Support vararg files to instrument

[jsdevel]

It would be really nice if istanbul instrument accepted a vararg number of files / directories to instrument as the last argument[s].

[gotwarlost]

How would you specify where the output files are created in this case?

[jsdevel]

@gotwarlost the --output option allows for a file or directory, so I naturally assumed this would work: istanbul instrument --output lib-cov lib server.js.

[gotwarlost]

So in your example, lib-cov will have a server.js in it and a subdirectory called lib? In the one-arg case it is always clear what the root output directory is. Not so in the multi-arg case - it would have to be the common ancestor of all files/ dirs passed in.

[jsdevel]

I can see your point.

A lot of projects have a root file like server.js or app.js. They also have lib. Would there be a better way other than var args?

[gotwarlost]

I do agree with you that having the app.js or server.js outside the only directory you want to instrument requires you to jump thru hoops by passing the top-level dir and a bunch of excludes.

I do like the interface you have proposed - I think calling the output dir lib-cov is confusing. Instead if you said istanbul instrument --output instrumented-app server.js lib the command makes perfect sense.

I need to see if there are any other implications of supporting multiple dirs/ files.