Add accessibility audit helper

[kevinsawicki]

Adds support for running an accessibility audit using https://github.com/GoogleChrome/accessibility-developer-tools

New API is app.client.auditAccessibility() and it resolves to an audit object with details about any failures.

/cc @jlord @zeke

[zeke]

what are minHeight and minWidth needed for?

[kevinsawicki]

I copied another fixtures folder that had these set, they aren't explicitly needed by any of the new accessibility specs.

[zeke]

I wonder if you could just npm install accessibility-developer-tools instead of manually copying the bundled source...

[kevinsawicki]

I wonder if you could just npm install accessibility-developer-tools instead of manually copying the bundled source...

You can't, it isn't require-able.

[zeke]

it isn't require-able.

I took at stab at making it require-able last night. Got close but still a few hiccups.

Obviously this is just a nice-to-have. In the meantime, I say

[kevinsawicki]

I took at stab at making it require-able last night. Got close but still a few hiccups.

Yeah, it would be great to switch it to an npm dependency eventually if upstream addresses this issue.

[dylanb]

If you want an accessibility module that supports require (UMD) and has a bigger and more robust set of rules, take a look at axe-core https://www.npmjs.com/package/axe-core