Grunt: cssmin not working - gruntjs

Question

I am trying to minify CSS using Grunt cssmin plugin. Below is my code:
// Minify CSS
cssmin: {
build: {
options: {
banner: '/* Minified CSS */'
},
files: {
'htt/css/style.min.css' : ['wp/css/**/*.css']
}
}
},
when i run "grunt cssmin" it gives error of "Unexpected identifier".

Answer 1

You where missing a comma after the js object in the watch task, for future you can edit your answer to provide more information instead of posting it as an answer :)
// Watch Tasks
watch: {
js: {
files: ['wp/js/*.js'],
tasks: ['uglify:dev']
}, <------- Missing comma
css: {
files: ['wp/css/*.css'],
tasks: ['']
}
}
});

Answer 2

#mike
`module.exports = function (grunt) {
// Configure Tasks
grunt.initConfig ({
pkg: grunt.file.readJSON ('package.json'),
// Uglify JS
uglify: {
build: {
src: 'wp/js/*.js',
dest: 'htt/js/script.min.js'
},
dev: {
options: {
beautify: true,
mangel: false,
compress: false,
preserveComments: 'all'
},
src: 'wp/js/*.js',
dest: 'htt/js/script.min.js'
}
},
// Concatenating files
concat: {
build: {
src: ['wp/css/*.css'],
dest: 'htt/css/style.css'
}
},
// Minify CSS
cssmin: {
build: {
//options: {
// banner: '/* Minified CSS */'
//},
files: {
'htt/css/style.min.css' : ['wp/css/**/*.css']
}
}
},
// Watch Tasks
watch: {
js: {
files: ['wp/js/*.js'],
tasks: ['uglify:dev']
}
css: {
files: ['wp/css/*.css'],
tasks: ['']
}
}
});
// Load the Plugins
grunt.loadNpmTasks ('grunt-contrib-uglify');
grunt.loadNpmTasks ('grunt-contrib-watch');
grunt.loadNpmTasks ('grunt-contrib-concat');
grunt.loadNpmTasks ('grunt-contrib-cssmin');
// Register Tasks
grunt.registerTask ('default', ['uglify:dev']);
grunt.registerTask ('build', ['uglify:build', 'cssmin']);
};`
Above is the whole gruntfile.js file