difference between d3.v3.js and entire D3 repository

Question

For d3, or any javascript package in general, what is the difference between the js file which has the entire source code(say, d3.v3.js) and the github repo for it(in the case of d3, it is https://github.com/mbostock/d3).

What does the github repo contain that the entire source code does not?

I read on Scott Murray's tutorials that the D3 repository contains "all of the component source code". Can someone explain what's meant by 'component'?

Answer 1

Zeke Sonxx's answer is excellent. I'll just add that in the case of Javascript, because the source code can be run directly, there might be less need for a github repo. But even in the simplest cases, you get to add additional files when needed, keep track of problems and plans in the github issue system, etc. Example: The gexf-parser repo only has one main source file, src/parser.js, but there is a collection of files for testing as well, and a few other useful files. Javascript can also be "compiled", but it's not compilation in the sense of some languages (C, Java, Clojure, etc.). The application distributed will often be built from many different source files in the repo.

Answer 2

it is the same as with any project in development environment and deployment environment, so in github that's a development environment for d3.js d3.v3.js is the compiled library that you need to use in your product.

Answer 3

Let's look at the Whatever library. It does whatever. The repo for it is located at https://github.com/someone/whatever.js (this is not a real repo).

The repo itself usually contains a variety of info, including documentation, style guides, and code organization. Whatever.js is actually made up of three files: lib/whatever.js, lib/whatever-tools.js, and lib/whatever-xml.js. These get concatenated for actual use, but for development of whatever.js itself it's easier to work with separate files.

Having to deal with just commits all on a single file is absolutely horrible. Pull requests would be even worse.

The distributed version, aka whatever.js and whatever.min.js, is a version of the repo code after it's been dealt with however it needs to be. In the case of most libraries the files just get concatenated, but for some libraries fancy things happen. The .min.js version is the normal file, but after being run through a minification tool, these days usually UglifyJS2.

Some libraries will not even have all of the code in the main generated file, usually due to usage reasons. For example, Angular.js doesn't have the ng-route module in angular(.min).js, you need to include angular-route(.min).js too. This is for sanity reasons, because quite a lot of Angular uses don't need or want the routing system, and it's a fairly big addon.