add doesMQMatch() fn with unit test coverage

[tilomitra]

This pull request adds the doesMQMatch() function which adds the ability to test a media query against an object. All the media query features that are part of the spec are supported.

Some examples:

doesMQMatch('screen and (min-width: 767px) and (max-width: 979px)', {type: 'screen', width: 800}) // returns true
doesMQMatch('screen and (min-width: 767px) and (max-width: 979px)', {type: 'screen', width: 980}) // returns false
doesMQMatch('screen and (min-width: 767px), screen and (color)', {type: 'screen', color: 1}) // returns true
doesMQMatch('not screen and (color)', {type: 'screen', color: 1}); //returns false

TODO

• Add support for not operator.
• Possible code cleanup (as per PR discussion)
• Improve unit tests and get to 100% coverage.

I added a substantial suite of unit tests to make sure this works properly. You can check that out for some more examples. Just run npm test from the root directory. I'm interested in getting some feedback on the general logic while I finish the remaining tasks. Is there a simpler way to do what I'm doing in the doesMQMatch() function?

Thanks!

[tilomitra]

This is just here because of merge conflicts when I merged your latest changes off master into my working branch.

[ericf]

@tilomitra This is looking create and this package is going to be very useful :)

I opened tilomitra#1 which you can cleanly merge into your branch here.

I like the idea of adding tests. With my implementation of match() some tests don't pass, but that brings up some good talking points that I'll add line comments for. For the test code, can you do the following as a general practice:

• Add 'use strict'; to the file
• Add the Yahoo copyright banner
• Hard break at 80 chars, and follow the coding conventions I used in index.js 😄
• Use BDD-ish expect assertions, like express-state

Some of the tests repeat themselves and aren't very well isolated, e.g. the unit conversion tests also include a boolean (color) expression in the media queries. I think the tests could be refactored to build upon themselves instead of repeat themselves.

I think since you did all these already, we might as well add coverage and get that to 100% for this project. You can look at how express-state is setup for doing this in its package.json "scripts". Also checkout the .gitignore and .npmignore files for keeping test results out of Git and tests out of the npm package.

[tilomitra]

@ericf Thanks for the feedback, I'll get on that.

[ericf]

Sweet! Thanks for getting this up to 100% coverage!