What am I doing wrong with Gruntjs targets? - node.js

Question

I followed the instructions on the grunt.option page to create different configurations for different environments/targets such as development, staging, and production in my Gruntfile. However, upon doing so I found that my tasks silently fail.
I've reduced the problem to a very simple example. The following Gruntfile fails to build the file:
module.exports = function (grunt) {
grunt.initConfig({
pkg: grunt.file.readJSON('package.json'),
less: {
dev: {
options: {
compress: true
},
build: {
src: ['src/css/test.less'],
dest: 'build/css/test.css'
}
}
}
});
grunt.loadNpmTasks('grunt-contrib-less');
grunt.registerTask('default', ['less:dev']);
};
The output in my terminal is the following:
$ grunt
Running "less:dev" (less) task
Done, without errors.
If, however, I use the following Gruntfile, the build output is as expected:
module.exports = function (grunt) {
grunt.initConfig({
pkg: grunt.file.readJSON('package.json'),
less: {
options: {
compress: true
},
build: {
src: ['src/css/test.less'],
dest: 'build/css/test.css'
}
}
});
grunt.loadNpmTasks('grunt-contrib-less');
grunt.registerTask('default', ['less']);
};
The terminal output for this Gruntfile reflects the built file:
$ grunt
Running "less:build" (less) task
File build/css/test.css created.
Done, without errors.
What am I doing wrong in the first Gruntfile? What is it that I am missing about this task:target convention?

Answer 1

Your first Gruntfile - If you want per-target options, you need to specify the files object. So your code would be something like this:
less: {
dev: {
files: {
"build/css/test.css": "src/css/test.less"
}
},
production: {
options: {
compress: true
},
files: {
"build/css/test.css": "src/css/test.less"
}
},
}
Basically in your first Gruntfile build is an unknown object. Your target is named dev and grunt-contrib-less doesn't have an option called build so Grunt doesn't know where to write the files. Your second Gruntfile works because you set the options as a global. Use the above code if you want per-target options.