Awesome
gulp-conflict 
Check if files in stream conflict with those in target dir, with option to use new, keep old, show diff, etc.
Primary objective
Used before any gulp.dest step when using slush as a Yeoman replacement.
Installation
For global use with slush
Install gulp-conflict as a dependency:
npm install --save gulp-conflict
For local use with gulp
Install gulp-conflict as a development dependency:
npm install --save-dev gulp-conflict
Usage
In your slushfile.js:
var conflict = require("gulp-conflict");
gulp.src(__dirname + '/templates/**')
.pipe(conflict('./'))
.pipe(gulp.dest('./'));
In your gulpfile.js:
var install = require("gulp-conflict");
gulp.src(['./files/*.js'])
.pipe(conflict('./dir'))
.pipe(gulp.dest('./dir'));
API
conflict(dest, options)
dest
Type: String, required
Specify destination directory to compare files in, should be the same as destination directory for gulp.dest.
options
Type: Object, optional
options.cwd - specify another working directory than process.cwd()
options.defaultChoice - default choice on conflicts e.g. 'y' (replace, default), 'n' (skip), 'd' (diff)