Implements Tests and rewrite the codebase using ES6 (related to the issues #33 #3)

[thiamsantos]

• Write tests using Mocha, Karma, Assert and PhantomJS. I was able to reach code coverage of 100% 🎉, so will be a good thing integrate the project with coveralls.

• Rewrite the codebase using ES6.
• Add a build step for bundling three different versions of the module using rollup. A CommonJS version is expose through the property main on the package.json, an ES6 version is exposed through the property module on the package.json and also a umd version will be available at unpkg after this PR was accepted and ublished to npm.
• Add node gitignore.
• Add a visual test example to see waterfall in action. Was used the same example available at the project page.
• Add git hooks with a help from husky to:
  1. Prevent commits that doesn't follow the code style.
  2. Always build the files before commiting.
  3. Prevent commits that have bronken tests.
• Add a npm script to run the build, test and the visual at watch mode. You can just type npm start.

[raphamorim]

Ref #34 #33
Nice @thiamsantos, I'll review it tonight 👍

[thiamsantos]

Any thoughts @raphamorim?

[raphamorim]

I'm start reviewing it now, sorry by delay

I have some questions to proceed:

• Why to use ES6? (Only to know)
• Why it generate two files: cjs and umd version? Why it? How bower will understand it?
• Can you add Nodejs 7 in travis.yml?
• If you're already using ES6 notation, can you test import cases too?

Also nice job testing UI behavior and remaining waterfall size after transpile it (I believe Rollup was a good choice)

[thiamsantos]

Thanks for taking time to review it @raphamorim!!

Why to use ES6?

ES6 provide some improvements on the syntax. Since a refactor was needed to implement the unit tests, why not use ES6 in that refactor?

Why it generate two files: cjs and umd version? Why it? How bower will understand it?

The cjs version is handled by npm when you type require('waterfall.js'). And the UMD version is used when you just embed the script on the browser (maybe using unpkg). For bower is needed to specify the main property on bower.json pointing to the UMD version (I forgot to do that 😁).

Can you add Nodejs 7 in travis.yml?

Sure. I will add the latest stable Node.js release to travis.yml.

If you're already using ES6 notation, can you test import cases too?

The import statement was not working just because the main property on package.json was pointing to a file that did not exist.

[thiamsantos]

On second thought the cjs version is actually not necessary, because the umd version is 'universal' and works well with CommonJS modules. So I can remove the cjs a leave just the umd version and the ES6 version. What do you think @raphamorim? I can commit that?

[thiamsantos]

The travis test on node v7.5.0 failed. It seems to be a problem related to yarn not building karma-phantomjs-launcher.

[ghost]

Seu código é muito bonito, @thiamsantos 😄 👍

[thiamsantos]

Any thoughts @raphamorim?