Developing for

Humans

mature

Great programmers are not always

engineers

"Mature" engineering has

many facets

Writing

maintainable

code

Being a

zealous

reviewer

"If a lion could speak, we could not understand him"

Wittgenstein

A lesson from the design team:

Waterbear

Be a

But here are some of mine

your own

Develop

best practices

Caveats:

Programming should be

Hackathons, POCs, throwaway code is

fun

exempt

I am opinionated. Some of my opinions are controversial

use quirks

Never

if(~'human'.indexOf('u')){
  // When is this executed?
}

if(_.includes('human', 'u')){
  // This is a lot clearer
}

function isReadable(){
  return !!this.readable;
}

function isReadable(){
  return Boolean(this.readable);
}

var date = +new Date()

var date = Date.now();

->

->

->

Keystrokes are

cheap

Comprehension is

expensive

No single letter variables

No abbr in function names

Naming is

hard

but

important

var d = 5;
var stateList = ['pending','active'];
var open = true;

var elapsedTimeInDays = 5;
var possibleStates = ['pending','active'];
var isOpen = true;

->

Function names should imply a return type

function pending(){}
function orgs(){}
function states(){}
function calculatePercentage(){}

function isPending(){}
function hasOrganizations(){}
function getStates(){}
function getPercentage(){}

->

Variable names should be descriptive

Fail

function getSomething(){
  if(condition) {
    something();
    _.each(things, function(thing)
      if(thing.widget){
        if(somethingElse(thing.widget)){
          doThing(thing);
        }
      }
    });
    return true;
  }
  return false;
}

function getSomething(){
  if(!condition){
    return false;
  }
  // Long function body
}

Avoid many nested conditions by returning as quickly as possible

fast

->

Semantic is

var result = [];
_.each(rums, function(rum){
  if(rum.year < 1918){
    result.push(rum);
  }
});

_.filter(rums, function(rum){
  return rum.year < 1918;
});

_.each(rums, function(rum){
  if(rum.year < 1918){
    rum.isDelicious = true;
  }
});

_.map(rums, function(rum){
  rum.isDelicious = Boolean(rum.year < 1918);
  return rum;
});

Use core concepts to communicate intent

scannable

return types

function getNumberOfEmployees(state){
  var employeeStateMap = {
    'active': 5,
    'pending': 10
  }
  return employeeStateMap[state];
}

function getNumberOfEmployees(state){
  var employeeStateMap = {
    'active': 5,
    'pending': 10
  }
  return employeeStateMap[state] || 0;
}

Functions should always return the same type

Consistent

Nested Ternary Expressions

Else is

function isProper(sausage){
  if(sausage.isMadeOfChicken()){
     return false;
  } else {
    return true;
  }
}

function isProper(sausage){
  if(sausage.isMadeOfChicken()){
     return false;
  }
  return true;
}

redundant

If you need an else in your function then your function does too much.

Keep flow control at the

highest level

possible

function submitForm(){
  var data = this.getFormData();
  validateForm(data);
}

function validateForm(data){
  if(isValid(data)){
    augmentData(data);
  }
}

function augmentData(data){
  data.something = 123;
  makeXHRCall(data);
}

function submitForm(){
  var data = this.getFormData();
  if(!isValid(formData)){
    return;
  }
  var augmentedData = augmentData(data);
  makeXHRCall(data);
}

function augmentData(data){
  data.something = 123;
  return;
}

->