Proposal: 3rd party formatters

[Freyert]

The tap-mocha-reporter exposes a more convenient interface for certain use cases than the tap-parser. It would be nice to be able to create 3rd party reporters to use with tap-mocha-reporter.

This is just a cheap trick that I've created to work around my issue, but it would be nice to formalize a system for 3rd party formatters.

Issues

1. Can't load project local node_modules without adding it via NODE_PATH.

[rmg]

Can't load project local node_modules without adding it via NODE_PATH.

This doesn't make sense. Are you using a globally installed tap instead of a local versions (as per devDependencies)? Or perhaps you've done npm link, in which case resolution will be relative to your tap module's location..

[Freyert]

Ah, yes I was using file: in the package.json for the third party module. Let me try differently.

[Freyert]

That's fixed it, thanks @rmg.

[Freyert]

After looking at this a bit more, this seems like the easiest insertion to add this functionality. Editing the error message to include the caveat: "Perhaps you were attempting to load a 3rd party reporter; please ensure it exists in the require path," would improve the quality.

Tests as well :}

[darvin]

bump

[wking]

Passing in a reporter function (as supported by this PR) looks useful to me for folks calling this from JavaScript. Another approach (potentially more useful from the tap CLI) would be loading a 3rd-party package using require(...). I've submitted #48 with an implementation for that. This package could support both approaches, although there will be trivial conflicts between the PRs as we get them landed.