CodeCity - Visualize Your JavaScript As A City

Written by Ian Elliot

Monday, 29 May 2017

If you haven't encountered the idea of CodeCity before then this is going to be fun. Even if you have it is worth checking out what some familiar JavaScript code libraries look like as cities.

The CodeCity software visualization metaphor was originally proposed by Wettel and Lanza in 2011 to visualize object-oriented code. JSCity is an implementation of these ideas in JavaScript for JavaScript by three researchers Marcos Viana, Andre Hora and Marco Tulio Valente based in Brazil.

In the original CodeCity classes are represented as buildings, but this has had to be adapted because JavaScript is not a simple, class-based, language. The obvious thing to do is to replace class by functions.

JSCity represents a JavaScript program as a city; folders are districts and files are sub-districts; the buildings are functions; inner functions are represented as buildings on the top of their enclosing function/building. The Number Of Lines of source Code (LOC) represents the height of the buildings/functions; the Number Of Variables (NOV) in a function correlates to the building’s base size.

jscity1

So when you view the cityscape, big buildings correspond to big functions.

The program was implemented in JavaScript using the Esprima framework to generate an abstract syntax tree for the code and ThreeJS for the 3D graphics. Once the city is rendered you can move around, change the camera angle and zoom in to view it better. The software is available on GitHub for you to try out.

The researchers also analyzed 40 well-known JavaScript code bases and they present three as being particularly interesting - AngularJS core functions, Bower and jQuery - see if you can guess which is which:

CITY A

cityA

CITY B

cityB

CITY C

cityc

I have to admit that I recognized my favorite JavaScript library almost at once! The identity of each city can be found at the very very end of this news item - scroll down.

More Information

CodeCity for (and by) JavaScript

JSCITY On GitHub

Does Python Smell Like Java?

On the Unhappiness of Software Developers

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