Can't get Sass Source Maps working with grunt-autoprefixer - sass

Question

I'm using Grunt 0.4.5 with these dependencies in my project:
"grunt": "~0.4.5",
"grunt-contrib-concat": "~0.5.0",
"grunt-contrib-uglify": "~0.6.0",
"grunt-contrib-watch": "~0.6.1",
"grunt-contrib-sass": "~0.8.1"
I've just noticed that grunt-autoprefixer didn't get added to my package.json file. Is that because it doesn't have the grunt-contrib prefix? Anyway, Source Maps work for me when I remove autoprefixer from my watch task, but as soon as I add it in again the comment at the very end of the compiled css file gets removed.
This is my autoprefixer config:
autoprefixer: {
options: {
browsers: ['last 2 version', 'ie 8', 'ie 9']
},
single_file: {
options: {
// Target-specific options go here.
},
src: 'library/css/style.css',
dest: 'library/css/style.css'
},
sourcemap: {
options: {
map: true
}
},
},
My Sass config looks like this:
sass: {
dist: {
options: {
style: 'expanded',
debugInfo: true,
sourcemap: true
},
files: {
'library/css/style.css': 'library/scss/style.scss'
}
}
},
and here's my watch task:
watch: {
options: {
livereload: true,
},
scripts: {
files: ['library/js/*.js'],
tasks: ['concat', 'uglify'],
options: {
spawn: false,
},
},
css: {
files: ['library/scss/*.scss'],
tasks: ['sass', 'autoprefixer'],
sourceComments: 'normal',
options: {
spawn: false,
}
},
page: {
files: ['*.php', '*.html']
}
}
I don't get why autoprefixer has to interfere with the source map at all to be honest, I tried using false instead of true, specifying the sourcemap manually as per the example in the grunt-autoprefixer repo, but whatever I do the comment - /*# sourceMappingURL=style.css.map */ gets stripped from the file and source maps don't work in chrome.
EDIT: Sorry, I just got it to work by using:
sourcemap: {
options: {
map: true
},
src: 'library/css/style.css',
dest: 'library/css/style.css' // -> dest/css/file.css, dest/css/file.css.map
},
I'd be interested to know, for performance reasons, do I need to bother specifying a sourcemap option at all in the grunt-contrib-sass config now? It takes me about 2.4s to compile so every 0.1s counts!

Answer 1

Sorry, I just got it to work by using:
sourcemap: {
options: {
map: true
},
src: 'library/css/style.css',
dest: 'library/css/style.css' // -> dest/css/file.css, dest/css/file.css.map
},
I'd be interested to know, for performance reasons, do I need to bother specifying a sourcemap option at all in the grunt-contrib-sass config now? It takes me about 2.4s to compile so every 0.1s counts! I'll do some testing and see, as far as I can see it looks like source maps are generated by default now by sass, so I probably only need to specify this in autoprefixer

Answer 2

I found the following worked for me:
sass: {
options: {
sourceMap: true,
sourceMapEmbed: false
},
dist: {
files: {
'css/style.css': 'css/src/style.scss',
'css/debug.css': 'css/src/debug.scss',
}
}
},
autoprefixer: {
//prefix all files
multiple_files: {
expand: true,
flatten: true,
src: 'css/*.css',
dest: 'css/'
},
options: {
map: true,
annotation: false
}
},
Without specifying annotation: false, I found that autoprefixer always overwrote the /*# sourceMappingURL=style.css.map */ with a data-uri sourceMappingURL that would not work (my browser inspectors would not show the original .scss source).
I also found that using sourcemap as in the accepted answer does not work if you have multiple scss/css files. I believe sourcemap allows you to set a different set of options for each scss->css mapping, but I wanted the same settings for all of mine.
Hope this helps!