Grunt concat not working during watch task - gruntjs

Question

If I run 'grunt concat' it compiles my JS files as per the Grunt file (line 82). However, it doesn't concatenate when I'm doing 'grunt watch' (line 107).
From what I can see, my file is ok but I'm fairly new to grunt so would love to see if you guys can see an issue.
Here is my full Grunt file...
// All scripts to be included in project go here
var _SCRIPTS = [
'js/prefixfree.js',
'js/jquery-1-10-2.js',
'js/ie-detect.js',
'js/application.js'
];
var _PORT = 7777;
module.exports = function(grunt) {
// load all grunt tasks
require('matchdep').filterDev('grunt-*').forEach(grunt.loadNpmTasks);
// Project configuration.
grunt.initConfig({
pkg: grunt.file.readJSON('package.json'),
connect: {
server: {
options: {
port: _PORT,
base: 'prototype'
}
}
},
htmlvalidation: {
options: {
},
files: {
src: ['prototype/*.php']
},
},
jshint: {
beforeconcat: _SCRIPTS,
afterconcat: ['js/main.js']
},
csslint: {
check: {
src: ['css/*.css']
},
strict: {
options: {
import: 2
},
src: ['css/*.css']
},
lax: {
options: {
import: false
},
src: ['css/*.css']
}
},
compass: {
dev: {
options: {
config: 'config.rb',
force: false
}
}
},
uglify: {
options: {
banner: '/*! <%= pkg.name %> <%= grunt.template.today("dd-mm-yyyy") %> */\n'
},
dist: {
files: {
'js/main.js': ['js/main.js']
}
}
},
concat: {
options: {
stripBanners: true,
banner: '/*! <%= pkg.name %> - v<%= pkg.version %> - ' +
'<%= grunt.template.today("yyyy-mm-dd") %> */',
},
dist: {
src: _SCRIPTS,
dest: 'js/main.js',
nonull: true
},
},
cssmin: {
add_banner: {
options: {
banner: '/* <%= pkg.name %> - v<%= pkg.version %> - ' +
'<%= grunt.template.today("yyyy-mm-dd") %> */',
},
files: {
'css/style.css': ['css/style.css']
}
}
},
watch: {
concat: {
files: ['js/**/*.js', '!js/main.js'],
tasks: 'concat',
options: {
spawn: false,
},
},
sass: {
files: ['sass/**/*.scss'],
tasks: ['compass:dev'],
options: {
spawn: false,
},
},
/* watch and see if our javascript files change, or new packages are installed */
/* watch our files for change, reload */
livereload: {
files: ['*.html', 'css/*.css', 'img/*', 'js/*.js'],
options: {
livereload: true
}
},
}
});
// Default task (Watch)
grunt.registerTask('default', ['watch']);
// grunt.registerTask('default', [ 'preprocess:dev', 'watch']);
// Watch with localhost (For Static Templates)
grunt.registerTask('watch_with_server', [ 'connect:server', 'watch']);
// TESTING
// Run all tests
grunt.registerTask('allTests', [ 'jshint:beforeconcat', 'concat', 'jshint:afterconcat', 'cssLint', 'htmlvalidation']);
// JS Testing
grunt.registerTask('jsHint', ['jshint:beforeconcat', 'concat', 'jshint:afterconcat']);
// CSS Testing csslint
grunt.registerTask('cssLint', ['csslint:check']);
grunt.registerTask('cssLintLax', ['csslint:lax']);
grunt.registerTask('cssLintStrict', ['csslint:strict']);
// HTML Vaidation
grunt.registerTask('htmlTest', [ 'htmlvalidation']);
grunt.registerTask('printenv', function () { console.log(process.env); });
// Concat and uglify js and minify css for release
grunt.registerTask('release', [ 'concat:dist', 'uglify', 'cssmin']);
};
Many thanks

Answer 1

I managed to get it working by moving 'livereload' above 'concat' in the watch task. No idea why this would make a difference but it's working!
If anyone has any insight on why this would affect it I'd love to know.

Answer 2

add this and see:
livereload: {
files: ['*.html', 'css/*.css', 'img/*', 'js/*.js'],
options: {
livereload: true
}
},
options: {
livereload: true
},
files: '<%= options.watch.files %>',//might have to change this line
tasks: ['default', 'notify:watch']