There is a problem which can result in nothing being added to the output html file.
I dug around a bit and the solution seems to be to include an option to specify the location of the javascript files that are to be included.
The current code assumes that the js/css files are located relative to the input file but that doesn't work once you start to do thing like build it with jade e.g.
gulp.src('./src/jade/*.jade')
.pipe(jade())
.pipe(includeSource())
.pipe(gulp.dest('./app'));
It is looking in ./src/jade for my scripts and I need a way to tell it to look in ./app or maybe ./src/js