GRUNT: Concatenated CSS files not reflecting in index.html page - css

Question

I have setup grunt task to concatenate the CSS files into a combined.css file and it successfully concatenates the CSS files.
grunt.initConfig({
concat: {
options: {
separator: '\n\n\n',
base: "../../../",
},
css: {
src: [ '../../my/demo/v1.0/1.css',
'../../my/demo/v1.0/2css',
'../../my/demo/v1.0/3.css',
],
dest: '../../my/demo/v1.0/combined123.css',
},
});
grunt.loadNpmTasks('grunt-concat-css');
grunt.registerTask('default', ['concat']);
However, I am not able to figure out how should I replace 1.css, 2.css and 3.css in the index.html with the combined123.css file using Grunt.
When manually trying to replacing these css files with the css files in index.html, running the grunt command reverts back the changes made to index.html. When I do the View Source Code for the page in browser, it shows the multiple css files instead of the latest concatenated combined123.css file.
How can I replace these css files with the combined123.css file in the tag of index.html, using the Grunt task.
This is the Gruntfile.js
grunt.initConfig({
root: root,
//concat:css task implemented here as mentioned in above code snippet
connect: {
server: {
options: {
port: grunt.option('port') || 9090,
keepalive: false,
base: "../../../"
}
}
},
open: {
all: {
path: 'http://localhost:<%= connect.server.options.port%>/my/demo/v1.0/dest/index.html'
}
},
watch: {
html: {
files: ['views/*.html', 'index_temp.html'],
tasks: ['mergeFiles']
},
livereload: {
files: ['dest/index.html'],
options: { livereload: true }
}
},
htmlbuild: {
dist: {
src: 'index_temp.html',
dest: '.tmp/',
options: {
beautify: true,
relative: true,
sections: {
headers: 'views/abc.html',
input: 'views/def.html',
}
}
}
},
replace: {
example: {
src: ['.tmp/index_temp.html'],
dest: 'dest/index.html',
replacements: [ {
from: /^\s*\n/gm,
to: ''
},
{
from: /\s+$/,
to: ''
}],
}
});
require('matchdep').filterDev('grunt-*').forEach(grunt.loadNpmTasks);
grunt.loadNpmTasks('grunt-contrib-concat');
grunt.loadNpmTasks('grunt-concat-css');
grunt.registerTask('server', ['mergeFiles', 'open' ,'connect', 'watch' ]);
grunt.registerTask('default', ['mergeFiles', 'open' ,'connect', 'watch', 'concat']);
grunt.registerTask('mergeFiles', ["htmlbuild:dist", "replace:example"]);
Any help would be much appreciated.