Custom CoffeeScript compilation with GruntJS - coffeescript

Question

I have a Gruntfile, which takes all *.coffee files from a certain folder, and compiles them to JS files, keeping the same folder structure (if any).
So with a folder structure like:
scripts
|--widgets
| |--a.coffee
|--vendor
| |--b.coffee
|--c.coffee
|--d.coffee
It will generate the same folder structure, but with JS files instead of Coffeescript files. I would like to have a separate rule for the widgets folder and the c.coffee file, ie. I want to compile all of the contents of widgets and c.coffee into one single file.
How can I exclude one file and one folder from the files property of the grunt object? This is the code I'm currently running:
files: [{
expand: true,
cwd: '<%= params.app %>/scripts',
src: '{,*/}*.{coffee,litcoffee,coffee.md}',
dest: '.tmp/scripts',
ext: '.js'
}]
I've also seen that there are 2 syntaxes to declare files. One is as an object, and one as an array (what I have above). What is the difference and would the other declaration better help me in my case?

Answer 1

The documentation on configuring grunt tasks has some words on what you want. Actually, there are four ways to define a files property, of which one is deprecated.
Here is a Gruntfile.coffee, because it is shorter. Use the File Arrays Format with exclusion patterns for the compile subtask and the Compact Format for the compileJoined subtask. I hope you use grunt-contrib-coffee. grunt-coffee is out of maintenance for almost two years now and doesn't seem to have a join option.
module.exports = (grunt) ->
grunt.initConfig
params: app: '.' # ignore this, it's just that this file works as expected.
coffee:
compile:
files: [
cwd: '<%= params.app %>/scripts'
expand: yes
src: ['**/*.{coffee,litcoffee,coffee.md}' # everything coffee in the scripts dir
'!c.coffee' # exclude this
'!widgets/**/*'] # and these
dest: '.tmp/scripts'
ext: '.js'
extDot: 'first' # to make .js files from .coffee.md files
]
compileJoined:
options: join: yes
# sadly you can't use expand here, so you'll have to do cwd "by hand".
src: [
'<%= params.app %>/scripts/c.coffee'
'<%= params.app %>/scripts/widgets/**/*.{coffee,litcoffee,coffee.md}'
]
dest: '.tmp/special.js'
grunt.loadNpmTasks 'grunt-contrib-coffee'
here's a small output from script, it seems to work:
$ tree scripts
scripts
├── c.coffee
├── d.coffee
├── vendor
│ └── b.coffee
└── widgets
└── a.coffee
2 directories, 4 files
$ rm -rf .tmp
$ grunt coffee
Running "coffee:compile" (coffee) task
>> 2 files created.
Running "coffee:compileJoined" (coffee) task
>> 1 files created.
Done, without errors.
$ tree .tmp
.tmp
├── scripts
│ ├── d.js
│ └── vendor
│ └── b.js
└── special.js
2 directories, 3 files
$ cat scrips/c.coffee
variableInC_coffee = "a variable"
$ cat scripts/widgets/a.coffee
variableInC_coffee = variableInC_coffee.replace /\s+/, '_'
$ cat .tmp/special.js
(function() {
var variableInC_coffee;
variableInC_coffee = "a variable";
variableInC_coffee = variableInC_coffee.replace(/\s+/, '_');
}).call(this);