACKAGE doesnt work on OSX, this might work

  What is V8 and how does it work?

• Javascript is a Prototype-inheritance lang
• The most intiguing thing is what happens once the underlying instance has only, say 518 MB, to run javascript code in Node.js – GC by V8 engine just couldn’t help but rest!

  Go back to check event loop

  Why do let and var behave differently? This is exactly what has confused me for a while …