JS technical test

Scope

Consider the following code:

var a = b = 5;
console.log(b);

What will be printed on the console?

Hoisting

Describe what the following will return and why

function bar() {
   console.log(a);
   console.log(foo());
   var a = 1;
   function foo() {
      return 2;
   }
}
bar();

Flow

Describe the predicted output of, and why

console.log("john");
setTimeout(function() {
    console.log("jack");
}, 0);
console.log("jake");

Extend basic prototypes

Write javascript to make the following:

console.log('helloworld'.repeatit(3));

output: helloworldhelloworldhelloworld

Classes

How do you declare a class in Javascript?
How do you extend a class in Javascript?
How do you mixin a class in Javascript?
How do you create a new instance of a class?

Quickfire

Describe the difference between == and ===
Assuming function myfunc() {} describe the difference between myfunc() myfunc.call() and myfunc.apply()
Describe the difference between null and undefined
What is an error-first callback?
How can you avoid callback hells?
How can you listen on port 80 with Node?
What's the event loop?
What's the difference between operational and programmer errors?

Discussion points

AWS/rackspace/similar cloud
NoSQL stores
Docker
Technology you're excited about
Mysql when would you use INNODB vs MYSIAM
Talk about what HTTP methods there are and what they are used for.
Talk about what RESTful means to you
Describe what HATEOAS means to you
What tools can be used to assure consistent style?
Why npm shrinkwrap is useful?

What don't you like about:

JS/angular/backbone/ember
Node.js
Mysql/postgre
NoSQL store
other technology

Git

Assume you have commits pushed to origin:ABCDEF

You discover another developer put a password in C, discuss how you could go about editing that commit
You find it would make more semantic sense to reorder the commits to AEBCF
You find it would make more semantic sense to combine commits A & B Assume have another branch with commits: WXYZ
You want to take commit Y and add it after E

Testing

Describe a test pyramid
How can you implement it when talking about HTTP APIs?
Describe mocking, stubbing
Describe the difference between BDD and TDD
Why would you use BDD/TDD, are they mutually exclusive?

Docker

Describe the difference between RUN, CMD, and ENTRYPOINT
Describe the difference between ADD and COPY
What is a multi-stage build and why would you use one?
Figure how to start up and return a salted hash with the docker image chrisns/docker-devtest

Kubernetes

Your metrics appear to show that when the pod schedudles it bounces queries for a bit, why might this be?

---
kind: Deployment
apiVersion: apps/v1
metadata:
  name: mydeployment
spec:
  replicas: 30
  selector:
    matchLabels:
      name: mydeployment
  template:
    metadata:
      labels:
        name: mydeployment
    spec:
      containers:      
      - image: chrisns/mywonderful-notreal-app
        name: mydeployment
        livenessProbe:
          httpGet:
            path: /health/liveness
            port: http
          initialDelaySeconds: 90
          periodSeconds: 3
          timeoutSeconds: 1

        readinessProbe:
          httpGet:
            path: /health/readiness
            port: http
          initialDelaySeconds: 60
          periodSeconds: 3
          timeoutSeconds: 1

chrisns/techtest.md