Why isn't grunt reloading my updated less files? - less

Question

I'm trying to get Grunt to process my less files every time I make a change to one of the files.
I have a 'watch' task working, and it says it is processing files when I make a change, and it outputs the correct files which change, so my watch is working, but the changes I make are not being made on the css file.
My file structure is like this
-styles
globals.less
components.less
-menu
menu.less
-header
header.less
The components.less file is a group of less mixins to grab the other .less files like #import "menu/menu.less";
In my grunt file, I have
less: {
development: {
options: {
paths: ['./app/vendor/modern-touch-less','./app/styles']
},
files: {
'./app/styles/modern-touch.css':'./app/vendor/modern-touch-less/style.less',
'./app/styles/components.css':'./app/styles/components.less'
}
}
},
watch: {
js: {
files: ['/scripts/{,*/}*.js','/styles/{,*/}*.less'],
tasks: ['newer:jshint:all, less'],
options: {
livereload: true
}
},
styles: {
files: ['./styles/{,*/}*.*','./vendor/{,*/}*.less'],
tasks: ['less','newer:copy:styles', 'autoprefixer'],
options: {
nospawn: true,
livereload: true
}
},
}
When I first start the app, the less files are built into the correct components.css file, but after changing a file, the components.css file is not updated.
Grunt is started with
grunt.task.run([
'clean:server',
'bower-install',
'concurrent:server',
'less',
'autoprefixer',
'connect:livereload',
'watch',
'karma'
]);

Answer 1

Perhaps you can try simplifying your configuration, by splitting tasks out to run on the appropriate set of files.
watch: {
js: {
files: ['/scripts/{,*/}*.js'],
tasks: ['newer:jshint:all'],
options: {
livereload: true
}
},
styles: {
files: ['./styles/{,*/}*.*','./vendor/{,*/}*.less'],
tasks: ['less','newer:copy:styles', 'autoprefixer'],
options: {
nospawn: true,
livereload: true
}
},
}
In your original watch config, the watch.js.tasks array was ['newer:jshint:all, less'], which looks like a typo, should be ['newer:jshint:all', 'less']. This may fix the problem too, but I would consider just running tasks on the files that they are affected by.