Oakley Hall ohall

A few questions for quickly assessing candidate's Node.js skill level

Write a function that simulates an asynchronous I/O function call. The function should be called ping. It should accept one argument called delay that will determine how many seconds before the function will call back with a response (pong). If no argument is provided, it should call back immediately. If the argument is greater than 3, it should call back with an error.

function ping(delay, callback) {
 // if delay is not provided, it should default to 0
 if (typeof delay === 'function') {
   callback = delay;
   delay = 0;

System Design Cheatsheet

Picking the right architecture = Picking the right battles + Managing trade-offs

Basic Steps

Clarify and agree on the scope of the system

User cases (description of sequences of events that, taken together, lead to a system doing something useful)
- Who is going to use it?
- How are they going to use it?

	; function findItem() { ;
	; var item ;
	; while(item_not_found) { ;
	// search
	; } ;
	; return item ;
	; } ;

	; var item = findItem() ;

	#!/usr/bin/env bash

	#place the git repo directories here, space delimited
	PROJECTS=(~/Projects/foo ~/Projects/bar)

	DOW=$(date +%w)
	if [[ $DOW -eq 1 ]]; then #Monday
	SINCE=4.days
	else
	SINCE=2.days

	<IfModule mod_rewrite.c>
	RewriteEngine On
	RewriteBase /
	RewriteRule ^index\.html$ - [L]
	RewriteCond %{REQUEST_FILENAME} !-f
	RewriteCond %{REQUEST_FILENAME} !-d
	RewriteRule . /index.html [L]
	</IfModule>

	function *foo(x) {
	var y = 2 * (yield (x + 1));
	var z = yield (y / 3);
	return (x + y + z);
	}

	//this "instantiates" (not sure if this is correct??) the generator
	//and returns an object with a `next` method
	var it = foo( 5 );

	# Plain Ol' Node
	node --max-old-space-size=1024 app.js # increase to 1gb
	node --max-old-space-size=2048 app.js # increase to 2gb
	node --max-old-space-size=3072 app.js # increase to 3gb
	node --max-old-space-size=4096 app.js # increase to 4gb
	node --max-old-space-size=5120 app.js # increase to 5gb
	node --max-old-space-size=6144 app.js # increase to 6gb

	# For pm2
	pm2 start app.js --node-args="--max-old-space-size=1024" # increase to 1gb

	#!/bin/bash

	STORY_KEY=$(git symbolic-ref --short HEAD \| grep -Eo '^[a-zA-Z0-9]{3,}[-_][0-9]{1,5}' \| awk '{sub(/_/, "-"); print toupper($0)}')

	if [ -n "$STORY_KEY" ]; then
	sed -i.bak -e "1s/^/[$STORY_KEY] /" $1
	fi

	// thanks to @raganwald
	function spread(fn) {
	return Function.apply.bind( fn, null );
	}

	function foo(x,y,z) {
	console.log(x,y,z);
	}

	function bar(fn) {