gulp-insert
String manipulation library for gulp
Usage
npm install gulp-insert
var insert = require('gulp-insert'); 
Append
Appends a string onto the contents.
.pipe(insert.append('world')); // Appends 'world' to the contents of every file 
Prepend
Prepends a string onto the contents.
.pipe(insert.prepend('Hello')); // Prepends 'Hello' to the contents of every file 
Wrap
Wraps the contents with two strings.
.pipe(insert.wrap('Hello', 'World')); // prepends 'hello' and appends 'world' to the contents 
Transform
Calls a function with the contents of the file.
.pipe(insert.transform(function(contents, file) {
  return contents.toUpperCase();
})); 
Transform has access to the underlying vinyl file. The following code adds a '//' comment with the full file name before the actual content.
.pipe(insert.transform(function(contents, file) {
	var comment = '// local file: ' + file.path + '\n';
	return comment + contents;
})); 
See https://github.com/wearefractal/vinyl for docmentation on the 'file' parameter.
 JarCasting
 JarCasting