With Grunt, how can I compile all *.less files, if I have global mixins and constants? - gruntjs

Question

I want to organize my HTML, JS, and LESS by module. I'm already using Grunt to compile *.js and *.html from my source folders.
So I configured grunt as follows:
grunt.initConfig({
less: {
ALL: {
files: { 'compiled.css': '**/*.less' }
}
}
}
But this runs into a major problem: constants and mixins from my /helper/*.less files are not accessible to other .less files.
It seems like grunt-contrib-less compiles each individual .less file, and then combines the output, but doesn't compile anything "globally".
The only solution I can think of is to create and maintain a master.less that #imports each individual .less file. But I'm trying to achieve an extremely modular build process, and I don't have to list any HTML or JS files, so I'm really hoping to find a *.less solution too!

Answer 1

Thanks to #seven-phases-max for the following answer!
less-plugin-glob
Allows you to use wildcards in #import statements! Works perfectly!
// master.less
#import "helpers/**/*.less";
#import "modules/**/*.less";
And all you need to add to your Grunt configuration is the plugins option:
// Gruntfile.js
grunt.initConfig({
less: {
'MASTER': {
src: 'master.less',
dest: 'master.css',
options: {
plugins: [ require('less-plugin-glob') ]
}
}
}
});
And, don't forget, npm install less-plugin-glob.

Answer 2

Here's one way to achieve an effortless development experience.
However, it requires a generated file and a custom task.
Auto-generate the master.less file
Create a task that generates master.less by writing an #import statement for each *.less file:
grunt.registerTask('generate-master-less', '', function() {
generateFileList({
srcCwd: 'modules',
src: '**/*.less',
dest: 'less/master.less',
header: '// THIS FILE IS AUTOMATICALLY GENERATED BY grunt generate-master-less\n',
footer: '// THIS FILE IS AUTOMATICALLY GENERATED BY grunt generate-master-less\n',
template: '#import "<%= filename %>";\n',
join: ''
});
});
function generateFileList(options) {
var _ = grunt.util._;
var files = grunt.file.expand({ cwd: options.srcCwd }, options.src);
var results = files.map(function (filename) {
return _.template(options.template, { 'filename': filename });
});
var result = options.header + results.join(options.join) + options.footer;
grunt.file.write(options.dest, result);
}
Then, use grunt-contrib-less to just build master.less.